Volume 31

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Author: Steve Wong

PP: 36

Direct rooting of tissue-cultured rhododendrons into an artificial soil mix was highly successful. By by-passing the standard test tube pre-rooting stage in the laboratory, production costs are markedly reduced. If a suitable environment is maintained in the propagation tent, root initiation will occur within 3 to 4 weeks of planting.

Author: George F. Ryan

PP: 83

Several herbicides are available for use in nursery containers. Each one differs from the others in the weed spectrum it controls, the way it behaves in the container growing medium, and its tolerance by nursery plants.

One of the most useful of the chemicals now available is oxadiazon (Ronstar or Ornamental Herbicide I). It controls a broad spectrum of annual grass and broadleaf weeds, including bittercress (Cardamine oligosperma) which has been a hard weed to control either by hand or with chemicals. Oxadiazon is available only in granular formulations that should be applied when nursery stock foliage is dry to avoid leaf burn. The granules should be washed off thoroughly with irrigation before the foliage becomes wet with dew or light rain.

Control of annual grasses and some broadleaf weeds will be strengthened if oxadiazon is supplemented with napropamide (Devrinol) or oryzalin (Surflan). Common chickweed and mouseear chickweed, in particular, are not controlled by oxadiazon.

Another weed that


Author: Dixon P. Hoogendoorn

PP: 501

Grafting upright junipers is an ancient process in the field of plant propagation. Many articles and papers have been published in various past IPPS Proceedings dealing with this particular subject.

We do not specialize in upright junipers, however, we do grow Juniperus chinensis ‘Robust Green’, and J. chinensis ‘Keteleeri’ to diversify our line of ball and burlap material. We have grown ‘Keteleeri’ for many years and like it for the simple reason that it has a full, compact growth habit right to the ground, as well as deep green foliage. ‘Robust Green’ has been a welcome addition over the last few years because of its dense and dark green color which complements its irregular form. Both cultivars seem to adapt to our changeable and sometimes harsh weather conditions in New England.

As did many nurserymen years ago, we used J. virginiana as an understock for grafting. It made an excellent understock, however, the ever present phomopsis blight problem made


Author: Douglas J. Chapman, Susan Hoover

PP: 507

The specific objectives of this investigation (a study initiated in 1979) include (1) how many different tree species can be commercially propagated by softwood cuttings and when; (2) encouraging development of cultivars adapted to specific regions, e.g. Great Lakes cultivars; and (3) stimulate local nurserymen to propagate regional cultivars or stimulating the establishment of local propagation firms with the above goals(1).

Author: B.E. Tankersley, E.R. Emino

PP: 512

Modified French and mound layering techniques were evaluated as methods of propagating Acer grandidentatum. Nutt French layering was successful in one year. Layers with greater than 0 5 cm caliper stems were successfully established in containers while less than 0.5 cm caliper layers did not survive transplanting. A longer time period is required for evaluation of layering techniques. Although these results are from limited observations, some success was obtained by layering, while more extensive efforts at cutting propagation were not successful.

Author: Joerg Leiss

PP: 515

Up to a few years ago the Japanese tree lilac had been known as Syringa amurensis var. japonica in the trade. The confusion in naming comes from the many botanists that described the tree.

Blume described it in 1855 as Ligustrum reticulata. Maximowicz in 1875 used the name Syringa amurense var. japonica. This name was also used by Franchet and Savatier in 1879. However, Hara is to be credited with the now valid name, Syringa reticulata.

In 1876 Dr W.S. Clark of the Agricultural School in Sapporo, Hokkeido, Japan sent seeds to the Arnold Arboretum where it was grown under the Accession #1111. One can surmise that considerable seed was sent because within 8 years nurseries such as Ellwanger and Barry of Rochester and H.H. Berger of San Francisco besides various nurseries in Europe listed the tree for sale. It is a small tree growing to 10 m. with a peeling shiny bark similar to cherry. It is usually multi-stemmed and flowers toward the end of June with immense, terminal white flower cluster


Author: Thomas M. Marino

PP: 518

For the past 30 years, forestry in the southeastern United States has been devoted to genetic improvement of pine trees (21). Major interest in tree improvement has concerned loblolly pine (Pinus taeda L.) though longleaf (Pinus palustris Mill.), slash (Pinus elliottii Engelm. var. elliottii) and shortleaf (Pinus echinata Mill.) pines are also important. Straightness of bole, branching characteristics and large volume are a few of the traits being examined. Improvement of these desired traits has been through the process of sexual propagation; that is, through controlled breeding to produce improved progeny for successive generations (15). Recently, there has been an increased effort among research foresters to capture these desired traits through asexual propagation by rooting. Since pines in general are difficult to root (18), obstacles have been encountered.

Asexual propagation by rooting allows for a greater recovery of the genetic potential of a tree more quickly than through


Author: Richard E. Cross Sr

PP: 524

The cutleaf staghorn sumac is a very hardy form with bright green leaves, deeply cut foliage and good fall coloration. It is sometimes referred to as fern leafed sumac.

The propagation and growing of this attractive plant is not a very common practice in midwestern nurseries. This creates a good demand and we are always sold out before our season is over. There are only a few nurseries who grow it.

The procedures described are our own methods and derived from a trial and error procedure over a period of more than ten years. We have found it to be a somewhat difficult and inconsistent subject but by using large numbers and being persistent, we have always had a crop of plants for sale.

Growing conditions. It is one deciduous item we can grow and produce to saleable sizes in one season's growth. Our growing season in Southern Minnesota is normally about 115 days with precipitation averages of nearly 30 inches per year.

Our soils are a silt-loam type and very moisture retentive. We do not


Author: Donald F. Dillon

PP: 527

At Four Winds we produce over 30 citrus cultivars which are useful to the home gardener for their fruit production, their beauty as an evergreen, and for their flavors and aromas. Cultivars are chosen to ripen at many different times of the year, offering the home owner a great variety in choices.

Our trees are produced by a method called twig-grafting, developed originally by Halma and Frolick at UCLA a good many years ago. The details of our production methods, our history and our greenhouse operations are covered in an earlier paper at a western Region meeting in San Dimas in October of 1962. At this time we'll attempt only to give a brief review of things that have occurred from 1962 to the present date, and some changes that we have found necessary. Our production involves the use of fresh new twigs — those that first appear from the spring flush and are hardened off to the point where we begin our work in May or June. Cuttings are taken from both scion and understock mother


Author: Paul L. Smeal, James S. Coartney

PP: 532

It has been 20 years since attending my first Plant Propagator's meeting in Washington, D.C., and, after attending some 16 IPPS meetings and over 100 nurserymen's short courses, nursery tours and trade shows, the same question always asked is "what's new?" Plant propagators and nurserymen are always looking for that new chemical which gives 100 percent rooting, or the new fertilizer or pesticide that solves all problems, or the machine that ends all labor. One hates to disappoint the inquirer, but the magic chemical or the magic machine still has not been found. The successful propagator must continue to rely on "common sense" to solve plant propagation problems.

Prior to propagating any plant, there are questions or things to consider in the planning stage. First, what plants to propagate? Then, how many to propagate, how much propagation space is required, equipment and supplies needed, and the time involved? After these questions have been answered, then one has to


Author: Hans Hess

PP: 535

There are many different things to consider in the production of evergreens from seed. I believe one of the more important is the source of the seed you buy. For example, Douglas fir seed from the Rocky Mountain area of Colorado is hardy and has a medium growth rate. Seed of the same species coming from Oregon and Washington at elevations of 500 to 600 feet is much less hardy and has a far more rapid growth rate.

Juniperus virginiana from mid western sources will be crossed with Juniper scopulorum and will not resemble the true eastern red cedar. White pine is available from New York the lake states and the south. for planting in northern areas New York and lake states seed is the most desirable.

A seedling business that is going to be successful should provide a continuing supply of seed selections each year. This can be a problem if you buy seed on a year to year basis and there is a no crop situation on one or more plants. To prevent this problem a grower should provide himself with


Author: Wayne Lovelace

PP: 537

Production of tree and shrub seedlings in open field beds presents many management factors not present in more controlled seedling production programs such as greenhouses, coldframes, and other protected structures. It represents one of the more intense types of field production often exceeding 200,000 plants per acre. An investment with this potential requires as much pre-planning and technical management as possible in order to produce the desired size and quality seedling at the least possible cost. Many factors affect this production, presenting opportunities for profit when properly implemented.

Author: Beverley R. Greenwell

PP: 85

The base of a soil mix is very important in successful container growing. The mix needs to have a high water holding capacity, with sufficient porosity to give rapid drainage and aeration. It also needs to be retentive of nutrients and free of weeds, insects and diseases. Soil based mixes, in our climate, are generally poor.

The weather in the southwest corner of British Columbia is very wet in fall, winter and spring but we can usually expect a long stretch of hot, dry, weather during the summer. With this weather pattern in mind — we must steer clear of any mixes containing soil; they are just too heavy to withstand our three seasons of monsoons. Our mix MUST drain freely and the beds underneath the containers must also drain freely.

The mainstay of our mix is a sawdust:peat mixture in 3:1 proportions. Some growers add about 10% sand. Hemlock ot fir sawdust is generally used, as it is the most readily available and the least expensive of the common wood waste material. Bark or bark:peat mixes


Author: Ann E. Fagan, Michael A. Dirr

PP: 542

Liriope muscari (Decne.) Bailey, big blue liriope, is one of the most commercially important groundcovers in the southeastern landscape, and is also widely used in the southwest and California. Hardy to Zone 6, it could be used in additional geographic areas. The 1 to 2 foot grass-like evergreen foliage; lilac-purple flowers borne on a spike above the foliage; sun and shade tolerance; and adaptability to a wide range of soil types are traits contributing to its popularity. Liriope displays a high degree of salt tolerance which makes it particularly useful in coastal landscapes (5,20).

Abundant blue-black, single-seeded berries are produced on upright spikes in the fall. Seeds are globose and the embryo is surrounded by copious, hard endosperm A deep blue-black skin envelopes a purple, pulpy inner matrix (collectively called pulp). Seed appears to be a logical method of propagation, although division, which is not only time consuming but expensive, is the only method referred to in the



PP: 554

The Question Box session was convened at 3 50 p m. with Ralph Shugert. Bruce Briggs, and Hudson Hartmann serving as moderators.

MODERATOR BRIGGS: Why shouldn't methanol be used to make an IBA solution?

MICHAEL DIRR: Methanol has been mentioned as a solvent for a lot of the auxins. You could use it if you want, however, I would shy away from it because it is wood alcohol. Wood alcohol can cause blindness if ingested.

MODERATOR BRIGGS: What is Synergol?

MICHAEL DIRR: It is an English product that is an IBA-NAA COMBINATION.

ED LOSELY: I believe that the K salt of IBA is one of the primary ingredients in Synergol.

MODERATOR BRIGGS: What are some sources of IBA and NAA?

RICHARD ZIMMERMAN: My only experience is with tissue culture. In tissue culture we must have it. The amount is not important. Ed Bunker has reported that with Grevillea they take very soft cuttings and drop them in a bucket of water containing ½ cup sugar per 2 gallons of water. The cuttings are left in for 30 minutes and then wrapped in newspaper over night. He reported less wilting


Author: Richard H. Zimmerman

PP: 559

Tissue culture has become an important tool for use by the commercial plant propagator. This technique offers a number of advantages including easier production of many difficult to propagate plants, rapid increase of newly introduced cultivars and the ability to propagate desired plants continuously or at any time throughout the year. When the micropropagation aspects of tissue culture are combined with appropriate indexing and explant establishment techniques, then tissue culture provides the opportunity of producing large quantities of vigorous, uniform plants free of known diseases.

Establishing a tissue culture production facility requires a considerable investment in time and money although methods for minimizing these costs have been described (6). In addition, the unit cost of micropropagated plants can be higher, sometimes considerably higher, than the cost of conventionally propagated plants. This cost may be acceptable, depending upon the purpose for which the plants are being


Author: Ellen Sutter

PP: 563

Micropropagation by in vitro techniques has the potential of replacing conventional methods of propagation for many horticultural crops. But several serious problems must be solved before micropropagation becomes profitable on a large commercial scale. One serious problem is the high rate of loss of cultured plants of many species when they are transferred to the greenhouse or to the field. These plants are characterized by rapid and severe desiccation unless they are nurtured in a protective environment for the first 1 to 2 weeks after they are removed from culture. Studies indicate that abnormalities in the morphology of cultured plants may cause this desiccation by blocking water flow through the plant. Morphological abnormalities of the root-shoot junction, leaf anatomy, and the cuticular surface have special relevance to the problem of desiccation

The root-shoot junction has been shown to be morphologically abnormal in cultured plants in several species. In Pelargonium × hortorum


Author: R.J. Henny

PP: 568

We have been conducting breeding studies within the genera Dieffenbachia and Aglaonema, which are both members of the Araceae family. Two goals of this program are: A) development of new and better cultivars for commercial production in Florida and; B) to study the biology of their reproductive mechanisms and how it relates to other tropical plants. Our studies have included more than 50 distinct types of dieffenbachia and 15 different aglaonemas. The following discussion will center on the more important factors we have discovered which affect the breeding potential within these genera.

Stock plants are grown in greenhouses or shaded slat sheds with light intensities of 1500–2500 foot candles and a temperature regime of 65–95°F. Under these conditions, most dieffenbachia tend to produce a seasonal flush of blooms from April through June. Aglaonemas usually begin to flower in May and continue through June. However, some plants that we wanted to hybridize never seemed to bloom


Author: Bryce H. Lane, Steve Still

PP: 571

Terminal unbranched Acer rubrum L ‘Red Sunset’ cuttings were propagated in June, July and August, 1980. Cuttings were stuck in an Osmocote 18–6–12, 5 4 kg/m3 amended medium, a 20–20–20 (200 ppm N) liquid fertilizer applied to the medium, or a control medium containing no fertilizer, and placed under a 4 hour extended or natural photoperiod. The cuttings had higher rooting percentages when they were propagated in June and July under an extended photoperiod, regardless of fertility. Cuttings propagated in August had significantly lower rooting percentages for all treatments. There were no differences observed in rooting percentages, or root dry weights, due to fertilizer in the rooting medium for cuttings propagated in a natural photoperiod. Cuttings had greatest root dry weights when they were rooted in an Osmocote-amended medium, and under an extended photoperiod.

Author: Jack Alexander, Peter Del Tredici

PP: 579

MODERATOR DEL TREDICI. Our first speaker today is Jack Alexander.

JACK ALEXANDER Syringa pekinensis, a native of China, is a small tree seldom reaching 25 feet. The most attractive specimens have exfoliating, cinnamon brown bark that peels off in strips. This characteristic varies greatly between specimens and the plant may display a cherry like bark similar to the Japanese tree lilac, S. reticulata.

To be assured of exfoliating bark we should propagate only from specimens exhibiting this characteristic. Cuttings are difficult-to-root and grafting or budding may be necessary for asexual propagation. Seed from attractive plants may yield satisfactory results and have the added benefit of variation, from which we might select superior clones.

The flowers of the Chinese tree lilac appear at about the same time as the Japanese tree lilac and are also creamy white The leaves of S. pekinensis are smoother, less oval shaped than S. reticulata and more closely resemble the leaves of the common


Author: Lloyd Moden

PP: 588

The weed control methods that will be covered here are ones that have been used by Mid-Western Nurseries at our Tahlequah, Oklahoma growing facility. Tahlequah is in the northeastern part of the state and most of our soils are loam to silt loam and clay loam. The field soils average about 2% organic matter. Our annual precipitation is 46 inches.

Author: Carl E. Whitcomb

PP: 591

A container was designed to prevent root circling and stimulate root branching. A test with the air-root-pruning container using Pyracantha ‘Mojave’ showed an increase in top and root weight, number of branches per plant and number of 2 in long roots 10 days after transplanting of 63, 38, 158, and 187%, respectively, compared to plants grown in conventional containers. This container nests for shipping, can be filled by existing potting machines and can be handled and stacked for plant shipping like conventional containers.

Author: Richard J. Stadtherr

PP: 598

Over 200 different kinds of plants were investigated over eight years for their adaptability, hardiness, propagation, maintenance, and general suitability for use as ground covers on slopes, medians, and flat areas along highways in Louisiana Rating for overall appearance, weed presence and crop establishment over a 13 month period indicated that liriope rated highest significantly Lonicera japonica ‘Purpurea’, Trachelospermum asiaticum and Wedelia trilobata rated highly also Wedelia kills back to the ground after exposure to 28°F. The others are evergreen.

Author: H.B. Tukey Jr

PP: 88

Above-ground part plants — leaves, stems, branches and flowers — can absorb nutrients, pesticides and growth regulators from sprays. For almost seventy years, growers of commercial crops have used foliar sprays of nutrients to control minor element deficiencies in fruit plantings. Today, there is renewed interest in foliar nutrition due to increased cost of fertilizer, environmental concerns about nutrient applications to soil which may be carried into ground water supplies, and better knowledge of the plants that we grow. The main advantages of foliar nutrition, as compared to root applications, are (a) more rapid and (b) more efficient absorption of nutrients (3). To utilize these advantages, we must know the growth patterns of plants and when to apply nutrients for best effect.

Several environmental factors affect foliar absorption. For example, an increase in temperature increases foliar uptake due, in part, to an effect on processes of penetration. In addition, there is a great


Author: Grady L. Wadsworth

PP: 605

Greenleaf Nursery Company has two growing areas. Our original location, near Tahlequah, Oklahoma, consists of 310 acres and is located on the rolling, rocky hills adjacent to Lake Tenkiller. The second growing area was located in El Campo in 1971. Gil Nickel and Austin Kenyon selected the area for its mild climate and closeness to large and developing metropolitan areas of Texas.

They liked the level land and the deep black clay which would make it easy to prepare growing beds Due to the levelness of the land they decided to reverse the block design; instead of the block's being crowned it would slope to the center. This would allow the roads to be built on the crown and assure good drainage of the roadway and block.

We contacted the Texas Highway Department and road building firms to see what preparation should be made to the base. They recommended lime stabilization. We put in 8 test areas where we incorporated lime at the rate of 10 lb/sq yd and compared them to areas with no


Author: Steven A. Hottovy

PP: 608

Hines Wholesale Nurseries operates a 200-acre container nursery approximately 20 miles west of Houston, Texas. Construction of this facility has been completed over the past 3 years. Hines Nursery grows 227 cultivars of ornamental landscape plants in several size containers. The nursery averages 170 employees during the year with seasonal fluctuations.

At the hub of the nursery is the propagation department. This branch of the nursery has been developed over the last two years and now occupies 9.6 acres Propagation is divided into three departments. cutting, potting and liner maintenance. Propagation produced 3 million potted liners for canning and liner sales in 1981. These liners were started as rooted cuttings, seedlings or divisions. In 1982 a grafting and a spore program will be initiated.


Author: George Todd Jr

PP: 612

Speedling means different things to different people. To some, Speedling is the grower of quality transplants, to others a pioneer in the automation of transplant production. To still others, Speedling is the manufacturer of greenhouses, water systems, and flats that enable them to grow their own transplants. Most of our plants are presently marketed in the eastern part of the country.

The containerized transplant has obvious advantages over a bare-root plant. Primarily, these are uniformity in plant height as well as root system and the absence of transplant shock because the roots are not torn apart when the plant is pulled.

The Speedling system can be used on virtually every transplant crop. In the early days, our production was limited to vegetables. It has now expanded to include ornamentals as well as tree seedlings.

The first Speedling plants were produced in 1967 in the patented Todd Planter Flat. Other growing containers were available. However, a cylinderical container


Author: George Itaya

PP: 616

The procedure of budding magnolias at Saratoga Horticultural Foundation evolved for several reasons. For our purposes propagation by budding was superior to propagation by cuttings or grafting since the necessary controlled greenhouse environments and structures were unavailable. Budding also allowed us to conserve our propagation material at the time our magnolia cultivars were introduced and the stock of these new cultivars was limited. Now our small acreage does not allow the extravagant use of space necessary for the stock plants that would be required to produce the same quantity of magnolia cultivars we produce by budding.

Saratoga Horticultural Foundation propagates four selected cultivars of Magnolia grandiflora, namely ‘Russet’, ‘Samuel Sommer’, ‘San Marino’ and ‘St. Mary’. The production schedule and budding techniques are the same for all of them.


Author: Bill Curtis

PP: 619

For many years I have propagated magnolias, both evergreen and deciduous, from cuttings, using coarse sand and perlite, or sand and pumice, half and half, for the rooting medium, treating with Hormodin #3 (0.8% IBA in talc), and using bottom heat, 75° to 78° F. The technique that seems to work best is to wound one side before applying the hormone. With such high bottom heat, watering is critical.

The deciduous cultivars are propagated using summer cuttings under intermittent mist, on 3 to 5 sec/6 min. If wood is available, we use a 4– to 6– inch heel cutting. Mid-July or early August seem to give the best results. You cannot set a definite date by the calendar. The wood is ready when the terminal snaps easily We take the tip out of the cutting, which will generally leave a 2– to 3– inch cutting of the magnolias such as M. soulangiana, M. stellata, and most of the Kosar hybrids. M. soulangiana ‘Rustica Rubra’ cuttings will be much longer. I like to take the cuttings off field stock in vigorous


Author: Dexter McDonald

PP: 621

The bedding plant, by nature, is a quick-turn commodity that moves rapidly through production, through the retailer and into the homeowner's garden in a relatively short period of a few weeks We also find that the marketable life expectancy of most bedding plants is only 3 to 4 weeks on the average.

As with most any crop, it must be emphasized in the beginning that cultivar selection, scheduling, and production operations vary with the change of geographical location of the growing grounds. Temperature highs and lows, light intensity, as well as coastal conditions, air pollution, and other environmental factors all influence one's approach to bedding plant production. Our bedding product is not only grown year-round in California and Arizona, but a large portion of that product's production time is spent outside under mother nature's influence, over which we have little control.


Author: George H. Lacy, Robert C. Lambe, Cynthia M. Berg

PP: 624

Iris soft rot, previously reported to be caused by Erwinia carotovora subsp carotovora, was correlated positively with the intensity of sprinkler irrigation rather than iris borer damage in a commercial rhizome production operation in Virginia Erwinia chrysanthemi was consistently isolated from the rotted plants and reproduced the symptoms observed in the field in artificially inoculated healthy plants. Erwinia carotovora subsp. carotovora> and garden slug damage were associated with a minor outbreak of soft rot in a greenhouse. Both bacterial pathogens were reduced in viability by exposure to sodium hypochlorite and the incidence of soft rot was reduced on sprouting rhizomes in greenhouse tests, especially when treated with 20 mg Cl/liter (20 ppm Cl). However, the effectiveness of chlorination was reduced in some water sources or when the number of bacteria suspended in the water was increased.

Author: P.F. Colbaugh, S.J. Terrell

PP: 634

Soil-borne diseases are important constraints to efficient production of many types of greenhouse crops. Direct plant losses and delayed growth of crops affected with various types of root and stem rotting diseases contribute to higher production costs, unpredictable growth, and reductions in plant quality at the time of sale. Familiarity and use of sanitary growing practices advocated by Baker, et al. (1) are necessary for control of soil-borne diseases. The growing medium and container, the plant used for production and cultural operations are potential avenues of entry for soil-borne pathogens into the crop production cycle. Sanitary production practices can be effectively used to eliminate soil-borne pathogens from greenhouse production programs provided the procedures are uniformly adopted for all facets of the growing operation.

Author: Len Spencer

PP: 641

The Spencer Company entered the horticultural services field in 1959 in commercial landscape management. During the early 1970's we noted the environmental trend and began an indoor plant leasing service, which is now producing about 55% of our gross revenues. In 1977, the landscape division rounded out our services with landscape design-and-build capabilities.

For this presentation, I requested a brief statement from three department managers in our indoor division with regard to the needs you might address in your propagation, growing and shipping operations. These are their memos to me.


Author: Fred T. Davies Jr, Yui-Sing Fann

PP: 643

New techniques are needed to produce Texas field rose bushes more efficiently. A high percentage of successful bud unions was obtained by bench chip budding dormant roses with either a conventional budding knife or Liliput tool. Bench chip budding and utilizing selected forcing techniques to overcome initial dominance of understock axillary buds may help reduce the two year production period for producing field roses.

Author: R.G. Linderman

PP: 91

The associations of beneficial fungi with most plant roots are called mycorrhizae and have been described by me and others in past meetings of the International Plant Propagators' Society (2,3,5,6,7,9,10,11,13), and in extensive literature. There is, however, considerable need to better understand the nature of these symbiotic relationships in order to exploit their benefits in commercial nursery production. The microbiological aspects of container production offer special opportunities for exploration as well as some special challenges. My purpose in this presentation is to briefly discuss our current thinking in relation to the establishment and performance of these fascinating fungi. In other words, how and when should we inoculate container plants, and what must we do to ensure their survival and maximize their chances to enhance growth and survival of their host plants.

Mycorrhizae: form and function. In general, mycorrhizae are of two types: endomycorrhizae and B>ectomycorrhizae


Author: John C. Walter

PP: 648

Rose plants have been produced in east Texas for many years where the acid, sandy soil and rainfall are favorable for production of roses as a field crop. It is important that the fields be well-prepared. We begin field preparation in 1981 for the 1983 season.

It takes over 2 years to produce a salable rosebush. The production cycle begins in early November with cutting the budwood from desired cultivars. We use plants that will be dug and marketed this year. The mature wood is deleafed, wrapped in freezer paper, and then in damp newspaper, placed in plastic bags, and stored at 28°F until time to be used next May.

Next, the switches of rootstock are cut from the field that was budded this last year The switches are sawed into 6-inch long cuttings, de-eyed (lower eyes cut out leaving only 3 eyes on the top portion of each cutting), placed in bundles of 100, and put into large plastic bags for storing at least 2 weeks at 34°F before planting. In January, the cuttings are planted along the


Author: Jaime E. Lazarte

PP: 649

Plant tissue culture is a term used to describe in vitro plant propagation in a nutrient medium. Tissue culture uses the totipotency capability of plant cells to differentiate, develop, and grow into a plant (plantlet) from excised plant tissues (explants) (Figure 1). The first requirement for successful tissue culture is obtaining aseptic or sterile condition of the explants, laboratory, and medium to produce clean uncontaminated cultures. This is referred to in the literature as Stage I or "Establishment of Cultures". The type of explants (leaves, roots, shoots, etc.), the conditions of growth of the stock plants (indoors, outdoors, healthy), and the chemical used (sodium or calcium hypochlorite, benzalkonium chloride, ethanol) as sterilizing agent with the interaction of concentration-time of treatment, have a direct effect on the success of the establishing stage.

Author: Sidney B. Meadows

PP: 655

For generations nurserymen have rooted cuttings in beds. When the cuttings rooted, they were uprooted and planted in soil beds. When these plants were large enough to transplant they were uprooted again. All of this uprooting put growth on hold and took time and effort.

In the last decade direct rooting has become standard procedure with many nurseries throughout the century. No particular nursery or nurseryman could claim the distinction of originating the system because a considerable number of nurserymen embraced the concept at the same time. Evidently the time for this significant development had arrived and many saw fit to give it a try. There is no particular time when one could say direct rooting was born because there have been isolated instances of the practice going on for some time. In a meaningful way the system was basically born during the seventies.

From the beginning there was a considerable saving of time and labor. There have been many refinements and developments


Author: Thomas J. Banko

PP: 658

Cuttings of Juniperus chinensis L ‘Hetzii’ were rooted at monthly intervals over a 2-year period with IBA treatments of 0, 2000, 4000, or 8000 ppm Rooting varied greatly over this period, but was consistently poor in early spring (March) IBA did not significantly improve rooting percentages when rooting capacity was low, but did increase numbers of roots per cutting during favorable rooting periods. Trimming the upper half of the leaf from the cuttings also had no effect on rooting In another experiment, rooting medium temperatures of 20° and 25°C improved rooting of cuttings of J virginiana L ‘Skyrocket’ and ‘Hillspire’, and J chinensis L ‘Kaizuka’ Cupressocyparis leylandii rooted equally well at 15°C.

Author: H.G. Ponder

PP: 666

Much has been written about trickle irrigation and drip irrigation. So much has been written in fact, that there has arisen some confusion of how trickle irrigation relates to drip irrigation. The answer is that they are one and the same. Different authors generally choose one of the terms. In this country trickle irrigation seems to be the more popular term and, in fact, more accurately describes this irrigation system. This paper will henceforth use the term "trickle irrigation."

It is now time that we ask ourselves the question — What is trickle irrigation? One definition is that trickle irrigation is the daily maintenance of an adequate portion of the root zone of a plant at, or close to, field capacity during the growing and production cycle (1) For a moment let's take a close look at what is really being said in this definition. First, trickle irrigation works on the principle of the prevention of drought stress, as opposed to correcting an existing water stress. Never allowing a


Author: David L. Morgan, Edward L. McWilliams

PP: 670

Acorns of the live oak (Quercus virginiana Mill ) failed to germinate when frozen or stored in dry peat moss. Stored in moist peat moss at 5°C (41°F), and at 21–30°C (70–86°F), they germinated but were heavily infected with soil-borne fungal pathogens at 3 months, rendering them unsuitable for planting. Acorns dried at 34°C (93°F) lost viability as they desiccated A 15% weight loss reduced viability to 66%, and 20% weight loss reduced germination to 4%. Acorns collected fresh from tree limbs germinated at higher rates than those collected from the ground, where they presumably had dried over time. There was an inverse linear relationship between CO2 evolution (an indicator of respiration) and percent weight lost through drying. Implications of seed storage in controlled atmospheres and at near-freezing temperatures are discussed.

Author: Charles Parkerson and Frank Willingham

PP: 676

The Southern Region Question Box was moderated by Charles Parkerson and Frank Willingham.

CHARLIE PARKERSON: We have had trouble controlling Thielaviopsis in our nursery and feel containers may be one source of infection. We are wondering about a container made to collapse like the separators in old-fashioned egg cases. It could be made of light-weight plastic and thrown away after one use. That would eliminate the necessity of attempting to sanitize used containers with methyl bromide or by other methods that may or may not be effective. In addition, the collapsible feature would make storage easy and the fact that many cells could replace many separate pots would cut down tremendously on handling and filling time. Is anything like this on the market; and if not, would there be enough demand to justify its manufacture?

BRYSON JAMES: Are all other parts of your system clean? I have found Thielaviopsis in peat pots.

JAMES BERRY: Could it be we just don't use a strong


Author: Tom Saunders, Lawrence Legg, James Coartney

PP: 681

Rooting of Rhododendron ‘English Roseum’ was most successful when the cuttings were basally wounded on two sides and were treated with Hormex #30 (3 0% IBA). Removal of the terminal bud also increased rooting and was additive to the response caused by wounding. Foliar applications and terminal bud applications of growth regulator were generally ineffective.

Author: Bruce Usrey

PP: 100

The individual we honor today for the Western Region Award of Merit has achievements so extensive that it is hard to choose where to start. His achievements cover more than a quarter of a century. One marvels that an individual could be involved in so many projects to benefit his industry and fellow man.

He has always been alert to new processes and procedures. Always among the first to experiment with new equipment and new supplies in an effort to produce a better plant. The propagation of plants by faster, more efficient methods is always a challenge. He has found a special challenge in tissue culture and is commercially producing many hundreds of thousands of plants by this method, including conifers, berry vines, apple trees, Kalmia, a long list of Rhododendron cultivars, and many other plants.

Generous with his time, he has been the prime mover in innumerable projects to benefit the nursery and florist industries, numerous youth groups, farm orgnizations, local schools and his


Author: W. David Lane

PP: 101

The experiments described in this paper illustrate some of the responses of shoot cultures to treatment with growth regulators and the manipulations made possible through their use. First examined are the growth regulator requirements of shoot cultures. Cytokinin, in particular, is required by most cultures but, in exceptional circumstances, may not have to be supplied in the medium. The optimum growth regulator concentration required for shoot or root growth varies considerably between species and cultivar; growth regulators supplied in the medium can interact with those produced by the cultures and result in dramatically different responses. Variant requirements probably caused by this effect influence rooting more than shoot growth, particularly in the cultivar M.9. Its roots initially develop into callus rather than roots when continually exposed to a normal concentration of auxin in the medium. Shoot cultivars can be manipulated by exploiting differences in their tolerances to growth regulator concentrations higher or lower than their optimum. This should make it possible to develop procedures for preventing back mutation of spur-type strains to standard growth habit and, used in reverse, may be useful for isolating and identifying new spur-type strains arising as induced mutations in shoot cultures.

Author: R.L. Ticknor

PP: 109

Three rooting hormone products: liquids, Dip n' Grow, and Wood's Rooting Compound, and the powder, Hormex No. 8, were compared for rooting efficacy on eight species during December. Results varied by species, but in more cases, a heavier root system was produced by the liquid products. The solvent system was changed on Dip n' Grow by the manufacturer and a new trial was conducted in May with two species using the new formulation. There were no significant differences with Forsythia × intermedia ‘Spring Glory’, but Wood's Rooting Compound appeared to be more effective at lower concentrations with Virburnum × burkwoodii.

Author: Ingemar Karlsson

PP: 112

Rooted cuttings of yellow cedar from young material reached a plantable size in one growing season. Two and four years after planting on typical sites, survival and height growth of the cuttings compared favorably to those of the seedlings. A hedging orchard was established from seed of selected parent trees in order to produce juvenile material for the large scale production of rooted cuttings and, in 1981, the first production of rooted cuttings for reforestation was begun.

Author: Edsal A. Wood

PP: 116

My first remembrance of using a liquid rooting hormone goes back to 1951 when I tried a 24 hour soak of English holly in ethanol and IBA. After reading in Hartmann and Kester's text (1) on plant propagation the advantages of liquid hormones I decided this was the way to go. Since that time I have been involved with improving my abilities in rooting cuttings as a commercial wholesale grower. My first tests with ethanol as a solvent showed that with certain water sources as a diluent, a precipitate would form. From there I went to additional solvents to prevent this. After trying many, I found improved rooting was because of better penetration of the hormone through the plant tissue, I determined to find the best additional solvent for penetration.

To me, the reasons for using a liquid hormone are many. Firstly, you can select the concentration best for the species or cultivars you grow. The best concentration for any given plant is varied because of climate, fertility, water, age of


Author: Richard H. Zimmerman

PP: 118

The term tissue culture, as popularly used, covers a multitude of cell, tissue, and organ culture techniques. The aspect of most interest to plant propagators is micropropagation, the rapid asexual multiplication in vitro of a desired plant. Most commonly, the explant used in micropropagation is a meristem-tip, shoot-tip, or bud that is induced to grow and then proliferate in culture. The basis of this procedure is the stimulation of new shoots in vitro by treatment with an appropriate plant growth hormone. A cytokinin in the culture medium stimulates growth of axillary and/or adventitious buds. The resulting shoots can then be rooted by transferring them to a medium free of cytokinin and containing an appropriate auxin concentration, or by rooting them directly in the greenhouse using more or less standard procedures. Micropropagation can also include the production of somatic embryos in culture, a process which is also under hormonal control. Propagation by somatic embryogenesis

Author: David I. Dunstan

PP: 39

The principal factors that have affected success at transplantation of micropropagated tree fruit rootstocks are presented. The factors discussed include pre-transplantation conditions (laboratory culture) and the conditions at transplantation and field-planting; examples are taken from the Kelowna Nurseries production.

Abbreviations used in the text:

     NAA     naphthalenacetic acid
     IBA       indolebutyric acid
     IAA       indoleacetic acid
     BA        benzyladenine
     MS        Murashige and Skoog
                   nutrient formulation (8)

Author: Arie Van Vliet

PP: 127

Boskoop. The nursery center of Boskoop is about five centuries old. In the old days mostly fruit trees and small fruits were grown. In the last 100 years only ornamental trees and shrubs, coniferous and broadleaf evergreens have been grown.

Today Boskoop is a nursery center of about 900 hectares (2200 acres). In this center we have 1000 nurseries, of which 900 are strictly growers, and 100 are growers and exporters. Of these, 45 percent have a nursery of about half hectare (a little more than one acre). They are full-time nurserymen and are one or two person operations. The average exporter has more employees which he needs in the packing and shipping season. In the summer they work in the exporter's nursery in which specialty items are grown for customers in the countries shipped to. Most exporters only ship to one or two countries and they will visit their customers once or twice a year.

Export. About 75 percent of the nursery stock grown in Boskoop is exported to about 75 countries.


Author: Edward J. Bunker

PP: 130

All of us know that many plants in our gardens are hard to propagate, and yet are very desirable. Amongst this group of plants are many of the Australian native shrubs. Selections of our Australian native plants have been made by enthusiasts and nurserymen and some hybridization has been carried out. Also some hybridization has happened in gardens. Many of these plants in flower are very spectacular but many of them are very hard to propagate in commercial quantities.

This paper is aimed mainly at rooting cuttings in the genera Grevillea, Melaleuca, Callistemon and Leptospermum, but I will finish with one or two observations and thoughts on micro cuttings of some foliage plants.

Of course it goes without saying that without the right cutting wood from parent stock, one has very little chance of getting good results. In work carried out in our nursery over the last ten years, we have developed some techniques in managing stock plants and getting very good results in the rooting of


Author: Fred W. De Wald

PP: 134

I started as a backyard nurseryman some 40 years ago. When I raised a few plants I found out that I had to buy a license to sell them, so on March 19, 1948, I got my first license. That was 33 years ago. When I outgrew the backyard I bought a small ranch, on the outskirts of Snohomish, Washington. De Wald Nursery sits on 7½ acres along the East bank of the Pilchuck river.

My latest project has been starting a small scale tissue culture laboratory for rhododendrons. Tissue culture is a very complex and special way of propagation but at my age and with no more scientific knowledge than I have I can make it work. There is a vast future in tissue culture for many of you younger and more qualified people.

If you have any success at all with tissue culture it will not let you stay small. It multiplies and grows. To start with I took an old refrigerator, then installed heat cables on a thermostat, Gro-Lux lights on a timer, and a fan to circulate the air and keep it cool. In the refrigerator


Author: Wilbur C. Anderson

PP: 138

Delicious apple cultures of ‘Supreme Red’ and ‘Wellspur’ incubated in a shoot multiplication medium were etiolated by placing them in darkness under culture room conditions for 2 weeks. Etiolated and non-etiolated cultures were exposed to light culture room conditions for 0, 1, 2. 4, 8, and 16 days regreening prior to reincubation on a rooting medium. The treatments were incubated 3 weeks on this medium before rooting was evaluated. Average rooting percentages from etiolated treatments were 53% for ‘Supreme Red’ and 82% for ‘Wellspur’; from non-etiolated treatments 2% and 10%, respectively. Treatments of 0, 1, and 2 days of regreening resulted in many cultures callusing and subsequent loss of the apical shoot tip.

Author: Rodger A. Duer

PP: 141

Several Juniperus scopulorum cultivars have been grown commercially for many years. These handsome landscape plants, some with striking blue-gray foliage, are used throughout North America as both accent and background plants. Because of their hardiness (Zone 3), they are used quite extensively in the Northern United States and in Canada.

Due to the great difficulty in rooting cuttings of Juniperus scopulorum, most cultivars have traditionally been propagated by grafting. Grafting, of course, is a very expensive means of propagation and, if possible, the rooting of cuttings would be a commercially preferred method. Through several experiments over the years we have learned to root several cultivars with a great degree of success so that many that formerly were grafted are now being produced by cuttings.

Through experimenting with rooting hormone concentrations we have improved the rooting percentages of certain cultivars to a point where it becomes economically feasible to eliminate


Author: John E. Eichelser

PP: 145

In light of the recent, rapid developments in tissue culture, one might wonder why we should still be concerned about improved techniques in rooting rhododendron cuttings. While dozens of rhododendron cultivars are now being successfully produced by tissue culture, there are many more that have not yet been tried, and several that have been tried but without success to date. Among the cultivars that have so far been unsuccessful are the cultivars with indumentum and, at least some of the yellow cultivars, also those with R. fortunei parentage, such as the R. Loderi hybrids (R. fortunei × R. griffithianum).

It is with those cultivars that fall in the above categories that this paper is concerned, such as all the Loderi hybrids, the various Naomi hybrids, and the cultivars with indumentum such as ‘Ken Janeck’, ‘Bureavii’, and R. yakusimanum.

Proper timing, to obtain just the right condition of the wood is even more important with difficult rhododendrons than it is with the rest of the genus.


Author: J.A. English

PP: 147

We have been propagating Acer rubrum for a number of years; however the work done by E.R. Orton of Rutgers University on single node cuttings (Sept. 1978 issue of The Plant Propagator) made large scale propagation practical due to the better utilization of cutting wood.

Our method differs from that in the article, in that we use a potting mix of equal parts sawdust, peat, and pumice, and the cuttings are stuck in three inch square pots. Distributing the roots, by potting from the cutting flat, increases the losses greatly. Out of 20,000 cuttings stuck last year, the rooting percentage after 20 to 25 days averaged 85 percent. The cuttings were taken during July and August, and wood up to ¼ in rooted well. The rooted cuttings are moved to a cold polyhouse where they remain until the following spring. Approximately 50% of these break dormancy and put on new growth before winter dormancy. The balance either die or break into new growth by April first earlier. Our problem is how to make the


Author: H.B. Lagerstedt

PP: 151

Hot callusing is a method used in grafting to expose the graft union to elevated temperatures for a short time to accelerate cell division. Trees to be hot callused usually involve dormant scions grafted to rootstocks that are either bare-root or potted. Hot callusing is often achieved by plunging the grafted tree into warm, moist media, by using a special grafting case (double glass) or by just bringing a potted plant into a warm greenhouse. For limited production, some propagators have placed grafts in barrels of heated media that are placed out-of-doors or in a cool room. The disadvantage of these methods is that the elevated temperatures designed to callus the graft union also cause the scion buds to break dormancy and begin leafing out.

To avoid bud break, propagators have tried grafting and hot callusing in October or November, before the chilling requirement of the scion buds has been satisfied (3). Once callused, the grafted trees are placed in cold storage to satisfy the rest


Author: M.G. Mullins

PP: 162

The use of tissue culture. The technique of plant tissue culture has captured the imagination of the nursery industry, the media, and the general public. To the layman, the use of aseptic methods brings an aura of science and science fiction to the seemingly mundane business of plant propagation. To the nurseryman, the very high multiplication rates which can be achieved in vitro are most attractive from the commercial viewpoint.

Progress in the horticultural applications of plant tissue culture has been spectacular in the last 15 years (9,11). Aseptic methods of vegetative propagation have become standard procedures for production of pathogen-free materials and for the routine multiplication of many high-value ornamentals. A large number of species can now be regenerated in vitro by the induction of somatic embryos or adventitious organs and the technique of micropropagation is assuming special importance in horticulture (6).

The commercial value of aseptic methods for propagation of


Author: Alex Scott

PP: 165

The aim in plant propagation is to achieve a 100% result. All of us, as we have developed our techniques over the years have made many mistakes and learned many lessons. Having learned from these experiences, we have developed skills which make us the efficient operators that we are or should be.

Many of those lessons that we have learned have become basic knowledge to us, but unavailable to others if not recorded or communicated.

In my own case, having started in a very small way, and having built up a business that is supporting 13 people, it is not good enough for propagation knowledge to be directed solely from myself to my propagation staff. In the event of accident, possible hospitalization or even death, that knowledge is suddenly cut off and what was previously a flourishing business, could well get very quickly into trouble.

A few examples of where recorded information is vital, the result of lessons learned over many years, will be discussed. Plants in propagation do have many


Author: Lydiane, Robert M. Kyte

PP: 45

There is an important transition period which tissue cultured plantlets must experience between the protected environment of the laboratory and the harsh world of the greenhouse. In fact, the ability to survive this transition is limiting the commercial use of tissue culture for some species. However, plants of some cultivars survive this crucial stage more easily than others.

Growers know that field-grown plants require good growing conditions: fertile, well-drained soil, proper watering, and nutrients. Tissue-cultured plants also require good growing conditions: controlled environment of heat, light, and chemical nutrients. Between these two very different growing conditions is a transition facility for preparing in vitro-propagated plants for growing on. The requirements for this facility differ according to the cultivar being grown.

This year we propagated 40,000 strawberry plants by tissue culture for growers who sell certified strawberry plants. We grew ‘Hood,’ ‘Benton,’ ‘Olympus,’


Author: Fred Chalker

PP: 168

The far north coast produces over half of Australia's bananas, from a now relatively stable area of about 7000ha. However, there has been rapid expansion in a wide range of other tropical fruits such as avocados, macadamias, custard apple, litchi, guava, papaw, mango and low-chill stone fruits.

Author: Ross J. Worrall

PP: 176

Two types of slow-release resin-coated fertilizers, which control the release rate by coating thickness (Type A) or a release agent (Type B) were tested for their high temperature stability. Heating different formulations (various N-P-K ratios and / or release rates) to 25, 60 or 70°C in water for 30 minutes had little effect on their subsequent release characteristics in water at 25°C for 1 week followed by 45°C for 9 weeks. Two different formulations of each fertilizer type were also held in water for 10 weeks at 25, 30, 35, 40 and 45°C The increase in release rate with increasing temperature was lower for type B fertilizers than type A fertilizers. The percentage cumulative increase in the release rate after 6 weeks of the type A fertilizers between 30 and 35°C was 23% and 16%, and between 35 and 40°C. It was 62% and 60% respectively. For type B fertilizers the increase between 30 and 35°C was 12% and 20%, and between 35 and 40°C it was 23% and 37% respectively.

Author: P B. Goodwin

PP: 181

Why? Potatoes (Solanum tuberosum) are normally propagated as tubers. The use of tubers gives this crop the major advantage of rapid crop development, leading to higher yields in a short period (3 to 4 months from planting) than any other major crop. However, the use of tubers leads to two major problems:
  1. Plants very readily become infected with serious tuber-borne diseases such as leaf roll virus, which are then passed on to subsequent crops. These crops give low yields. The spread of the most serious diseases is via aphids and, for this reason, "seed" tubers are typically produced in areas low in aphids — for example the highland areas of New South Wales. It is also possible to eliminate the most serious virus diseases from individual shoot tips using apical meristem culture.
  2. The second major problem with tubers is slow propagation, normally 7 to 10 fold per year, in field conditions. This severely limits the rate of introduction of new selections, or of apparently virus-freed

Author: Keith H. Macdonald

PP: 183

Our initial soil mix consisted of the following: coarse sand, sandy loam, rice hulls, peat moss. These were spread out in layers and turned four times by hand. This mix was open and dried out quickly, with very little fertilizer added. We then tried a similar mix incorporating sewerage sludge. This mix proved difficult to handle because of the sludge, and fumigation was very difficult. At this time we were fumigating with methyl bromide. We then set about installing a steam generator to pasteurise the medium, at this time we also installed a cement agitator to mix it.

We also switched across to a sawdust mix using three parts red gum sawdust to one part coarse sand. Initially the sawdust used was from heaps 20 to 30 years old. We felt that this sawdust would be sufficiently composted but found that it did tie up nitrogen and plant growth was very slow.

We then began to liquid feed with Aquasol, but the response was negligible. We were then advised to liquid feed with ammonium nitrate.


Author: Gregory P. Lamont

PP: 184

Boronia serrulata is a plant with great horticultural potential but as yet is not widely propagated and grown for amenity horticulture. A study was made into the effects of applied auxin, temperature at the base of the cutting, and source of cutting material on the rooting of cuttings of this Native Rose Response to auxin depended on physiological state and genotype of donor plant. Cuttings selected in the spring (November) from wild donor plants showed improved rooting percentage to applied auxin, however those taken in late summer (February) were unresponsive. Cuttings selected in November from container-grown mother stock plants showed little response to applied IBA up to 8,000 ppm. Basal temperature of 29°C improved rooting percentage in November but in February bottom heat caused drying of cuttings.

wild populations of donor plants gave rooting percentages ranging from 6% to 93% whilst cuttings from mother stock plants showed a rooting percentage of 85%. Although the treatment of cuttings with auxin and the provision of basal heating can promote the rooting of Native Rose, greatest improvement in rooting can be achieved by careful selection and management of mother stock plants.


Author: Gavin A. Wilton

PP: 190

Since we introduced aerated-steaming of soil in our nursery in early 1962 we have gained a lot of experience and have greatly upgraded the equipment. We know the areas for cold spots, the time it takes to bring the various mixes up to temperature, etc , and with this knowledge we set out to automate these operations.

Initially we used electronic equipment for temperature control of the steam-air mix, the sensing of the soil temperature and the timing of the sequences. Unfortunately this equipment proved to be unreliable. When it functioned properly it was very good and, possibly with better equipment and more reliable technicians, this could have been the best way to go. However, after many frustrations over a long period we discarded this equipment and switched to more mechanical type units. The equipment used is available off the shelf from various suppliers. I mention the equipment I have used but do not imply that this is the only or the best equipment available. At least


Author: Kevin R. Gay

PP: 192

Why do we call this system "Plants on Wheels"? We looked at many different ways of moving plants. We looked at using as much productive space as possible and still be able to make the growing area work efficiently. We looked at a pallet system, a moving bench top, conveyor system and the uneconomical fixed bench. None of these were what we wanted in making plants totally mobile all around the nursery. Taking some of the ideas from each of these systems, we made our own design, which is a totally mobile bench.

Author: M.H. Franklin, P.B. Goodwin

PP: 195

The general objective of this research work is to find effective methods of controlling seed borne fungi while maintaining high levels of seed germination and vigour. The material being tested at present is alternaria-infected zinnia seed.

The transmission of fungi by seed is important because it provides an efficient means of dissemination from one place to another and it allows carryover of the fungus in time. Because there is a close association of the fungus and seed there is maximum opportunity for progeny infection and the seed may help protect the fungus from unfavourable environmental conditions. The planting of fungus-carrying seed introduces the disease at random through an area producing well-distributed foci for primary infection (3).

Alternaria zinniae transmission in zinnia seeds occurs when senescent flowers on the plant absorb dew at night and remain wet the next day slowly becoming mouldy from a mixed microflora of fungi including Alternaria zinniae. This Alternaria


Author: Steven A. Dupee, John Clemens

PP: 198

Grevillea species and cultivars were propagated by four different techniques. The results were heavily dependent on the condition of the plant material and on the species or cultivar used. Cuttings of G. × ‘Robyn Gordon’ are best taken from wood 10 to 20 cm from the shoot apex, i.e. not terminal cuttings, and rooted at 29°C without application of IBA. Air layering of G. robusta and G. banksii was 100% successful in autumn but the latter species gave only 44% success in winter under glasshouse conditions. Scions of G. bipinnatifida, G. leucopteris and G. johnsonii were almost 100% successfully grafted onto seedlings of GIvanhoe’ and G. × ‘White Wings’ rootstocks gave 60% success when grafted with G. bipinnatifida scions but the other two scions species were not compatible. Seed germination in Grevillea is promoted by partial removal of the seedcoat and by storage of seed for 2 months at 12°C and 35% relative humidity.

Author: S. Sriskandarajah, M.G. Mullins

PP: 209

Shoots produced by isolated buds of the normally difficult-to-root cultivars, Granny Smith, Jonathan, and Delicious, were induced to form adventitious roots in vitro. Isolated buds from adult trees were cultured in MS medium containing BA (10 µM) to produce proliferating shoot cultures. These shoots were made into microcuttings for induction of roots. The highest rooting percentage (80%) was obtained in ‘Granny Smith’ when microcuttings were grown in continuously agitated liquid culture (half-strength MS) with IBA (10 µM) The most effective culture method for ‘Jonathan’ was growing the microcuttings on filter paper bridges with either NAA (10 µM) or IAA (100 µM) Up to 80% of microcuttings of ‘Delicious’ produced roots when the bases of cuttings were dipped in IBA (750 µM) and grown in liquid medium Exogenous auxin was needed to stimulate root formation in all cultivars. There was a progressive improvement in the rooting of microcuttings with increasing numbers of subcultures. Newly established cultures had a low rooting capacity. After 9 subcultures, 95% of ‘Jonathan’ microcuttings formed roots. With ‘Delicious’ the percent rooting increased from 21% after 4 subcultures to 79% after 31 subcultures.

Author: William A. Smith

PP: 47

Tissue culture at Briggs Nursery has been around for twelve years or more, mainly as a research project and the hope of one man.

There was work done at that time, but until the chemicals and the media were developed, success was minimal. Finally, Dr. Wilbur Anderson, from the Northwest Washington Research and Extension Unit, Mt. Vernon, Washington, was able to start rhododendrons in tissue culture and make them multiply. Afterward, by manipulating chemicals and lights, more and more cultivars were added.

Three years ago our Production Department started to receive plants from the Tissue Culture Department. At first there were only small batches, but the explosion was waiting. In the spring of 1980 we were faced with thousands of tissue culture plantlets to root and grow on.

The first problem we had to face was how to root and grow the new plantlets. The plantlets coming from the test tube were very tender and completely different in character than plant materials normally worked with


Author: K. Rajasekaran, M.G. Mullins

PP: 213

Techniques are described for high-frequency somatic embryo and plantlet formation from (i) cell suspensions derived from nucellar callus of unfertilized ovules, and (ii) somatic cells of cultured anthers. Plantlet regeneration by organogenesis, induction of adventitious buds and adventitious roots, has been achieved in a few genotypes of Vitis and in the Muscadine grape Factors affecting the regenerative competence in vitro of grape tissues include genotype (species, cultivar), growth phase (juvenile or adult), and origin of explants. Competence is a heritable character. Evidence is accumulating that grapevines produced in vitro are variable and that tissue culture per se leads to genetic variation. It is concluded that the future of tissue culture for grape propagation is uncertain but that aseptic methods hold great promise for grape improvement, especially in clonal selection.

Author: Theala H. Petersen

PP: 219

Brough, Petersen Nurseries grow and provide indoor plants, together with a maintenance service, for many business premises in Melbourne and the metropolitan area. For this reason we need a wide range of decorative plants to use under many different and sometimes quite difficult conditions.

Most city offices are closed from Friday to Monday and longer if there is a Monday holiday, leaving many inner offices in total darkness with no natural light whatsoever.

The plants that go into these buildings must be strong and well grown. Unfortunately when these plants are replaced with new ones, those coming out are not as strong and healthy as they were to begin with. These, however, are the plants from which we take the cuttings.

When the old, tired plants are returned to the nursery, they are stripped of their lower leaves and lined up to wait their turn to be cut up for cuttings. I like to leave those that have come from poor conditions for several weeks to give them a chance to firm up and


Author: Robert Kasteel

PP: 220

Two years ago, Jack Paterson — a fellow nurseryman and I discussed the concept of modular greenhouses. We both became very enthusiastic about the many developments we envisaged possible, so here are some of our suggested objectives for such a "modular house".
  1. That the "greenhouse" be of sufficient size to allow for economic nursery operation.
  2. That the "greenhouse" can easily be erected by 2 or 3 persons in a short time.
  3. That the "greenhouse" be made out of light-weight material, simple in construction, and long lasting, with good light transmission.
  4. That the "greenhouse" be well insulated and include a built-in ventilation system.
  5. That the "greenhouse" be of a design which provides sufficient strength to withstand damage from the elements, especially hail.
  6. That under ideal conditions, the "greenhouse" be self-sufficient in terms of energy input required for heating and cooling.

With all these objectives in mind, we looked at them one by one, and also in relationship to each other, and arrived at a structure which we consider meets most of our objectives.


Author: Keith Maxwell

PP: 224


Civilised man has for thousands of years been endeavouring to grow plants in such a manner as to improve yields and quality. The famous Hanging Gardens of Babylon was an early attempt at the culture of plants under artificial conditions.

The early history of soilless culture of plants is closely interwoven with the study of plant physiology. In 1600 a Belgian, Jan Van Helmont grew willow shoots in a protected pot of soil and applied only water. After five years there was practically no loss of weight of the soil and he believed that plants obtain their food only from water. Since then, of course, scientists have shown that plants need 16 elements, these being supplied by gases and soil constituents, as well as by water.

Today there are many horticultural books in which reference is made to the use of soilless medium. The main reasons for such interest in alternatives to soil are that plants in such a manner can be cultured more precisely and irrigation and


Author: Dal Dutch

PP: 231

First let me qualify the term virus-free strawberry plants. This has become an accepted term for strawberry plants (i.e. by commercial strawberry growers) for strawberry plants that have been grown in certified strawberry plant schemes similar to that which exists in New South Wales. In actual fact the plants we propagate should be more correctly described as plants grown from virus-tested mother stocks. The scheme that presently exists in New South Wales is similar to many operating around the world. The principles of virus eradication in the initial instance remain basically the same, however, varying climatic conditions and differences in pest and disease controls necessary for the many environments in which these plants are grown make it necessary for the certifying authorities to vary such rules as isolation, spray programs, and acceptable weed control measures.

The New South Wales scheme has been in existence for ten years and was started as a result of pressure from a


Author: Tony Biggs

PP: 236

Vegetative propagation is very important in the nursery industry, but propagation from seed is the usual method employed by vegetable crop producers. Conventional vegetative methods are used, however, including the use of stem tubers for potato (Solanum tuberosum) and cuttings or division for herbs such as mint (Mentha spp.), thyme (Thymus vulgaris) and rosemary (Rosmarinus officinalis). The advent of micropropagation technology has allowed virus-free clones of rhubarb (Rheum rhabarbarum) to be produced from apical meristems.

Vegetable growers are very well served by their seedsmen and, although seed prices continue to rise, they still form a very small proportion of the total costs of production. Seedsmen are required by law to provide information on minimum percentage germination, and percentage purity. Seed must then conform to these percentages. Bedding plant and flowering pot plant seed may also carry similar guarantees, but it is less likely. Tree and shrub seed rarely has this


Author: A.W. Vink

PP: 240

Horticulture students are instructed in the principles and practices of plant propagation which are employed in commercial nurseries. It will be shown that not only practical aspects of plant propagation but also a thorough knowledge of plants is required to become a proficient plant propagator.

Author: H.C Jackson

PP: 248

Importing mature Dieffenbachia plants from Northern Australia to Victoria was not a profitable operation as the plants arrived in a soft condition and were affected by Rhizoctonia and bacterial leaf spot. So I decided to propagate and grow them myself.

I took tip cuttings from healthy plants, making the cuttings as short as possible, 1½" to 2" of stem, with the leaves about 6" to 9" long. All cuttings were dipped in a solution of 83% Captan fungicide at the rate of 1.25 grams in 10 litres of water. I left the cuttings in the solution for two minutes, stirring them gently to avoid bruising.

Cuttings were then lifted out and left to drain for a few minutes; the cut ends were then dried with paper towelling and dipped in Seradix No. 1 cutting powder with 3% Captan fungicide.

I then put the cuttings into individual 2" tubes using a propagating mixture of 50% perlite and 50% German peat moss. As soon as the cuttings rooted, they were potted into 4" plastic pots, using a very open potting mix,


Author: John Slykerman

PP: 249

Kenny Lane Nurseries specialise in the wholesale production of rhododendrons, camellias, azaleas, conifers, and daphnes. Approximately 10% of the total cutting production is in daphnes. This represents an annual production of 50,000 daphne cuttings per year. Of these 20,000 are grown-on at the nursery and the remainder are distributed to other wholesalers.

The stock plants are grown in a red clay loam soil at the nursery at a spacing of 1 foot between the rows and the plants. This is now thought to be inadequate; ideally the spacing should be 2 ft in each case. The stock plants are fertilized each spring with Nitrophoska "slow release" (15·4·12) which is broadcast around the plants at the rate of 1 kg per 4 square metres. In summer the plants are given a further dressing of sodium nitrate at the same rate.

The first cuttings are normally taken at the beginning of December (early summer) according to their hardness. Most of the cuttings are taken from the tips


Author: Roger K. Ellyard

PP: 251

The effect of indolebutyric acid (IBA) alone and in combination with naphthaleneacetic acid (NAA) and/or 2, 4 dichlorophenoxyacetic acid (2,4-D) on the rooting of P chamaepitys and P pinifolia was investigated The highest percentage rooting was obtained following treatment with a combination of all three auxins. Retreatment of the cuttings with auxin after a period of time under mist further stimulated rooting. A possible explanation for the findings is presented.

Author: A. Bruce Macdonald

PP: 53

The last decade has seen many innovations in the production of hardy nursery stock within the British Isles, many of which have been directed to a number of aspects relating to plant propagation. The objective of this paper is to itemize some of the technical developments that have taken place within the last three years, in addition to those currently being used.

Before looking at some individual topics, it will first be helpful to summarize some of the current trends in British plant propagation:

  1. Nurseries specializing in individual crops, such as Clematis, are developing specialized growing systems — for example, liner production. This has been particularly noticeable with the formation of newer businesses and also in the rationalization that has occurred within some established companies.
  2. The production of crops if Britain that are traditionally imported from abroad, for example, rose rootstock and tree seedling rootstocks.
  3. Techniques to reduce fuel costs in propagation

Author: Ken Dunstan

PP: 256

The genus Tibouchina, which has over 300 recognized species is fascinating, to say the least, with the largest concentration of species in south-eastern Brazil. A secondary grouping can be found in the Andes Mountains from northern Argentina through Bolivia, Peru, Equador, Columbia, through to Venezuela. Some species extend as far north as Mexico.

Over 20 years ago, through the personal efforts and love of the tibouchina plants, they were imported from South America to Australia by Dr. George Hewitt and Mr. Bill Bewley.

Personally, I feel I have been honoured by the help and confidence these two fine men have instilled in me over the past 9 years or so. Consequently I have accepted and carried out the challenge to promote as many tibouchinas as I consider to be of merit for future propagation.

I do this, bearing in mind the importance of ready and popular sales by our retail nursery outlets.

In Alstonville, we have created hybrids from Tibouchina species, and have found many sports.


Author: Doug Wadewitz

PP: 257

This method can be used to propagate several Ficus species such as F. benjamina and F. elastica

Firstly, get an old pair of secateurs and, in the centre of the cutting blade, grind out 5/16" deep by ¾" wide (8 mm deep and 20 mm across) and then sharpen that gap or radius in the blade to the same angle as the original blade. To the inside of the handle end, weld a piece of steel 65 mm long and 40 mm wide and in that piece of steel, put a tapered V, 25 mm wide and 30 mm long, which is serrated similar to a saw-tooth or multi-grip plier's teeth.

Next you need a sheet of aluminum foil similar in thickness and quality to take-a-way trays (difficulty is trying to buy this material from the manufacturers of take-a-way trays; you have to buy 28 lb rolls and months of proving you are not going to be in opposition to them). These rolls come in widths of about 200 mm, so you have to bend and cut them in half, making a sheet 100 mm × 100mm.


Author: Ross J. Worrall

PP: 258

Propamocarb applied at the rate of 0 17 mg per litre of medium every three weeks, stimulated the growth of Pilea cadierei ‘Minima’ apparently in the absence of any phycomycetous fungi, against which it has a narrow spectrum of activity. It however inhibited the growth of the ferns, Thelypteris nymphalis, Polypodium membranifolium, Nephrolepsis exaltata ‘Fluffy Ruffles’ and Pteris tremula, but had no significant effect on the growth of Cyrtonium falcatum or Selaginella kraussiana. There was no interaction between propamocarb and the pH of the medium. The optimum pH for T. nymphalis dry weight was 5 96, frond area 5.97, C. falcatum dry weight 5.98, frond area 6.01, P. membranifolium dry weight 6.41, N. exalata dry weight 6.12, frond area 6.08, P. tremula dry weight 6.11, frond area 6.03, Salaginella dry weight 6.30. The optimum pH for the growth of P. cadierei was equal to or in excess of 6.57.

Author: G.I Moss, R. Dalgleish

PP: 262

Closer spacing of citrus trees, rapid expansion, and a more dynamic situation means that the need is for a cheaper and faster method of propagation. A method is described of producing citrus on a rootstock in containers in less than one year. The work was done with Poncirus trifoliata. It was grown immediately from seed throughout the winter, microbudded, the scion induced to grow and material was ready for early summer planting. This method is compared with another which produced material in one year where the rootstock was grown during the summer and the scion induced to grow during the winter months. This produced better quality trees. The estimated cost of production are presented. Alternative methods, advantages and disadvantages, are discussed in the context of the whole system of citrus production.

Author: Wells A. Eden

PP: 274

There are several different brands and qualities of shade cloth on the Australian market and I have used most of them over the years. It was in late 1978 that the newest type of knitted shade cloth came to my attention and I was quite impressed with its characteristics. These were mainly
  1. The ability of the cloth to be stretched tightly when being fixed to a structure, due to the fact that the fibres are claimed to not be affected by expansion or shrinkage, to any major degree, by weather changes.
  2. The cloth which I used was black and was claimed to have a 2% ultra-violet inhibitor built-in (carbon black) which had shown in accelerated tests to lengthen the life span of the cloth by as much as 20%
  3. Because of the knitted nature of the cloth it can be cut at random in any direction without the cloth laddering or coming unravelled along the edge
  4. The cloth is available in either 6 or 12 foot widths, which gives added advantages on large construction.
  5. The knitted pattern allows

Author: Franz Grossbechler

PP: 276


The tremendous growth rate of the city of Canberra during the sixties and early seventies brought an increased demand for inexpensive eucalyptus seedlings to be used in large landscaping and forward planting projects.

The time-honoured method in which seeds were sown in trays and the seedlings pricked off into another container tied up considerable labour and took six to nine months before the expensive seedlings were ready for planting. This prompted us to perfect a method of direct sowing into inexpensive throw-away polythene tubes packed into reusable wire baskets. Twenty-five tubes fit into a basket of 30 cm × 30 cm.

Handling is reduced to a minimum by direct sowing into the tubes containing the growing medium. By using a balanced soil and nutrient mix we are able to produce 47 species of eucalyptus, (Appendix A) grown to a saleable size in about three months. By using heated glasshouses for the five cold months we can produce four crops each year.

Container. The throw-away


Author: Nev Higgs

PP: 280

Hygiene is one of the most important parts of plant production. It is so easy for us to pick up the phone and order chemicals to cure our ills in the nursery, but I am sure it is much better and cheaper to resolve this before it starts. That is, to look toward prevention rather than cure. This of course falls into basic areas — Why — and — How.

The question of why we should be concerned with plant hygiene is really the first and most important area that any propagator should be concerned with. Without a proper understanding of its necessity by both management and staff, no hygienic programs can be successfully introduced. The key words for this area which relate to the overall topic, are education and awareness.

A good example of the futility of one without the other, happened recently in the nursery. A young lad was taken on just after he had attended a Horticultural Refresher course, a good part of which did emphasize various aspects of hygiene. On this particular day, he had been


Author: Gary R. Eyles

PP: 283

"You'll never change an old field grower to growing in containers."

I have heard that comment made on any number of occasions. It is difficult to change from something you know well and which, in our case, has been a successful practice for over 60 years. This paper is a brief description of how we have begun the change to container growing of citrus.

For many years citrus in the Sydney area has been grown in the field to a stage of one full season's growth after budding. They are then pruned back significantly and dug bare-root. They are sold to orchardists or retailers, in the latter case they need to be placed in a "heeling in" bed, or grown-on in containers for another season and then sold as an "advanced" or three-year-old tree.

A T Eyles and Son were and still are involved in growing the tree to the two-year-old stage in the field. It is now felt, however, that a tree could be grown in a container in two years that would compete favourably with the three-year-old tree containerised after being


Author: JR Gorst, R.A. De Fossard, M. Slaytor

PP: 286

When several auxins were tested individually in the rooting medium of seedling cultures of Eucalyptus ficifolia distinct differences were found in root morphology and were linked to auxin structure. Auxins having a phenolic oxygen between the aromatic ring and the side chain induced callus formation, whereas auxins without this oxygen promoted the development of a good root system. Within this last category, however, different auxins gave rise to distinct root systems.

Several nutrient groups were also tested in a rooting medium containing indole-3-butyric acid (IBA) as the only auxin and there was an interaction between the nutrients and IBA.


Author: Julie A. Plummer, R.A. De Fossard

PP: 295

Following standard disinfestation treatments, cultures of apical and axillary buds of Eriostemon australasius Pers can be initiated on a simple minerals-sucrose-agar medium, i.e. , MZZ [ZM] and rapid multiplication can be induced in cultures transfered to medium — [MHFe,]Z BAP31 6µM [H4+RM] Apically-dominant growth can be induced on transfer of cultures to medium — [MHFe]M KINETIN 10µM [H4+RM], and roots can be induced to form on some cultures on medium — [MHFe] NAA31 6µM BAP0 0316µM[MALL-RM]

Only BAP and PBA were able to induce adventitious bud formation and these cytokinins had, in common, a benzyl ring as a substituent in the N6 position

Interactions of auxins, cytokinins, riboflavin and other growth factors in producing various growth forms in culture are discussed.


Author: John C. Doty

PP: 61

Cedrus deodara and it's grafted cultivars, are well known for beauty and gracefulness. However, they can be a problem, especially at the seedling level.

Usually, every third year is an excellent seed crop, with a moderate to weak crop in the intervening years. Seed can be stored for up to three years if done properly. Most of our seed comes from Italy; but we do collect some locally when a good crop exists. Seedlings from local seed definitely are not as hardy.

Viable seed can usually be determined by a cut test. Greyish or off color radicals is an indication of bad seed. If this situation exists, a germination test is in order. They germinate quite readily on a wet paper towel on the windowsill.

Our first try at seedling growing over 20 years ago was to produce a two-year liner. At transplanting, mortality was high due to the poor root/top ratio and general sensitivity of the plant. It helps to prune branches and do little or no root pruning before transplanting.

The next approach to


Author: Terry Hatch

PP: 306

Lithodoras are hardy sub-shrubs, from southern and western Europe and Morocco. The finest of all the species is Lithodora diffusa (Lithospermum diffusum), one of the most brilliant and widely grown of the genus. It is of a wirey sub-shrubby habit, a strong, rapid trailer, covering itself in early summer with heads of intense, pure, deep blue flowers.

The two cultivars grown in New Zealand and many other parts of the world are Heavenly Blue and Grace Ward. However, sometimes they are hard to propagate in any numbers and to form into well-grown bushy plants.

I have been growing these plants for many years, trying to find an easy way to mass-produced this spectacular rock plant and, like many others who have tried before, never managing to get a good strike. The cuttings often rot when under mist or only send out few thin roots with bottom heat. Semi-hardwood cuttings have never made such progress so I tried very small, soft tips. These seemed to be the best although not all of them rooted.



Author: Denis Hughes

PP: 307

Our nursery is located 20 miles from the nearest rail head, 60 miles from the nearest airport, 100 miles from our main market of any size. Since the loss of our local rail link three years ago some changes have had to be made in our nursery production. In the past it was easy to take our tractors and trailers to the local rail station and consign flower budded plants to the garden centres. Now, without this convenience, we have to do this transporting ourselves. (We find the local trucking firms have no plant sense and our product can arrive in very poor shape when left to them.) With this in mind we have moved away from the production of full-size plants to liners, which are taken to other growing nurseries nearer the population areas. This has also meant a greater interest in new cultivars. These have to be bulked up from very small numbers which may have been imported from other countries, or from friends or acquaintances of single pieces from newly named and registered plants. To

Author: M. Richards

PP: 310

The New Zealand Nursery Research Centre was established in 1975 as a joint venture between New Zealand Nurserymans' Association and Massey University. It owes its origins to a belief, held by the nursery industry, that it would benefit from research into industry problems, carried out in an organization accountable to the industry. This objective was secured by establishing a Research Centre, with an Advisory Committee, to whom the Director is responsible. The Advisory Committee determines policy, and directs the pattern of the research programme.

The role of the Centre can be seen as seeking to investigate problems affecting the nursery industry; these may be known problems, or problems which have not yet been recognized as such. To carry out its work the Centre may enter into co-operative research with other people or organizations, rather than attempt to do all of the work itself. In general it avoids becoming involved in work being undertaken elsewhere, except where it feels that a


Author: Daniel Cohen

PP: 312

Several nurserymen in New Zealand have been breeding Zantedeschia hybrids for a number of years. The golden Calla lily, Z. elliottiana has been crossed with the pink Z. rehmannii. The progeny have been back-crossed to Z. elliottiana and reselected resulting in many potentially useful hybrids. These range in size from plants similar to Z. elliottiana to small miniatures about 30 cm high. Colour of foliage is either spotted or plain green. The spathe is either narrow and pointed like Z. rehmannii or the more rounded form of Z. elliottiana with all stages between. Spathe colour ranges from yellow to orange, red, pink and bronze. Some clones produce few flowers, others many. Selected large flowered clones might be useful for cut flower production whilst some of the miniatures might be suitable for pot plants. There is potential for export of cut flowers or rhizomes of selected clones.

However, in order to test the market for these selections, rapid propagation methods are needed.


Author: Kevin Garnett

PP: 316

Insectivorous plants are, of course, divided into many different genera which are distributed throughout the world.

I will endeavour to show you the differences within the different genera, as well as the propagation and cultural details of these particular plants.


Author: Alan G. Jolliffe

PP: 324

The bromeliad family (Bromeliaceae) is exclusive to the New World — the Americas. Comprising 60 genera and about 1400 species they can be found growing wild in the southern United States, Central America, South America, and various outlying islands. Distribution is through 80° of latitude. Plants are subject to a variety of climatic conditions. Occurring north and south of the equator means plants receive rainfall at different times of the year. This results in widely different life patterns.

Bromeliad habitats range from purely tropical areas to mountain altitudes of 4000m, from sea shore to densely forested areas, and from inland areas to the southern ocean islands.

Climate variation throughout the distribution area has forced the bromeliads to adapt in many ways. Bromeliads have been very versatile in the adaptions.

The world's most well known bromeliad is the pineapple (Ananas), which is grown intensively in Hawaii, Australia, and the Philippines, and exported over the world.


Author: J. Maber

PP: 329

The basic principles of controlled droplet application (CDA) spraying and electrostatic spraying are reviewed, with particular reference to how these techniques can increase the efficiency of spray application.

The introduction of these techniques and their acceptance in New Zealand is discussed.


Author: Roland Clark

PP: 337

Until five years ago, grafted walnut trees could not be bought in New Zealand. No nurseryman could offer them, yet in California alone, there are 200,000 acres of grafted walnuts in orchards, and we were told again and again that they were all grafted outside and there was no special trick about achieving good results.

The breakthrough came when we realised that the limiting factor was our low average temperature, thanks to our equitable maritime climate. Walnuts need a temperature of around 80°F for a period of three weeks to make a strong graft union and as you know, we seldom have a spell of weather as hot as this — thank heavens! California has a Mediterranean climate with moderate winters and very hot summers in the interior valleys, as does southern France where walnuts are grafted in the field as a matter of course. However, walnuts have the ability to callus in winter even though dormant and our grafting methods are based on this.

We like to use two-year-old black walnut


Author: B.E. Sinclair

PP: 340

Here in New Zealand, isolated as we are from the major horticultural areas of the world, new techniques and developments gain acceptance only slowly. New materials for the greenhouse skin are no exception. In recent times, other work (1) has covered the characteristics and operating costs of the alternatives. The aim of this paper is to comment on the current useage of these materials and their applications on the basis of information gleaned from greenhouse builders and growers themselves.

There are certain overlying considerations when choosing a covering and design:

  1. The initial outlay.
  2. The heat conservation properties of the total structure.
  3. Repairs and maintenance, including re-cladding.

To put this another way, the operating costs of the proposed design per unit of area are a major deciding factor. This figure must, however, be balanced against any change in the yield or growth characteristics of the crop in a new environment. The necessity for and the cost of


Author: A.J. Conner, M.B. Thomas

PP: 342

The literature pertinent to the re-establishment of tissue-cultured plants in vivo is reviewed. The difficulties associated with survival and growth of tissue cultured plants after transplantation are attributed to the poor control of water loss from the plants and their necessity to switch from heterotrophic to photoautotrophic nutrition. Aspects discussed include the possibility of transplanting directly from stage II shoot proliferation cultures and rooting in vivo, the importance of stage III culturing for preconditioning plants prior to transplantation, the optimum sizes of propagules and substrate preferences for transplantation, stress reduction, disease prevention, and the importance of humidity, temperature and light levels during transplantation. The relative merits of numerous approaches to transplantation by various workers for many species are discussed. Suggestions of areas in which further work is urgently required are given, along with some recommendations and general guidelines for the re-establishment of tissue cultured plants in vivo.

Author: J.C. Heaman

PP: 63

In British Columbia, where fifty cents in every dollar earned is said to come directly or indirectly from the forest industry, the raw materials for that industry, the trees on the hillsides, represent a truly enormous investment. Farmers and horticulturists have for centuries used both intensive management and genetic improvement to increase their yields, and foresters are now having to apply the same principles and techniques. Intensive management here means using all the tools that are available, which can include choice of the most suitable species, site preparation, control of spacing throughout the life of the crop, possibly fertilization, and use of the best available genetic material. Improvements in the latter will influence all the other techniques and while they must be seen as an integral part of intensive management, they may well be the most important one.

In B.C., about 10 million Douglas fir seedlings are planted each year on the coast and at any time there may be 20 million


Author: Colin G. Knight

PP: 358

Knights Nurseries was established on 16 March, 1968, on the West Coast of New Zealand's South Island in the county of Buller, close to the town of Westport. That a tree and shrub nursery was not established sooner was due, firstly to the heavy rainfall of the area, 2¼ million gallons to the acre, or 8½ ft. at sea level and, secondly, the soils in this area are classed Podzols with a very acid pH of 4.5. However, the development of container-growing overcame this second consideration.

The first requirement was to find a 20 acre block of freehold land. Land that could be drained, close to native subtropical rainforest for shelter as a setting, while still remaining close to the railhead at Westport.

Having found a suitable block of land, we designed a landscape plan of the proposed nursery, aiming for a low maintenance attractive layout. The time to use a bulldozer is before planting trees, so time taken in advance design is well spent.

The next job was to plant shelter and dig drains to


Author: Graeme C. Platt

PP: 360

Transparent and opaque polythene bags are extensively used by nurserymen and plant propagators. We put cutting material in them to keep them fresh, we store seeds and we even sell trees and shrubs nicely packaged in lovely polythene display packages. We also use them for a dozen and one other purposes and take it for granted they are doing the job well. Polythene bags are clean, cheap, don't go soggy, are reasonably tough, and competitively priced. About the only shortcoming transparent and opaque polythene bags have is that they don't do what they are supposed to do, i.e. keep plant material fresh and healthy. In fact, it is hard to find any container more useless for the storage of live plant material. Cutting material collapses, seeds lose viability, flowers wilt, fruit rots, and it all happens better and quicker in polythene bags. Waxed paper, waxed cardboard, wooden boxes, damp sacking, damp cotton, and even tin cans are all superior to polythene for the purpose of keeping plant

Author: Michael Cliff

PP: 366

The President of the G.B. & I Region, Mike Clift, outlined the history of the Rosebowl Award and listed the recipients since it was first awarded.

The Rosebowl is awarded to a member who has made a significant contribution, either to plant propagation or alternatively to the I.P.P.S. in this Region. In presenting the Rosebowl to Brian Humphrey, the President commented that Brian had qualified on both counts. He has a considerable knowledge and experience in all types of plant propagation and has a special interest in some of the newer techniques. He has presented papers of significance to this Region and to the Eastern IPPS Region; he has contributed regularly in discussions in conferences and local meetings. Brian was our first President and, if it wasn't for his drive and enthusiasm in 1968 in inaugurating this region, the I.P.P.S. here might have taken many more years to get established.


Author: Ian Baldwin, John Stanley

PP: 366

"Costings" is a term frequently used by propagators, growers and company directors to express the calculations and procedures necessary to find out one of the most basic questions in nursery production, i.e. "How much does this plant cost me to produce — Could I buy it in cheaper?" The idea of buying in may not be attractive unless the source of material is safe and the producer is reliable. If these two factors are assured then it may, indeed, make good sense to buy in from a specialist propagator and follow the trend that has been seen in glasshouse, field, vegetable, and fruit production during the past ten years.

Such an enormous decision cannot be made without facts — and realistic, factual costs of propagation are extremely difficult to come by from other people and even more challenging to work out one's own. It was to this end that we have tried to produce a logical, systematic schedule for the calculation of the cost of producing a cutting by conventional


Author: Martin J. Hall

PP: 376

We have mist so why use fog? A question often levelled at our Company over the past two seasons since we installed the MEE Fog System at our Sidcup Nursery in an existing wooden glasshouse block of 9,000 square feet.

At a time of uncertainty and financial constraint any capital investment has to be certain of obtaining a quick return on investment. In our case the results obtained by using the fog have surpassed our original expectation.

The use of fog in propagation isn't new and work with Fog Pots in Holland and Switzerland is well documented. Recent engineering technology, much of it derived from N.A.S.A. Space Research, has enabled this system to become a commercial reality.

It should be stressed that this equipment is of a far higher precision than anything so far seen and, as such, needs careful attention in its location, installation, and running.

In the United Kingdom the system is being used for green plants and nursery stock propagation, A.Y.R. chrysanthemum cutting propagation


Author: D.M. Donovan

PP: 381

Where related species grow in geographically adjacent areas, they can often be separated on ecological requirements as well as on morphological characters, and hence remain distinct given stable natural conditions. However, the intervention of mankind creates disturbance on many levels which modifies traditional habitats and may enable otherwise stable plant communities to expand and invade new areas. With taxonomically allied species involved in a dynamic situation, the resulting hybrid populations are not infrequent and generally occupy habitats intermediate between those of the putative parents.

Some native trees and shrubs raised from seed in the nursery may be represented by substantial hybrid populations, with varying significance for the grower and planter. However, the bulk of species raised from seed remain true-to-type, and the incidence of hybridization is far greater in cultivation, whether by chance or design.


Author: Duncan Donald

PP: 384

I should like to explore some of the ways in which members of the IPPS might be able to help with our attempts to save rare plants that might otherwise be lost from cultivation in the British Isles.

Few people would challenge the view that we are, at present, in some danger of losing from our gardens a lot of the species and old cultivars that have been grown in them in the past. This is for a variety of reasons, but most of them hinge on the word ‘economics’. Indeed, sufficient concern was being voiced about this for the Royal Horticultural Society to sponsor a conference on the subject in 1978, the Proceedings of which were reported in an article by C.D. Brickell in the April 1979 issue of "The Garden". The National Council for the Conservation of Plants and Gardens (NCCPG) was formed directly as a result of that Conference and since then has raised sufficient funds to be able to employ me, starting in March this year, to try to co-ordinate its work.

We have two main strategies by which


Author: R.S. Harrison-Murray

PP: 386

The percentage rooting of leafy cuttings of the apple rootstock, M 9, was increased on average from 11% to 78% by prior etiolation. A period of exposure to light before taking pre-etiolated shoots as cuttings was essential and it was not necessary to continue to exclude light from the future rooting zone. The only limitation to the practical application of the technique appears to be that the conditions under the black polythene covers used to exclude light from the stock plants are favourable for Botrytis infection. Because complete darkness is not essential, this problem can probably be overcome by effective ventilation of the covers.

Author: David J. Rowell

PP: 392

Work at East Malling Research Station has shown that the etiolation of stock plants of apple rootstock M9 can result in an increased rooting percentage of softwood cuttings. An observation was carried out to see if there was a similar response on ornamental species, and in 1980 and 1981 a range of species was tested in cooperation with Mr. J. Watts, propagator for Darby Nursery Stock Ltd. Results to date have been variable. In 1980 a number of species, especially lilacs, showed a marked response to etiolation but in 1981 results have been disappointing.

Author: Jonathan Van Der Borgh

PP: 397

We have always been concerned with waste in our business. We have tried to prevent waste of resources where possible, and have used waste products if available.

On our dairy farm, for example, we installed a Retriever unit in 1974. This is a water tank with a copper coil inside which uses the waste heat from the compressors for the refrigerated bulk milk tanks, and uses it to heat 60 gallons of water to 128°F from the ambient temperature of the day. We need water at 150°F to circulate and clean the milking pipelines, so we only have to buy the energy for the additional 22°F required. For an outlay of £740 in 1974, we are saving currently £1,250 a year in fuel costs.

Also on our dairy farm, we use old railway sleepers for silo walls, old motor car tyres to cover the silo sheets, wood shavings for cow bedding and we feed wet brewers grains to the cows as a part of their bulk winter ration.

In 1974 we started our container nursery on an acre of waste land, that is to say, land which was


Author: D.G.W. Edwards

PP: 69

A procedure is described for drying stratified Abies seeds that allows stratified seeds to be safely stored and which promotes higher germination rates. Seeds, dried to a moisture content of 35%, were stored for 12 months without losing the beneficial effect of stratification or without their viability being adversely affected. After certain storage periods, germination of dried seeds was increased well above that in routinely stratified samples. The use of this procedure in nurseries is discussed.

Author: Kelvin Lawrence

PP: 399

Our purpose in going to Spain in December, 1980, was to renew acquaintance with two species of plants which we had previously found growing wild and flowering in mid-winter on the Sierra de Ronda in southwest Spain, inland from Gibraltar. These plants were Clematis cirrhosa and Iris planifolia, both flowering naturally in mid-winter, whose presence would be unsuspected unless you were travelling in that part of Spain in December and January. Both Chris Brickell and Roy Lancaster, who had seen my photographs, thought the Clematis cirrhosa of that region was a particularly good form and well worth introducing into cultivation here if we could bring plants back.

From Le Havre, our first stop in France was at the famous Minier Nurseries near Angers, where we spent two rewarding days. We then pointed the car south towards Spain and crossed the snow-covered Pyrenees by the Somport Pass, 5,000 ft. high. Although this is a "Chaines Obligatoire" pass in winter, we had crossed several times before


Author: David Clark

PP: 401

The chairman of the group, David Clark, opened the discussion by making reference to the paper given by John Stanley and Ian Baldwin, on "Work Flow and Costings in Propagation" which set the scene for our topic.

Brian Morgan then outlined the main points at which cuttings are handled, as follows:

  1. At the stock plant
  2. Collection and storage of cuttings
  3. Compost mixing and preparation of trays
  4. Preparation and insertion (this is the "bottleneck" in the whole system)
  5. Transportation to the propagation unit
  6. Hygiene, e.g. application of fungicides.

Having identified the "bottleneck" as preparation and insertion of cuttings, Brian Morgan, through A.D.A.S. has developed a system which should be applicable to a wide range of nurseries, to speed up these operations. This has led to an increase of between 20% and 50% in increased throughput, to date.

The essential principle involved in the method is that once the cutting is picked up, it is never


Author: Jon Varley

PP: 410

Computers have been in existence for over 50 years, but only within the past five years have they become cheap enough to play a part in the running of small businesses. Computing power that would have required a room full of electronics some ten years ago is now available within a unit no bigger than an electric typewriter. Cost, as well as size, has dropped dramatically, and complete small-business computer systems can be bought for as little as £1500. In the past, only a few large corporations could justify the cost of a computer — usually well over £20,000.

New technology is the key to the changing face of the computer industry — and especially the development eleven years ago of the first microprocessor. By using the descendants of this rather slow and ungainly (in comparison with modern equivalents) device, computer designers have been able to produce small, versatile, and powerful machines which have been dubbed "microcomputers". Such is their popularity in business areas that the new


Author: Paul M. Underhill

PP: 414

This trial, winner of the Student Project Award 1981, was carried out at Hadlow College, Kent.
     Subject:                 Skimmia japonica
     Propagated:          21st October, 1980
     Potted                    2nd February, 1981
     Compost mix         75% Irish moss peat (Medium grade)
                                     25% sand (CaCO3 content above 1%, therefore no ground limestone was added)

Author: Graham Burgess

PP: 417

Aquatics are a very specialised group of plants so first I will describe the natural conditions under which such plants grow. One word, WET. The degree of wetness will vary from moist soil or mud to several metres of fairly clear water.

It is obvious to anyone that there is a marked change in the vegetation at the edges of ponds and lakes. As the soil above the water table becomes shallower the moisture content increases and oxygen levels drop. The first indication is that the only trees that thrive are those that need lower levels of oxygen, e.g. willow, alder, etc. Such vegetation is called "carr" vegetation. The highly variable flora of drier land gives way to sedges, rushes kingcups, and water docks.

Some plants are adapted to grow with their roots rooted below the water. Above the water their aerial stems photosynthesise as normal terrestrial plants. These plants, sometimes half in and half out of the water, are called EMERGENT PLANTS.

As we move further away from the bank and, if


Author: Will Ingwersen

PP: 423

We use modern techniques for alpines where practical but, in some cases, we are going back to some of the older methods of propagation which we find are much more satisfactory from our point of view.

Our nursery is situated near East Grinstead on acid soil and on a very steep north and east slope which suits our alpine plants, and we are sure if they grow with us they will grow anywhere in the country, because we get extreme winter conditions. it is quite normal for us to have several nights in succession of sub-zero temperatures, and occasionally, though we have escaped these past few winters, we get very heavy snow falls. We have been known to welcome the snow, and visitors to the nursery have sometimes been rather astonished to find our staff shovelling snow into our Alpine house to cover the plants, because that's what they are accustomed to in nature. They have a long resting period snugly tucked away under the snow and that is something we cannot offer them very often in this


Author: Geoffrey W.J. Forster

PP: 428

September, 1980, witnessed the second group expedition of several Great Britain and Ireland Region IPPS members to the continent of Europe. Also in the party to Holland and Belgium was a strong contingent of IPPS members and their wives from the various American Regions, who had previously spent some time visiting nurseries and allied institutions in Britain.

As the theme of this year's conference is "The Gateway to The Future", I shall try to confine myself to some of the features that might be considered reasonably "new" to the nursery industry from the continent of Europe and provide some food for thought and ideas later. From the point of view of those members who participated, this will necessarily be something old; however memories may be jogged and it is quite possible that some of the features highlighted will not now be new to several well-established British nurseries.

I will be discussing items of equipment and one or two techniques that may be of value to the nursery industry in


Author: John Gaggini

PP: 430

  1. What action is the Ministry taking to communicate the results of their cutting handling system to the industry?
  2. B. MORGAN: ADAS has been closely involved with ATB on this handling system. We have had a Masters course at which 10 propagators from different nurseries attended and since then they have spread the word. The ATB have already held over 20 courses around the country attended by 130 people, and another 30 courses are planned for the future. The technique has been promoted at major conferences like BGLA and Four Oaks. A video film has also been made for refresher courses showing the hand movements involved in the technique. In addition, a booklet which is a training guide has been produced in conjunction with the ATB. This training guide will have an outline of the times taken to insert a 1000 cuttings of different plant types, i.e. heathers, rhododendron, conifers, and Berberis. Not just one time but a range of times embracing estimates of good, typical, and poor. What ADAS


Author: Alfred J. Fordham

PP: 436

Elliottia racemosa, the Georgia plume, is a small tree or large shrub native to the state of Georgia and southcentral South Carolina. A review of the literature concerning it reveals a history of frustration and disappointment. Despite the fact that it was discovered more than 180 years ago, and despite the fact that its impressive characteristics have often been described, it is still an exceedingly rare plant in cultivation. It has been reported to have lost its ability to produce seeds, to be difficult or impossible to transplant (even in areas where it is native) and to have failed in most propagational efforts. It was also reported that a mycorrhizal association was necessary for the germination of its seeds and the well being of its propagules.

E. racemosa was discovered in the vicinity of Franklin and Hart Counties, Georgia, by William Bartram in 1773 and was later named for Steven Elliot who prepared the "Sketch of Botany of South Carolina and Georgia". For a time E. racemosa was


Author: Leonard Savella

PP: 440

Propagation of Picea pungens ‘Glauca’ and other cultivars by grafting has been a successful method at Bald Hill Nurseries for many years. When grafting spruce we like to use 2 year old wood which gives us a large scion and a sizeable graft when completed.

When preparing the scions for grafting, around the first of February, we thought how nice it would be if we could root the healthy, well budded, lateral cuttings we were removing from the scion.

We decided that nothing would be lost if we tried, so we stuck approximately 200 cuttings in three different rooting media using several hormone powder combinations. By the end of May, three of the cuttings rooted. This was a success to me because I am a great believer that if you can get one to root the others should root, if taken at the proper time.

In June, when we were sticking our summer outdoor mist cuttings I found the key. I decided that when we finished sticking our dwarf Alberta spruce cuttings that I would stick the different


Author: Ralph Shugert

PP: 78

It is a distinct pleasure to share with you some seedling production techniques which I have observed, and indeed practiced, over the years. All of these observations will be geographically from Nebraska east to the Atlantic Ocean.

Assuming this is your first venture into the sexual propagation of plants, spend some time on researching the topic. Every volume in the Proceedings of our Society gives us several articles on seed propagation. In Volume 29, there were two splendid articles, one by Tom Wood (3) (GB & I Region) and one by Hugh Steavenson (2) (Eastern Region), both presented at the Western Region meeting in 1979 at Sacramento, California.

One can go back to the first meeting of the Society in 1951, and read Dick Fillmore's (1) words on this topic. After a review of IPPS papers, then purchase this book. "Seeds Of Woody Plants In The United States," Agriculture Handbook #450, Supt. of Documents, US Printing Office, Washington, DC 20402 (cost $13.60). This book covers seed data


Author: Richard A. Jaynes

PP: 442

There is an implication in the title of this panel that parallels a common misconception on the "ah ha!" theory of solving a problem or making a discovery. I suggest that the process is usually a gradual and evolving one rather than a sudden revelation. There is an analogy, for instance, with the "discovery" of a new cultivar. It generally takes 15–25 years to get a new cultivar to market, so, when do we say it is new? Was it when the cross was first made or when the plant was first selected? To the horticulturist or nurseryman neither event may be remarkable for it may be several years later before he is certain that the cross or selection is truly unique. Even then his excitement may be tempered until he is certain the plant can be propagated and he sees how it is received in the market place. Likewise, timing of when a problem is solved may be as difficult to pinpoint as to say when a discovery was made.

The problem I confronted was vegetative propagation of


Author: James S. Wells

PP: 445

When I came to this country in late 1946 I was aware that cuttings of hybrid rhododendrons were being rooted experimentally in Boskoop, Holland. What was still to be proved was the value of the method as a commercial procedure, and, most important, how would plants propagated in this way develop as they matured? The information from Boskoop was therefore obtained and held as a matter of interest, but was not considered to be of immediate practical importance.

In the winter of 1946 we grafted 35,000 rhododendrons onto Rhododendron ponticum understocks and these were planted out the following spring. The early summer of 1947 was hot, wet, and humid with the result that catastrophic losses were sustained in not only the new batch of grafts but also more mature plants. Clearly something had to be done. Discussions with other growers indicated that plants of R. ‘Roseum Elegans’ produced by layering were apparently more resistant to the wilt disease than were similar plants grafted onto R.


Author: James R. Clark

PP: 449

The phenomenon of juvenility is well-known to plant propagators, in that it plays a critical role in the propagation of a number of woody plant species. And while this phenomenon presents a major developmental process in plants, little is known about its precise nature, or about the level of control that plant propagators may exert over the maturation state of a given plant.

In order to examine juvenility and its relationship to propagation, some definitions must be made:
     Juvenile — that stage in the life cycle of a woody plant during which flowers cannot be induced to form
     Adult/mature — that stage in the development of a woody plant during which flowering may occur
     Transition — that period between the adult and juvenile phases during which flowering may be initiated by the normal flower inductive treatments
     Phase change/maturation — the process that controls the development of the juvenile form into the adult

In all of these definitions, the sole basis of differentiation is flowering. In


Author: Calvin Chong

PP: 453

Cuttings of Acer saccharum, Cotoneaster acutifolius, Malus pumila ‘Mor Spur McIntosh’, Malus ‘Hopa’, and Taxus cuspidata were treated (5-second dip) with 0 (control), 1,250, 2,500, 5,000, 10,000, 20,000, and 40,000 ppm indolebutyric acid (IBA) dissolved in alcohol, rooted under intermittent mist, and evaluated for percentage rooting, mean root length and mean root number. Cotoneaster acutifolius, Malus ‘Hopa’, and Taxus cuspidata showed significant increases (P = 0 01) in rooting percentage, root length, and root number, with optimum responses in these parameters observed with IBA treatments between 10,000 and 40,000 pp. Acer saccharum showed a significant increase (P = 0 05) only in rooting percentage with maximum response occurring with the 5,000 ppm IBA treatment. Malus pumila ‘Mor Spur McIntosh’ failed to root regardless of IBA treatment.

Author: Dale M. Maronek, James W. Hendrix, Jennifer M. Kiernan

PP: 461

During the past few years, there has been a growing interest in mycorrhizal research. There are many reports citing the possible benefits mycorrhizal fungi may afford nursery crops, such as increased nutrient uptake, growth, disease resistance, cold hardiness, drought tolerance, rooting of cuttings, and fertilizer conservation. Information pertaining to these benefits has been thoroughly discussed in previous Proceedings (8,19,20) as well as for other horticultural and forestry crops (25,47).

A major requirement in developing uses for mycorrhizal fungi in the nursery industry will be to determine cost-efficient methods of producing plants infected with specific mycorrhizal fungi and no others. We feel that one of the most efficient methods of producing mycorrhizal plants will be through the inoculation of seedlings at time of propagation. During propagation, the amount of mycorrhizal inoculum required is minimal, and regulation of environmental conditions and/or cultural practices can


Author: Michael A. Dirr

PP: 472

A review of the pertinent literature shows that numerous chemical compounds have been tested for root-promoting activity. It is estimated that well over 10,000 chemicals show positive formative effects (17). The essence of chemical plant propagation began in 1934 with the discovery of a naturally occurring auxin, indole-3-acetic acid (IAA) (15). The demonstration that two synthetic (do not occur in higher plants) auxins, indole-3-butyric acid (IBA) and naphthaleneacetic acid (NAA), induce a greater rooting response was shown by Zimmerman and Wilcoxon in 1935 (21). In 1937, Zimmerman and Hitchcock published a paper (20) showing the comparative effectiveness of the acids, esters and salts of IAA, IBA and NAA in rooting cuttings and other growth responses. The essence of their work is described throughout this paper. I heartily recommend that nurserymen secure copies of these papers for their files.

Modern plant propagation revolves around the use of IBA, NAA, and their derivatives. Both


Author: Blair Mastbaum

PP: 479

Labor costs in America have steadily increased while worker productivity has in many cases declined. The survival of our businesses depends largely on our ability to increase efficiency. Labor costs comprise approximately 60% of my total budget. Coupled with decreasing worker productivity I feel this is the first and most logical place to work on becoming more efficient.

We begin by taking an unbiased look at our operation. Are the facilities efficient? Is everyone producing an equal amount and is the amount enough? Assuming the facilities and procedures are efficient and the goals are in order then the area to concentrate on is labor efficiency. What amount of production can we reasonably expect from our workers? I think one answer lies in the use of production standards. A production standard is a tool used to measure the performance of a worker against premeasured production expectancies.

Production standards help us not only in gauging the productivity of employees but in many other


Author: Arthur J. Oslach

PP: 482

The passive solar principle in greenhouse construction is to utilize solar energy in its most economical and efficient form. The basic concept that we used had to be:
  1. Of simple construction,
  2. Economically feasible for commercial greenhouse production,
  3. Reliable and efficient.

Therefore, a system was developed that employed a solar collector, a water storage system, and a simple form of passive energy transport. This system, when compared to an active solar system, is very inexpensive to construct and requires very little maintenance.


Author: David C. Leach

PP: 488

My goal in breeding ornamental plants has been to produce hybrids which can make it commercially. Some hybridizers make crosses for their own satisfaction; some do it as a joint activity with other hobbyists. But mine is a full-time occupation and I have hoped to produce new rhododendrons for very cold climates that would be profitable for commercial growers and present no problems in production. The records show that the most cold-hardy rhododendrons are also usually the most heat-tolerant, so I am always hoping that some of my hybrids will be equally useful in the south, and some of them have proved to be so.

The rhododendron cultivar ‘Roseum Elegansrsquo; is still the best seller in the northeastern United States. It was introduced in England by Anthony Waterer some time before 1851. It's a dirty magenta-pink and it grows far too large for contemporary houses and gardens. But it's hardy and it roots easily. It's one of the group of so-called "ironclads" which means that it can be grown at


Author: Raymond J. Evison

PP: 495

It is fairly unusual for a business to be set up around an entire genus. Normally, a person who is interested in a specific genus will specialize in one section, especially if that person is a nurseryman — he will produce the best selling species or cultivars from that genus. If a person is a private collector then usually that person becomes a fanatic specialist If a botanist becomes involved in a genus, he too, specialises, usually, along a fairly narrow pathway.

What I am about to describe to you is the way in which our company has collected many different clematis species and cultivars and the way in which a concept is being carried out: that concept is a mixture of the specialist collector, the plantsman, the nurseryman, and also with the businessman's view to making money What we have tried to do is combine all of these different angles the fascination of collecting, successful cultivation, and the mass production and modern selling techniques.

During the last 25 years, clematis