Volume 26

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Author: William J. Libby

PP: 27

The traditional uses of forests have been as watershed protection, as habitat for game and other wildlife, for firewood, for lumber, and for that special spiritual renewal that many people find in the presence of trees. As the human population continues to require more resources, some of these traditional forest uses are being increased and we have returned to others, sometimes in non-traditional ways. For instance, wood alcohol may replace cordwood as transportable energy, and generators fueled by wood waste already feed electricity into our transmission lines. Plywood, laminated and end-glued products from tennis rackets to stadium beams, chipboards, particle boards, and fiberboards, have joined traditional sawn boards and timbers in many old and new uses. The demand for paper and paper products continues to increase and expand. And wood chemists can create plastics from dissolving pulps, food flavors from terpenes, and perhaps soon, food itself from enzymatically degraded

Author: Barrie Coate

PP: 85

Procedures which we use to produce what we feel are some of the highest quality eucalyptus trees grown in containers are as follows:

The first step is to obtain the highest possible quality fresh seed, wherever possible from isolated seed trees of superior characteristics for a given species.

The second step is to plant the seeds in rows 1" apart in screen-bottomed seed flats filled with a mixture of 30% coarse peat moss and 70% coarse perlite — from mid-February through June. After the seed is sown, it is covered with fine screened sand to provide a dry, open a medium around the germinating seeds. Germinating requires one to two weeks.

These screen-bottomed flats provide a labor-free root pruning when the root-tip gets the open air, thus encouraging many lateral roots, which do not require much root pruning during transplanting to liners.

They are standard 18" × 18" × 2" wood flats with no bottom boards. We attach 1/8" galvanized hardware cloth to them to form a bottom, with 1" × 1"


Author: Hildegard Sander

PP: 86

Although it seems easier to understand the life cycle of a flowering plant, it is most fascinating to observe, to learn, and to understand the life cycle of a fern. If I plant 10,000 seeds I can expect 7 to 9 thousand seedlings. If I plant the same number of spores I will feel quite happy to count later 2 to 3 thousand sporophytes.

What is the difference between a spore and a seed? A seed is an embryo (a fertilized egg) surrounded by nutritious tissue which will feed the embryo, and a capsule to protect the embryo. A sore is an asexual cell, unfertilized (no embryo) and containing no nutritious tissue. A seed grows immediately into a plant under the right circumstances. A spore, being asexual, will have to be placed under very exact conditions to develop first into a "stage in between", called the prothallium. Proper conditions are: the right amount of water, light, and a certain temperature. Without these three elements spores may remain dormant but keeping their capacity for


Author: Robert M. Boddy

PP: 87

Container growing of rhododendrons on the northern California coast is nearly identical to conventional California nursery operations in southern and northern California interior valleys. At Fort Bragg, however, we have very cool summers, and therein lies the key element of our effort to produce a commercial crop of container-grown rhododendrons.

In addition to cool summers, winters are relatively mild. Minimum temperatures drop to about 22°F., and we have occasional snow flurries, but neither the cold nor the snow is really severe or long lasting. Thus we do not have the problems of Eastern growers of container plants in having to provide winter protection. And the cool summers are certainly an advantage, almost to the point of being an absolute requirement. We have attempted to grow container rhododendrons in southern California, but experienced nothing but trouble from the warm sun burning the foliage, to extensive infections of root fungus diseases caused by excessively warm soil in the containers.


Author: C.I. Lee, J.L. Paul, W.P. Hackett

PP: 95

Rooting of stem cuttings of Bouganvillea, Ceratonia siliqua, Chrysanthemum morifolium, Euonymus japonica, Euphorbia pulcherrima, Hedera helix. Trachelospermum jasminoides, sp., Juglans hindsii, Pistacia chinensis and Salix laevigata is greatly promoted by dipping in H2SO4 prior to applying indolebutyric acid. On the other hand, NaOH treatment results in considerable increase of rooting of cuttings of azalea, Bougainvillea sp., Liquidambar styraciflua, Osmanthus heterophyllus and Pinus radiata.

Author: Glenn A. Goldsmith

PP: 100

There is a small group of companies, about 6 in the U.S. and perhaps 15 worldwide, that have caused a gardening revolution during the last 20 years. This revolution is the change by the gardening public from the sowing of seed in the garden to the purchasing and planting of started plants. The companies largely responsible for this revolution are those developing F1 hybrid annual flowers.

It is not a coincidence that the rapid development of the bedding plant industry coincides with the tremendous increase in the use of the F1 method for the production of flower seed. In fact, neither industry could have developed to the extent they have without the other. The bedding plant industry needed and has used the greatly improved cultivars in order to have a superior product which the public would buy, and the seed companies needed the professional grower who had the experience and facilities to grow the expensive seeds.

Hybrid flowers offer the same advantages over open-pollinated sorts


Author: Paul Picton

PP: 107

Large nurseries producing batches of plants by the thousands and plush garden centres, where one has to thread a delicate path through concrete and plastic paraphernalia before finding the plants, are as remote from my kind of nursery as is a Texas ranch from a Herefordshire smallholding. I don't feel in the least envious (I suppose some might call it ambitious); in fact, I consider myself lucky to be running the sort of tiny concern which relies upon the production of interesting plants for it's survival. Perhaps, we can, quite easily, grow 100 plants of Anchusa caespitosa and several hundred Romneya coulteri. But it is equally as satisfying to get out annual crop of 10 plants of Sanguinaria canadensis ‘Plena’.

So many of our plants provide just the odd few cuttings or the occasional crop of seed. It is worthwhile asking the question "Would there by any point in producing such plants in quantity, even if it were possible?" True enough, a certain element of the gardening public will


Author: B.H. Howard

PP: 113

Fruit research stations repeatedly have to rapidly increase small quantities of new plant material for wider testing under commercial growing conditions. Those cultivars which meet exacting current day standards must then be rapidly multiplied so that they can be supplied to commercial nurseries specialising in elite stock propagation in sufficient quantity to justify the expense of setting up new production beds, often in isolation from existing material.

Very limited quantities of material are initially available when originally virus-infected clones are made "virus-free" by heat therapy which provides, in the first instance, one meristem to start the new clone. In the case of a newly bred cultivar, the original plant is often supplemented by others during the early screening procedures for disease resistance and propagation ability, but initially few plants are available.

Scion cultivars. A simple approach can be used for a new cultivar destined to become a scion cultivar because fruit


Author: Richard Flint

PP: 116

There would appear to be as many ways of producing any particular plant in the U.S. as there are in G.B. However, due to the higher summer temperatures throughout the U.S., there is a much greater tendency to propagate in the open or under-shade with the aid of mist. Only a very small percentage of plants are being grafted as a means of propagating some of the more difficult items, or where rapid reproduction is required. For example, a large proportion of the ferns are grown by this method. Frequent pruning and the selection of even batches of cuttings produce high quality saleable plants.

In the Sacramento Valley, California, I saw peaches, plums and almonds being produced on seedling understocks. The seed was sown in the autumn. During the following spring the seed germinated and by June had produced a pencil-thick stem. It was budded at this time after reducing the understock somewhat. Two weeks after budding, the understock is further reduced. By autumn the bud will have


Author: Derek Wade

PP: 117

  1. The physiology of growth control
  2. The types of chemicals with growth regulatory activity
  3. Experiences with chemical control of flowering pot plants:
    1. Height retardation
    2. Production of cuttings
  4. Experiences with chemical control of nursery stock:
    1. Plant shaping
  5. The commercial potential of growth regulator chemicals on ornamentals.

A. THE PHYSIOLOGY OF GROWTH CONTROL. The continuing advancement in the knowledge of the physiology and biochemistry of growth and developmental processes in the plant is enabling the plant scientist to explore the potential of chemical growth control with more purpose and precision and to evaluate the many biologically active compounds produced by the agricultural chemical industry. Such chemicals function by supplementing, inhibiting or interacting with the naturally occurring (endogenous) plant growth hormones. The hormone systems control not only developmental processes in plants such as germination, dormancy, flowering, and


Author: J.G.D. Lamb

PP: 127

Hamamelis species can be rooted from cuttings in high numbers but losses in the young plants can be heavy during the first winter. Trials indicate the importance of taking cuttings early, inducing good growth, and avoiding high fertility levels in growing on composts. H. vernalis promises to be easier to propagate than H. virginiana and to be compatible as an understock for H. mollis.

Author: Richard Van Klaveren

PP: 32

In late September 1961, the Strybing Arboretum, San Francisco, sent us a group of seedling Mahonia plants raised from M. lomariifolia seeds. These were grown for a year or so in the cold frames, then transferred to the lathhouse as they increased in size. When this last move was made one plant seemed to have a very different leaf from the rest and we speculated that it might be a hybrid, perhaps with M. bealei since the shape of the leaflets suggested that species. Our suspicions of its mixed parentage were strengthened in December 1964 when a drop in temperature to 11°F, and continued below-freezing conditions for several days reduced all its sister seedlings to brown pulp, but left in nearly untouched.

When this plant first flowered in late December 1967, we made a careful analysis of it and felt that we were correct in assuming the parentage to be M. lomariifolia × M. bealei. In order to be more certain we sent an inquiry to Strybing Arboretum to find if M. bealei or some other Mahonia


Author: H.J. Welch

PP: 130

Turning first to the selection of dwarf conifers by the purchaser:- My experience at flower shows is that, (having disposed of queries as to whether my dwarf conifers are bonsai, or house plants, or ferns; or even, on one occasion, cacti) the first serious question raised by visitors always is "How big will it grow"?

This is so basic to the production and sale of dwarf conifers that it is a matter on which I feel we, as nurserymen, should be able and willing to give the public much clearer guidance than we sometimes do. First and foremost we must endeavour to put over the fact that there is no simple answer to this apparently simple question; the concept of "ultimate size" just does not apply to plants which continue to grow throughout their long lives. Although the term "Dwarf Conifers" is too well established ever to be ousted from the language, one fact I believe we must get across is that they would be more accurately described as "slow-growing conifers" in that they are dwarf


Author: Douglas Anderson

PP: 136

In 1962 Darby Nursery Stock Limited, started to establish a wholesale production unit specializing in container grown shrubs and conifers. Before this date, the company was concerned with the production of certified soft fruit stocks, mainly strawberry plants, blackcurrant bushes and raspberry canes for commercial fruitgrowers.

It soon became apparent that large quantities of propagation material were needed and, at that time, unrooted cuttings of deciduous shrubs were not easy to obtain from trade sources although rooted conifer cuttings and, to a limited extent, unrooted cuttings could be obtained mainly from the continent.

It was decided to plant up stock beds to ensure a good supply of cutting material. It should be pointed out that no ornamental field-grown stock was produced, which might have yielded suitable material.

We already had some 20 years experience in the establishment and maintenance of blackcurrant stoolbeds, for the production of hardwood cuttings.

In this


Author: Denis Fordham

PP: 139

The subject of raising trees from seed is rather a lengthy one, I therefore, intend to talk about production generally rather than about one particular crop or plant with reference to the methods being used at Oakover, producing seedlings in raised seed beds covered with grit.

Before raising plants from seed one might ask oneself, what are we trying to achieve? This is the key question, the answer to this is to produce plants that will fulfill the market's requirements, i.e. large one-year plants suitable for stocks or wide lining, for containerization, or for close lining to produce a 1 + 1 seedling. Since all the requirements for these purposes are different it is no good using the same method of growing to try to achieve this, it does not work; e.g. Acer platanoides seed sown in early March at about 200 per square yard will produce a large seedling at the end of the season as compared with sowing much later at a greater density, producing more smaller plants per square yard. This


Author: Claire F. Howe

PP: 145

The purpose of this paper is to outline the work carried out in two group projects during our third year as students in the Ordinary National Diploma in Horticulture at Hadlow College. Besides benefitting our practical skills, our two main objectives were, firstly, to assess the suitability of the subsequent trees for garden centre sales after a one season's growing from winter bench grafting; secondly, to see how a range of genera, species and cultivars respond by being grown on under protection.

Author: Chris Lane

PP: 150

Why propagate Norway maple by grafting and not by the accepted practice of field budding?
  1. because of poor bud takes in the field, due to spring planting and sometimes the poor quality of stocks available
  2. to fit in with cropping programme on the nursery (i.e. at Oakover we are seed sowing or potting container plants at critical times for the field production)
  3. labour profile, i.e. (because we have peaks at planting and budding time, it is convenient to graft these in the winter)
  4. to produce a well-grown maiden whip of good size for field lining (i.e. 5–7')
  5. to be able to line out in the field at 100% crop

Author: Michael Clift

PP: 153

There are at the outset two major subdivisions to be considered; (1) production under protected cropping — whether it be glass, polythene or woven materials and (2) in the open.

Protected cropping. Possibly the advent of the woven materials gives cause for optimism. The growing environment on a hot day for humans, at least, is more agreeable than under polythene and it is reasonable to believe the plants, too, are under less stress and also that growth would be less drawn. These materials also offer a slight amount more protection from frost damage than does polythene. Polythene with it's very quick temperature build up, particularly in the early months of the year, constantly causes anxious moments when slow-release fertilizers are incorporated in the compost. To alleviate these risks, either a reduced rate of fertilizer is added to the compost, or it is eliminated entirely, depending only on regular liquid feeding. Glass can be ventilated, as can a newer type of polythene structure,


Author: B.H. Howard

PP: 155

Small maiden trees of Comice/Quince C, Cox/Malling 9, Victoria/St. Julien A, Crimson King/Acer platanoides, Tilia × euchlora/T. platyphyllos and Ulmus × vegeta Commelin/U. glabra were raised in one season under glass by chip budding newly-potted stocks in spring. The main limitation to this method of quickly producing trees suitable for sale, for example, to garden centres, appears to be poor establishment of the rootstocks, particularly noticeable in imported seedling material, which may have been partially desiccated during an extended period of dispatch.

Author: A.G. Biggs

PP: 158

We can consider outdoor vegetable and protected crop plant raising under two main headings — vegetative methods and propagation from seed.

Vegetative Methods.Not many temperate vegetables are propagated vegetatively under commercial conditions — notable exceptions being rhubarb, asparagus, artichokes and, of course, potatoes. On the other hand, many of the important glasshouse ornamental plants are propagated in this way; chrysanthemums, carnations, poinsettias, alstroemerias and all the bulbs are good examples. In all instances the propagators pay great attention to the following points:

  1. Virus eliminationusing heat treatment, meristem culture and, subsequently, mother plant maintenance
  2. .
  3. Clonal performance indexing
  4. Production of uniform propagules (cuttings/bulbs) by rapid multiplication techniques.
  5. Provision of production and crop programming advice for their customers.

Certainly points 1 to 3 also apply in the case of rhubarb and potatoes where the production of


Author: Kingsley Bungard

PP: 165

THE NEED. The title I shall discuss is concerned with training, an integral part of the management function in a business. If the training function is to be effective, it must be based on the needs of the company and industry. This conference has highlighted some excellent examples of needs justifying planned training and these new techniques and information have to be transferred to those who are paid to apply them.

The examples of training need include —

  1. New propagation techniques
  2. New information concerning growth regulants
  3. The new entrant and casual worker who frequently enter a business with little or no related skill
  4. The member of staff already employed whose output/quality of work is not quite in line with the company's standards. For instance, budding rates and percentage take can vary quite dramatically within a gang of staff working in the same field.

As a Training Board, we have evidence that a three-day training course can very quickly improve the rate of


Author: D.C. Harris

PP: 169

Several earlier papers presented at IPPS conferences concerning the propagation of Japanese maples have specifically described propagation by cuttings or winter grafting. At Exbury we propagate by summer grafting so a summary of our technique may help to complete the overall picture.

Understocks. Two-year seedlings of Acer palmatum are potted into 8 cm rigid plastic pots during the dormant season and stood, pot thick in a cold frame or on a protected open bed until required for moving under glass. Towards late spring or just after new growth has started to appear the plants are cut back to 40–50 cm in order to facilitate handling at time of grafting. If this early pruning is overlooked the tops of the understocks can be cut back later in the year but it has been observed that late cutting shortly before grafting can severely reduce the foliar area at a critical time and weaken the plants. During mid- to late-June the potted understocks are transferred to a well-ventilated glasshouse


Author: Edward V. Clark

PP: 35

In the last few years there has been a marked increase in the hobby of gardening throughout the United States. Seed companies, garden supply houses and canning jar producers, and we, as nurserymen, can attest to this increased activity. As nurserymen we are in line to cash in on this trend in many ways. Many of us produce or sell fruit trees and grapevines and other related items for this market. It may well be, however, that we are overlooking some items on which a good return can be made. Here at L.E. Cooke Co., we grow several items besides trees and vines that would be of interest to the home gardener, such as horseradish, artichokes, berry vines, Jerusalem artichokes, rhubarb and asparagus. When I tell you what is involved with two of these crops, rhubarb and asparagus, you may see a place for them in your operation.

Planting. In the past we have planted these two crops in the spring and in the fall; both dates have their advantage and disadvantages. Fall sowing of the seed allows


Author: Charles Scheer

PP: 173

Propagation of taxus at Half Hollow Nursery has been evolving from all heated glasshouse propagation to the use of some minimum-heat plastic houses — groundbed propagation. We produce from 50 to 80,000 yews each year.

Cuttings are generally taken sometime after the third frost in the fall. We start with Taxus cuspidata ‘Densiformis’, which we sell the most of as a finished plant. Cuttings are made 8 inches long, cut on the top and bottom, with the lower half stripped of needles. After sizing, the cuttings are bundled about 50 per bundle held with a rubber band. Bundle bases are dipped in straight Chloromone which is held on a sponge in a shallow pan. We had been using Hormodin #3 powder but have found chloromone dip faster and more effective.

Cuttings are stuck in washed coarse sand. The addition of 40 to 50% perlite has been tried on a small scale and seems to be even better. Cuttings are stuck in the heated house from November to January with an air temperature of 60° to 65°F and with


Author: James E. Sabo

PP: 174

In looking for a simpler and more economical method of propagating taxus cuttings, we turned to ground beds in quonset type poly structures.

Author: Gerald Verkade

PP: 177

Two-year liners are the main-stay of our business so we root about 600,000 taxus yearly. We root in both glass and plastic-covered greenhouses. Our glasshouses use conventional hot water bottom heat but the plastic use forced hot air. In the glasshouses we use a 5" deep medium of 1/3 perlite, 2/3 coarse sand. The medium is used 3 to 4 years by using 2% formaldehyde drench.

The plastic houses are 21' &times 96'. The cuttings are stuck in 4' &times 4' pallets with side boards at a depth of 5" coarse sand and plastic burlap under the medium. We have found that the air space between the ground and the medium helps maintain a 60°F rooting temperature.

November to December is the time to make all taxus cuttings to obtain rooting with the least top growth. The cuttings are taken from 2 to 20 year old plants and placed in cold storage to be made up. They are all made up in handful bunches and cut to 8" in length with clippers. They are then stripped of needles 2½" from the bottom and quick-dipped in 3


Author: Joseph P. Von Kornya

PP: 178

We start our cuttings in the fall after 2 to 4 killing frosts. The spreading types we make 6" long, the uprights 8", using the current year's growth. The cuttings, depending on cultivar, are treated with Hormo Root B (15% thiram, 0.40% IBA). For hard-to-root kinds we use Hormo Root C (15% thiram, 0.80% IBA). Easy cultivars are Taxus cuspidata ‘Densiformis’, T. cuspidata ‘Compacta’, and T. ‘Green Mountain’. The harder ones are Taxus × media ‘Wardii’, T. × media ‘Hicksii’, T. × media ‘Hatfieldii’, T. brevifolia ‘Nana’, our patented T. ‘L.C. Bobbink’, a globe-shaped taxus, and the only real troublemaker, is T. baccata ‘Repandens’.

All cuttings are stuck in pure perlite about 1½" to 2" deep. Spacing is ½" × 2". The medium is kept at 65° to 68°F. I believe bottom heat is very important. The cuttings are lightly syringed 2 to 3 times a day to maintain high humidity in the greenhouses. They are dusted with Captan every 2 weeks, especially for damping-off. We have found that it is best to


Author: Betsy Scarborough

PP: 180

The nursery market is becoming increasingly competitive and the emphasis in production is to produce better quality plants. To improve quality the optimum growth conditions for each crop must be investigated. By manipulating microenvironments, those alterations resulting in positive growth responses can be selected and incorporated into the production system.

In our quest for improved quality one factor, medium, has received intensive study. Our standard production medium was a peat:sand mix, 3:2 (v/v) for ericaceous plants and 1:1 (v/v) for hollies, roses, junipers, euonymus, cotoneaster, and metasequoia. Our initial tests centered around the introduction of hardwood bark into the medium.

Through our experiments with hardwood bark as a medium component we hoped to answer several questions.

  1. Were hardwood bark mixes superior to peat:sand?
  2. What effect did particle size of the bark have on plant growth?
  3. Was peat a necessary component in our hardwood bark mix?

Author: Ezequiel Collazo

PP: 183

The story of present day miniature roses in the United States has been created mostly by two men: the late John de Vink of Boskoop, Holland, and the late Robert Pyle of The Conard-Pyle Co., West Grove, Pennsylvania. When Mr. Pyle was in Europe in 1933 he visited Mr. de Vink in Holland and found him experimenting with the breeding of miniature roses for his own amusement. Mr. Pyle was charmed with the idea of having "Fairy Roses", as he thought of them, and was sure they would be popular if he could produce them on a commercial scale. This would also permit Mr. de Vink to afford to keep amusing himself by developing more, and better, cultivars.

The miniature rose is a newcomer to the West. Miniature roses were known in England early in the 19th century. It is believed that the plants were a form of Rosa chinensis ‘Minima’ found by traders in the Far East, and brought in from China or Japan, where they had been dwarfed by patient oriental art. This little rose, known as Rosa pusilla (Rosa humilis)


Author: R.W. Henley, R.T. Poole, C.A. Conover

PP: 185

Chlorosis and necrosis of plant foliage is caused by various agents including: disease causing organisms, insects, mites, nematodes, high soil salinity and air pollutants. Occasionally, foliar problems cannot be directly attributed to these causes. Such is the case with certain plants which respond to excessive fluoride ions in irrigation water, soil solution or fertilizer. As recently as 1971 (5), the necrotic lesions which often develop on the distal portion of leaves of Cordyline terminalis propagated from terminal cuttings was reported to be of a nonpathogenic nature. Research findings at that point indicated that Cordyline could be propagated best if cuttings were stuck in either calcined clay (Turface) or Louisiana sedge peat, in preference to other available rooting media.

The first report of fluoride toxicity in tropical foliage plants was made by Conover and Poole (1) in late 1971. Freshly harvested cuttings of Cordyline terminalis ‘Baby Doll’ developed necrotic lesions primarily on


Author: Elton M. Smith

PP: 190

Leaf analysis, a well established diagnostic tool, should be used by the nursery industry, along with soil analysis, to diagnose suspected nutritional disorders, detect deficiencies prior to visual manifestation and, most important, to monitor the mineral status of plants during the growing season. Sufficient values are listed for 12 elements as a guideline for fertilizer determinations.

Author: Harold E. Stoner

PP: 193

In 1974, Dr. Francis Gouin introduced to this Society, the possibilities of using composted sludge in container growing mixes. His talk aroused my interest enough, that upon returning home, we immediately procured 40 tons of digested sludge from one of the Baltimore waste-water treatment plants. We composted this material using 2 parts aged hardwood bark and 1 part digested sludge. After composting thru the months of January, February, and March, using a front-end loader to turn the pile, a test was taken. The result were: pH 5.6, magnesium 300+ (V.H.), phosphate 510 (V.H.), potash 258 (H), soluble salts 3200 ppm (hot).

We consulted with Dr. Gouin, and a decision was made to add soil to reduce the soluble salts to a safe level. We used a half compost and half top soil mix for planting 500 shade and flowering trees in baskets. When the planting was completed, they were heeled-in with a hardwood bark mulch and top-dressed with nitrogen. There was not much different at first from our


Author: Francis R. Gouin

PP: 195

Nurserymen sell tons of top-soil with balled and burlapped crops and hundreds of cubic yards of potting mix with plants grown in containers. Peat moss, shredded bark, and green-manure crops have been their primary sources of organic matter, while fertilizers and lime have been their principal sources of plant nutrients. As prices for these materials increase and supplies of peat moss and bark decline, the need for new sources of organic matter and plant nutrients is evident.

Sewage sludge when properly composted with wood chips (1,6) makes an ideal substitute for peat moss as a soil amendment (3) and in potting mixes (5). This dependable source of organic matter, once a public liability, can now be converted into a community asset through composting. Compost made from sewage sludge and wood chips is similar in appearance to a potting mixture of peat moss and pine bark with an odor nearly identical to garden compost. Safe disposal of sewage sludge continues to be an environmental problem,


Author: Donald S. Croxton

PP: 37

Hortica Gardens is a small mail order nursery selling, primarily, material to be used for bonsai training. All plants are container grown. Generally some preliminary pinching and pruning is done to make them more acceptable as bonsai subjects.

Two popular plants for bonsai training are Chinese elm (Ulmus parvifolia) and Catlin Elm (Ulmus parvifolia ‘Catlin’). Although elms are often propagated by seed, it is more convenient to root cuttings. For the ‘Catlin’ elm, of course, vegetative propagation is necessary to insure identity of a true cultivar.

Chinese elm cuttings are made in spring and summer. Usually the cuttings are 7.5 to 15 cm long. The bottom two or three leaves are removed, leaving a minimum of 5 leaves at the top. ("three leaf" cuttings will root, however) Cuttings are made from new shoots when they are 15 to 30 cm long. Longer shoots may be made into two or three cuttings. If the tip growth is very soft, it's best to cut it off, since it will probably wilt and die back in


Author: Brian Dykeman

PP: 201

Optimum temperatures for rooting of cutting have long been accepted to be in the range of 20 to 25°C. Many studies have been carried out to support this assumption (2,5). However most studies on rooting temperatures have involved only one evaluation — that of root development after a set time period. Few studies have actually looked at root initiation and root development as two separate plant processes. Likewise, few workers have noted the time required for root initiation at different temperatures and actual root numbers initiated at different temperatures.

Hartmann and Kester (2) state that 21°–27°C day and 15°C night is optimum for most plant species. Below 21°C rooting is reduced and slowed down. At temperatures of 23° –27°C root inhibition often occurs as well as root injury. Howard (4) has shown that easily-rooted plum cutting root best at 20°C. However, he noted that shy-rooting clones root more readily at 25°C.

A few workers throughout the last 50 years have looked at root


Author: Michael A. Dirr, David J. Williams

PP: 208

Nutrition of ornamental crops is a complex problem. For example, Brewer (2) reported containerized Ilex crenata growth was maximized with 400 ppm N, 15 ppm P, and 120 ppm K in the irrigation water. Gouin and Link (7) reported growth of containerized Taxus × media ‘Hatfieldii’ was maximized at 224 ppm N, 75 ppm P, and 135 ppm K. Plant materials grown in nursery operations are diverse, the nutritional factors which result in growth maximization of one plant type often do not produce equivalent results with others.

Leibig in 1843, developed what has become known as the "Law of the Minimum." The law states that, if any essential element is deficient with all others at optimum levels, growth is controlled by the deficient element. This premise holds for any essential component of the cultural system (light, water, temperature, pH, drainage). Thus growers may be employing similar nutritional practices yet obtaining different growth results because other cultural factors are limiting.

Response from


Author: George L. Staby

PP: 211

Hypobaric or low pressure storage (LPS) is a relatively new technology that may significantly alter many production and/or marketing procedures presently being used in horticulture. It is the purpose of this paper to briefly introduce LPS by discussing the history, principles, capabilities and present status of this technology.

History. The storage of horticultural commodities and other perishables is limited by pathological and/or physiological disorders. Of concern is the influence of carbon dioxide, ethylene and other gases on commodity longevity. For example, it has been well documented that ethylene can promote many detrimental processes that can reduce commodity usefulness (5).

Studying fruit storage in 1965, Burg and Burg (8) observed that if gas exchange (i.e. CO2, ethylene) from within the fruits to the atmosphere was enhanced, storage longevity increased. Expanding this concept, Burg and his associates developed LPS and have had two U.S. patents issued (4,10). After


Author: Barry A. Eisenberg, George L. Staby, Thomas A. Fretz, Terry R. E

PP: 215

Unrooted and rooted geranium (Pelargonium × hortorum L.H. Bailey.) cuttings were stored for 2, 4 and 6 weeks utilizing a low pressure (LP) storage system maintained at 2.2°C. Unrooted cuttings stored at 1/30 atm were of acceptable quality after 2, 4 or 6 weeks of storage and rooted equaled cuttings directly rooted without storage. Rooted cuttings removed after 2 and 4 weeks of LP storage were acceptable while similar material removed from common cold (CC) storage were unacceptable. In all cases LP storage extended the life of rooted and unrooted geraniums when compared to CC storage.

Author: William Flemer III

PP: 220

Mr. William Flemer III served as moderator for the new plant forum.

Dr. Elwin Orton of Rutgers University showed slides of five hollies which he has developed. These are being introduced to the trade as Ilex ‘Green Dragon’, I. ‘Dwarf Pagoda’, I. ‘Harvest Red’, I. ‘Autumn Glow’ and I. ‘Jersey Princess’. Andy Knauer showed slides and discussed Idesia polycarpa. Jim Wells showed slides of Magnolia ‘Leonard Messel’, deciduous azaleas, Rhododendron ‘Pink William’, R. ‘Peachy Keen’, unnamed seedling designated as R. WS 1, R. ‘Gillian's Gold’, R. ‘Windsor Daybreak’, R. ‘Windsor Buttercup’, R. ‘Vivacious’ and a fragrant R. ‘Clear Yellow’ which he's currently increasing. Dr. Gus Mehlquist showed slides of his rhododendron breeding research aimed at developing a white and a red rhododendron. Mr. Flemer finished the plant forum with slides of trumpet flowers Campsis × tagliabuana ‘Mme. Galen’ and Campsis ‘Crimson Trumpet’, a fragrant double flowered wisteria, a sugar maple, Acer saccharum ‘Bonfire’, Aesculus pavia ‘Splendens’, and two new


Author: Walter F. Grampp

PP: 220

When we decided to go into azalea production the first thing we did was to acquire good stock plants. They were fairly large plants, 4 to 5 ft in height. These were planted in well-prepared beds and were heavily mulched with pine bark. They were then cut back hard and left alone for two growing season.

Immediately after flowering the plants were dead-headed which seems to hasten shoot development. When the new shoots were 4 to 6" long and slightly firm, cuttings were made. Normally, this is from May 1 to June 15. We have both cut and stripped them and it doesn't seem to make any difference. However we did try to leave a stub to encourage future branching.

The cuttings are dipped into a solution of Vapor Guard, Sevin and Captan as described by Larry Carville when he spoke to us in Mobile in 1967. We use two pails, one for the dip and one to drain the cuttings, which are then packed into plastic bags for storage in a cooler. We feel it is good


Author: John R. Havis

PP: 222

Internal leaf flooding is caused by movement of excessive water into leaves by root pressure while transpiration is inhibited by high relative humidity. Experimental evidence indicated that neither the flooded condition, nor freezing alone cause leaf injury. Flooded leaves were somewhat less cold hardy than normal leaves. Holding at low temperatures for 20 hours or more caused much more injury to both normal and flooded leaves than freezing for 2 hours. Tests of leaves sampled in February revealed a wide variation in cold hardiness among cultivars and among plants of the same cultivar in the field and in storage. Suggestions are given for clearing leaves of internal flooding and for preventing injury associated with flooding.

Author: James E. Cross

PP: 228

Calluna and Erica present different ornamental qualities from most other plants with which we work. There are many species of Erica, only four of which are hardy in northern climates and one of these, E. cinerea, is marginal. Calluna vulgaris, typically called heather, has provided over 200 named cultivars in a variety of color, texture, and form not seen elsewhere in a single species. Those who took the Plant Propagator's trip to England in 1973 will well remember this diversity.

Within their relatively dwarf stature, growth habits vary from distinctly upright to completely prostrate. Flower colors include clear white, near reds, a clear pink and all shades of rose and lavender. Flowering time is unbelievably diverse. On Long Island we have blooms in the garden in every month of the year except May. Textures vary greatly but probably the most pronounced characteristic, particularly of Calluna vulgaris is its extremely wide range of foliage colors. They offer unlimited potential for


Author: Richard Jaynes

PP: 233

Mountain laurel, Kalmia latifolia, is slow in growing from seed to flower and clonal propagation is difficult. As a consequence, demand for common mountain laurel exceeds supply and most of the special flower and foliage selections are either unavailable or expensive.

Selection and breeding studies in recent years have focused attention on the diverse kinds of mountain laurel. These include: red-budded, banded, pink, or white-flowered types; selections with petaled flowers, and some with willow-like leaves or miniature habit. The genetic diversity, clonal selections, culture, and propagation techniques were recently reviewed in a book (3). Laurel propagation has also been discussed by Jaynes (2), Eichelser (1), and Radder (4) in the Proceedings of the International Plant Propagations' Society.


Author: David R. Mears, William J. Roberts

PP: 237

Research on the engineering aspects of greenhouses at Rutgers has been primarily oriented to the development of structures which are functional, low cost and energy conserving. In the last few years energy conservation has been the highest priority goal and research has begun on alternative energy sources.

The crop requirements and the weather patterns at the greenhouse location are primary factors to be considered. The structure and its control systems must work together to provide the crop requirements under the prevailing weather conditions at a reasonable cost.


Author: R.M. Warner, R.L. Fox

PP: 38

Planting material ("seed&quot) of ‘Williams hybrid’ (‘Giant Cavendish’) was grown rapidly from frequent irrigation and nitrogen applications, using vigorous sword suckers, trimmed and heat-treated to control burrowing nematode (Radopholus similes). Within 12 months each corm had produced 4 to 6 clean well-developed sword suckers.

Bananas grown with high levels of nitrogen produced more and heavier bunches. Production peaks were compared at low, medium and high nitrogen rates.

Growth rates were greatest from May through October when solar energy averaged 424 gram cal./cm2/day and mean maximum-minimum temperatures were 28.5°C (83.4°F) and 22.8°C (73°F) respectively. Growth rates were lower from November through April when solar energy was 257 gram cal./cm2/day and maximum-minimum temperatures were 26°C (79°F) and 18°C (66.9°F). Rainfall of about 1300 mm (42") was supplemented by low-head sprinkler irrigation. Nitrogen, solar energy, and available water appeared to be the most critical factors under Hawaii conditions in banana production.


Author: J.H. Tinga

PP: 246

My freshman economics teacher said, "There is no such thing as a free lunch." That also applies to the cost of heating propagation houses. My emphasis is: How can we decrease the cost of fossil fuel? Oil and gas and heat-making stoves were relatively cheap 10 years ago and we learned to enjoy their great convenience. Sometimes the cost was so low that we tried to heat up all outdoors. Some of you probably own a stainless steel infra-red heater that was advertised as keeping the frost off an acre of ground. But the cost of oil, gas, electricity, heaters and fin pipe have all gone up.

There are other heat sources that we ought to look into. One is earth heat — the heat in the soil — 6 — 10 — 100 ft deep. Heat pumps in our homes use earth heat. I believe that our poly structures should be designed as an "A" shape with perhaps a 30° rafter angle right down to the soil. You may not store many plants in that narrow angle, but your structure at night is picking up earth heat from that covered


Author: Ted H. Short, Warren L. Roller, Phillip C. Badger

PP: 249

Greenhouses are heated almost entirely by solar energy by day and fossil fuel by night. It is the fossil fuel requirement at night that is becoming or has become prohibitively costly. The greenhouse almost always accumulates surplus heat during daylight hours — even in Ohio mid-winters. A system that collects solar energy and stores greenhouse surplus heat for night-time use could be very beneficial. Therefore, a solar pond is being studied as a solar collector and potential storage system along with the appropriate equipment to move heat to and from the greenhouse.

Natural solar ponds were first discovered in the early 1900's in Hungary (2). Temperatures up to 80°C (176°F) have been recorded. It is theorized that such ponds are fed by saltwater springs while fresh rainwater periodically flushes off the surface. The result is a stable pond of solar heated brine at the bottom of which is too dense to circulate to the surface and cool. More recently, researchers believe that a warm


Author: Ben Davis II

PP: 253

For many years we have been producing apricot, fruiting plum, and ornamental plum by T-budding on peach seedling rootstock. At no time have we been satisfied with the results. We have also tried T-budding on various plum rootstocks, mainly Prunus americana, with even worse results. About 2 years ago we had a block of Prunus americana on which the bud stand was so bad that we decided to graft them in the spring where they stood in the field. This was highly successful but also expensive. This success caused us to wonder if bench grafting might be a more economical way to produce these trees.

In January, 1975, we bench-grafted 7,169 apricot and plum scions on Prunus americana rootstock. The scions were dormant, one year growth. The grafting method used was whip and tongue, made at the crown of each seedling rootstock. The graft unions were wrapped with standard cloth grafting tape. The grafts were callused in the greenhouse for 10 days at about 65°F. After the callusing period the grafts were held in cold


Author: Steven M. Still

PP: 255

This paper combines information compiled from the extensive research of Dr. Fenton Larsen of Washington State University, my own recent defoliation study, and a recent survey of nurserymen concerned with the problems and present uses of defoliants.

Late leaf retention has plagued the nursery industry since storage of fall-dug stock began. This problem results in delayed digging and increased labor to hand-strip or "sweat" the leaves off. Heating of foliage in storage causes stem and bud damage and a possible increase in storage molds which can cause losses.

Leaves can be removed by mechanical or chemical means. The most common mechanical methods are hand-stripping and sweating in pits, both of which are expensive. This paper will discuss chemical defoliation.

A good chemical defoliant requires the following: at least 50% defoliation in a short time (2-3 weeks); inexpensive and easy application; and, most important to the nurseryman, not be injurious to treated plants. However, use of


Author: Ray E. Halward

PP: 259

We have been propagating lilacs extensively since 1967 and due to the generosity of botanical gardens, arboreta, and park areas supplying propagating material, we now have one of the largest collections in the world and are the official registration authority for the International Lilac Society for lilac cultivars. We are aiming for a complete collection and any new additions would be most welcome. Stocking the collection to where it is today gave me the opportunity to try a great many species and cultivars. I have found lilacs to be consistent performers as far as rooting is concerned, the overall average of rooting during those years being 75–100%.

Timing. I have taken lilac cuttings from early June after flowering until July 26th in quantity, and have found even at this late date 70% rooting was obtained. In most cases we prefer to take our cuttings from the last week in June until the second week in July. Cuttings with mature leaves are much easier to handle. We have had


Author: H. A. J. Hoitink, H. A. Poole

PP: 261

During the last decade composted hardwood tree bark has partially or completely replaced peat in nursery potting media in the Midwest. One striking effect of this change has been the disappearance of various types of root diseases. With ericaceous plants, which are very susceptible to Phytophthora and Pythium root rots, significant increases in growth have been obtained in mixes consisting largely of composted bark rather than peat. Recently, research at the Ohio Agricultural Research and Development Center has focused on the basic mechanisms underlying this suppression of root diseases. It has been found that composting, with frequent turning of stacks (once every 2 weeks), eradicates plant pathogens. The temperature of compost stacks reaches 120° to 160°F for a period of 6 to 12 weeks, depending on the type of bark being composted. Pine bark generally requires 1 lb actual N per cubic yard, to avoid nitrogen deficiency on plants subsequently produced in the mix. Fresh hardwood bark

Author: J. Stanley

PP: 264

The Surrey nursery industry produces about 12% of the total of hardy nursery stock produced in the United Kingdom. It is an area of mainly small wholesale growers situated to the Southwest of London.

Author: Mark Cunningham

PP: 267

What does tissue culture really mean to the propagator? Tissue culture is a procedure in which an excised plant part is placed on an appropriate sterile culture medium, managed under controlled laboratory conditions, grown in a special disease-free environmental, and ultimately develops into a new plant.

In starting a tissue culture laboratory, there should be sound objectives to justify the expense of setting up the costly facility and delegating trained personnel for its year 'round operation. Also, one must set up goals and reasons for operating the laboratory. Two important reasons for investing time and money into this type of project are:

  1. Recovery of Disease-free plants. This is probably the most important reason for getting into tissue culture. By removing virus, bacterial and fungus pathogens which invade the plants, chances are vastly greater in restoring the plant or cultivar to its normal vigor and state of productivity. I must point out that by tissue culturing a plant, we

Author: Charles W. Heuser, John Harker

PP: 269

The Liliaceae is composed of many herbaceous perennial plants. It includes lilies, iris and other commercially important ornamentals. One flowering ornamental group, the Hemerocallis, known in the trade as daylilies, have been popular as herbaceous perennials for many years. The standard method of propagation is through division (1,2,4,6). This procedure, while it yields plants that are true-to-type, is a slow method of asexual propagation. The slow nature of propagation by division results in the better new cultivars never reaching the commercial market but remaining in collector and breeder gardens. We now describe a tissue culture method for rapid clonal multiplication of daylilies. When properly employed, the method yields uniform plants without genetic deviation.

Author: Mark R. Zilis, Martin M. Meyer

PP: 272

The germination and development of embryos in vitro on a defined medium is one of the oldest techniques of in vitro culture of plants for propagation purposes. Embryo culture was first shown to have promise for rudimentary embryos of orchid when Knudson (3) developed a nonsymbiotic method of germinating orchid seeds on a sterile medium. Up to that time, orchid seeds were germinated in conjunction with a fungus which gave a very low percentage of plants.

Plant breeders, particularly of fruit trees, were some of the early advocates of test-tube culture of plant embryos. They found that some crosses, which normally did not set seeds due to embryo abortion, would produce seedlings if the embryo was excised and grown in vitro. Tukey (7) made considerable use of this technique and developed media for fruit tree embryos. Lammerts (4) produced dramatic increases in the breeding programs of fruit trees, camellias, and roses using embryo culture.

A recent development in embryo culture utilizes


Author: Carlton S. Koehler

PP: 48

Biological control has been given a rather restrictive definition by some entomologists, who maintain that it applies only to the use of parasites, predators, and pathogens for the reduction of pest populations to tolerable levels. Others have chosen to expand its definition to include other technologies of a biological nature directed toward pest population reduction. I have followed the latter course.

As plant propagators, biological control has very little to offer you directly. Its greatest utility, based on knowledge to date, comes after the plants you have propagated are planted in the landscape, orchard, vineyard, or other growing site. Yet as plant propagators you properly have an interest in the kinds of pests which attack the crops you produce, the intensity of resultant damage, and the procedures necessary to alleviate pest infestations.

Parasites, Predators, and Pathogens. Our most important parasites are tiny wasps and flies whose adults deposit their eggs in or on pest


Author: Paul E. Read, Paiboolya Gavinlertvatana

PP: 275


Culture of organs, tissues, single cells and protoplasts has been used to solve many problems including improving propagation time and increasing clones, developing new clones, growth regulator and physiological studies and producing disease-free clones. In our laboratory these techniques have been used for reduction of time for propagation, increasing clones, physiological and growth regulator effects and plant improvement of asparagus and freesia; in addition, separating chimeras and protoplast culture are being studied on dahlias. This paper is a preliminary report of our findings, techniques and of investigation underway, together with a brief review of research in tissue culture.

Asparagus: We will discuss asparagus tissue culture in some detail because its development has elements common to tissue culture in many species. Asparagus is a dioecious plant. The yield varies between sexes, male and female plants being


Author: Harold H. Smith

PP: 286

Cell-fusion hybrids were obtained by fusing protoplasts of Nicotiana glauca and N. langsdorffii in the presence of polyethylene glycol. The hybrid protoplasts were selected out of a mixed population by growing on a culture medium that does not support the growth of parental protoplasts. The cell fusion hybrids had chromosome numbers that were higher (56 to 64) than in the amphiploid (2n = 42). Most of these "hyper-aneuploids" were fertile and their progeny retained the characteristic morphology and approximate chromosome number of their hybrid parent.

Author: August E. Kehr

PP: 292

Plant tissue and cell culture techniques have advanced to the stage where their application to commercial plant propagation is imminent, and in quite a number of cases, is in actual practice. The purpose of this paper is to review some of these techniques and point out their potential practical value for plant propagators and others. These techniques include opportunities for: 1) rapid plant multiplication; 2) eradication of viruses and other tissue-borne pathogens from "old" cultivars; 3) production of homozygous lines; 4) long-time storage of germplasm; 5) transfer of genetic information with isolated DNA, and 6) more efficient plant breeding. Somatic hybridization of protoplasts to develop parasexual plant hybrids has been discussed by Dr. Smith, and the use of shoot-tip culture for plant propagation has been covered by Mark Cunningham.

Author: Alfred J. Fordham

PP: 296


In August, 1973, I was part of the delegation of I.P.P.S. members from the United States that attended the Sixth Annual Meeting of the I.P.P.S. Region of Great Britain and Ireland. During the technical sessions held at Berkshire College of Education, G.V. Purcell of L.R. Russell, Ltd., Windlesham, Surrey, presented a paper pertaining to the budding of Hamamelis. In the discussion that followed we learned that in Britain propagation is by budding and grafting, using Hamamelis virginiana as understock. We also learned that seeds and seedlings are becoming unavailable in Britain and there was much concern about the future propagation of Hamamelis. Actually there is no problem, for experience at the Arnold Arboretum with 22 taxa indicates that all Hamamelis can be rooted from cuttings which can then be induced to survive the first winter.

In recent years many new cultivars of Hamamelis selected and named in Europe have been imported by the Arnold


Author: Ted Richardson

PP: 301

Rhododendron Farm is a small family operated nursery. The husband and wife owners started producing rhododendrons in 1963. The original unit was a greenhouse liner operation. In 1968 this was sold and container growing of larger plants was taken up. About 2½ acres are utilized in Mountain Home, N.C. for finishing off 3 gal plants. The greenhouse liner production was replaced with an out-of-door operation in southern Florida utilizing about ½ acre. Attempts to maximize growth have resulted in the production of many cultivars of hybrid rhododendrons to a 15" to 18" size in 15 months from the time the cuttings are taken from the stock plant, and 24" to 30" plants in 27 months. The owners have performed all laborious jobs, except occasional day labor for potting and loading and unloading, until 8 months ago when one skilled person was hired full time to share in the confinement and the long hours require of the business.

Climate. Mountain Home is located near Asheville, N.C., in the Blue


Author: Ralph Shugert, William Snyder

PP: 304

The Question Box Session was convened at 8:15 p.m. immediately following the annual banquet. Mr. Ralph Shugert and Dr. William Snyder served as moderators.

MODERATOR SNYDER: Ben Davis, have you tried grafting peach cultivars onto Prunus besseyi or P. tomentosa?

BEN DAVIS: The paper I presented dealt with producing standard trees but we have used P. bessey as a dwarfing rootstock. We have never tried grafting them; we T-bud them but when we used P. tomentosa we had very poor results so we now T-bud only on P. besseyi

MODERATOR SNYDER: Were the bench grafts you made done by hand or machine?

BEN DAVIS: We bought one of those grafting machines and so we made them both ways; I had a count made but after looking at the figures I'm not sure they're correct. This year we made about 25% of our apple grafts on the machine and, as a rough figure, we got about 25 to 30% take as compared to 50 to 60% by hand grafting. We were saving


Author: Robert L. Baker

PP: 310

Over the centuries Japanese horticulturists have developed an extraordinary number of cultivars and training techniques which are unfamiliar to American gardeners. In the spring of 1974 I spent several months in Japan visiting gardens, nurseries, botanic gardens, and natural areas in an effort to familiarize myself with the native and cultivated flora.

There are several nursery areas where unusual plants may be seen in abundance. Angyo, a few miles north of Tokyo, is one of the major centers. In this district may be found a great many small specialty nurseries, some of which may occupy ½ acre or less. Although in some cases the stock plants may be grown directly in the ground, more often all plants are grown in ornamental containers of varying size. Usually they have been carefully pruned and shaped as specimen plants. Most of these rare dwarf, contorted, or variegated plants will continue to be grown in this way when they leave the nursery. If they are used in the landscape, they may


Author: E. Stroombeek

PP: 313

The title for this short presentation is posed as a question and instead of singling out just fungicides I would like to broaden the scope and ask the question, "Horticultural chemical allergies, or worse?"

In our meetings of the 1950's and '60's, we were constantly reminded to use fungicides like Captan, Phaltan, Phygon and Terraclor in preventive spray-programs in our propagation. What was the attitude of the average grower or propagator to these relatively new materials? We were supposed to be very cautious, read the labels carefully and follow all the instructions we were given conscientiously.

But did we really do all those things? Thinking back to my experiences as a propagator in Lake County, I have to admit that I, as well as most of the growers that I knew and met, were rather casual and even lax when it came to spraying. After all, the labels were often not too specific as far as warnings for dangerous consequences were concerned. And word of mouth in our area was that


Author: Judith L. Shirley

PP: 315

The development and maintenance of the aquatic garden at the U.S. National Arboretum, Washington, D.C. is discussed as a general guide for the management of small pools. Information is given on the culture and vegetative propagation of hardy and tropical water-lilies, lotus, and other aquatic plants. Methods for the control of algae and insect pests are also described. The aquatic plants grown in the pool in the 1976 season are listed.

Author: George R. McVey

PP: 322

Methylene urea reaction products and certain experimental nitrogen sources varying in water solubility were evaluated under a wide range of environmental conditions using woody ornamentals as the indicator plant. Phytotoxicity was dramatically reduced by decreasing the water solubility of the nitrogen sources. Maximum safety and plant growth from methylene urea products was realized with 50 percent of the nitrogen in a cold water soluble form. In the midwest and northeast (Hardiness Zones 3, 4 and 5), a residual of 4 to 6 months was realized with a 3 to 4 month residual in more moderate climates (California). Experimental nitrogen sources exhibited better residual and safety than methylene urea products. This was particularly evident in moderate climates (California) with the trend still evident in the cooler climate of the midwest and northeast. A 12 to 18 month residual was realized with certain experimental nitrogen sources.

Author: Kenneth F. Baker

PP: 52

Growers have become increasingly interested in soil treatment and in pathogen-free stock as they have realized that the ultimate sources of disease organisms are the soil (including water and nonliving organic matter) and living plants. Soil treatment may be accomplished by chemical fumigation or by steam. Destruction of microorganisms has been the objective of such treatments since they started in 1880–90, and recommendations have emphasized overkill rather than minimal effective dosage. There is now a marked trend toward minimal treatments and toward fumigants selectively toxic to pathogens so as to avoid creating a biological vacuum dangerously subject to reinvasion by pathogens, and so as to decrease formation of toxins injurious to plants.

Commercial soil steaming to control diseases and insects was begun in 1893, but the methods remained empirical for 60 years, with little scientific study or grower inventiveness. Critical investigations were published in England, Norway, and


Author: D. Cohen, P.M. Le Gal

PP: 330

A method for the rapid propagation of Daphne × burkwoodii is described involving meristem-tip culture, shoot proliferation, root initiation and transfer of plants to potting medium. The place of this method in a clean stock programme is described and results with Daphne odora are compared.

Author: Fred Ruhl

PP: 334

I don't wish to go into details of spore culture because every fern grower will have his own method, but everyone will also have experienced, to a greater or lesser extent, losses due to environmental fluctuations. From my experience I have devised a completely self-contained, controlled environment which ensured consistent and favourable results.

The "Contraption" as I call it, is made entirely from glass and resembles a miniature glass house. A conventional 150 watt aquarium heater and thermostat provide the heat and control. The size is determined by the dimension of the trays used. My unit is designed to accommodate two plastic seed trays and is constructed from ¼ inch plate glass, the front being 10 inches high, back 15 inches high, by 40 inches long and 14 inches wide. The glass should be bought cut to size and glued together to form a tank. Small pieces of glass are glued to the middle of the bottom to form a cradle on which the heater is horizontally placed. A half-inch hole


Author: A. Maloy

PP: 335

As there are innumerable methods of grafting and each person has his (her) own preference, I will limit myself to the ones that I have used with some success.

Side Graft. We use this method to graft Cedrus atlantica onto C. deodora stock, also some hibiscus cultivars onto more vigorous stocks.

Prior to grafting, the rootstock plants are moved into the glasshouse to promote growth, usually up to 10 days before grafting. At the time of grafting, lower branches and side shoots are trimmed off and an oblique cut is made in the stock at an angle of 20 to 30°, up to an inch (25 mm) long.

The scion wood is cut into a wedge at the basal end, these cuts being made as smooth as possible. The scion is inserted into stock while pulling the upper part of the stock backward, ensuring contact between the cambium layers. Once the top of the stock is released the scion should be held firm by the pressure from the stock. Then it is relatively easy to tie with raffia or rubber ties. The cut


Author: J.G. Short

PP: 336

The University maintains two small plant propagation units, one mainly concerned with growing plants for landscaping while the second unit is available for germinating seed and rooting cuttings of plants that are to be the subject of various research and demonstration programmes of the Botany Department. Some material comes to hand from time to time collected in the field by botanists who require a closer study of genera and species and who wish to have such plants propagated and grown on before they are classified.

For some 12 years, we have been propagating and growing on plants collected by Dr. J.W. Dawson who has published a number of important monographs on the family Myrtaceae. In the course of this collecting work Dr. Dawson has sent back material from travels in the Pacific region, particularly from New Caledonia. Some of the Metrosideros species thus collected, after growing on in the glasshouse, have been planted out into an open shrub border and have been found to grow and


Author: H.C.M Whitehead, K.L. Giles

PP: 340

A rapid method for the propagation of poplars by tissue culture has been developed. In comparison with conventional practices very large numbers of rooted plants can be rapidly formed from small explants and the potting mix can be manipulated to give establishment advantages to the tree when planting out. The technique also gives a method for the international exchange of poplar material under sterile conditions, to eliminate the danger of disease introduction, in a form that can be quickly bulked up at any time of the year.

Author: P. Markham

PP: 343

One of the most important aspects of propagating deciduous azaleas is the preparation of the mother stock. As time is the overriding factor, it is advisable to have stock plants containerized to ease handling.

During October, we move the stock plants into a glasshouse which has a day temperature of 18°C and a minimum of 15°C night temperature. Fluorescent lights are used to extend the day length to 11 hours. The stock can be re-potted just before being moved into the glasshouse but we have found that care should be taken not to damage the fibrous root system as this can cause collapse of the young shoots as they are forced into growth. Possibly the safest way to topdress the container is with a nitrogenous fertilizer, such as Uramite, 4 to 5 weeks before bringing them into the glasshouse. To further stimulate growth all flower buds should be removed without damaging the vegetative buds immediately below them.

The stock plants, held under the conditions described, show signs of


Author: J.S. Wallis

PP: 346


In late February and early March cutting material was gathered from near the base of the standard ("tree") fuchsia plants. This basal growth tended to be more vigorous and sturdy and better suited to our requirements than top growth.

Tip cuttings of approximately 10 cm (4") long were made. The bases of the cuttings were dipped in Seradix II, before insertion in sharp river sand, with a bottom heat of 10° to 16°C.

It was found that no misting was necessary; a good watering 3 to 4 times per day was all that was required.

About two or three weeks later, roots were beginning to push and the plants were duly lifted from their rooting medium and potted into 3" fibre pots.

The potting medium was "John Innes" and consisted of 7 parts loam, 3 parts rotted leaf mould, 2 parts river sand. As there was a plentiful supply of fallen leaves in the autumn, rotted leaf mould was used in place of peat, with outstanding success.

The fertilizers added per cubic yard were: 2 lb superphosphate, 2 lbs dried blood


Author: William Rogers

PP: 348

This paper is a description of a set of records I kept for a period of four years which helped me to go about my work more efficiently an make better use of my labor force.

I am the Production Manager of a container shrub unit attached to a mainly retail nursery. The production area covers about two acres and has turned out from 40,000 to 70,000 units a year of from 5-inch to 1-gallon sizes. I have a staff of 2 to 3 males and 2 females, mainly trainees. When I came to my present job ten years ago from growing house plants, the methods, soil mixes and so on were all new to me. The nursery was fairly new; the firm's outlines were set out but, in detail, were fairly sketchy. If one area of the nursery was under pressure we could be called on to help out.

It was felt after 12 months that productivity was too low, and I was encouraged to do some reading in management and work study. One of the main problems was to find out WHY we weren't turning out as much as expected. We were keeping


Author: W.L. Van Dyk

PP: 353

Three years ago we commenced relocating our main propagation department from the present site in New Plymouth to our 176 acre production nursery 10 miles north. This was to be completed in three stages. Stage 1, which consisted of 8,000 sq ft was completed 2½ years ago. Stage 2, of an additional 10,000 sq ft is now operative.

The old propagation department is largely made up of glass, rigid type plastic structures, and polythene houses of a variety of shapes and sizes built over a period of 70 years. The cost of re-building in glass was prohibited so we decided to seek a cheaper substitute for our million plus cutting production per annum. Plastic with it's low level of capital investment seemed to be the best alternative.

The Lee Valley Experimental Horticultural Station started work on film plastic structures in 1968 and has largely overcome the resistance to plastic tunnel developments. We based our design with modifications, on their prototypes as described in Station Leaflet No. 17


Author: G.N. Goldie

PP: 356

The Kowhai, pronounced by the Maori, kor-f-eye, means yellow and this is most evident throughout both islands from August to November when plants of this genus burst into flower often on sparsely-leaved branches, according to the species and district. Some overseas visitors have referred to the Kowhai as the New Zealand laburnum while many enthusiasts have proposed that it should be the national flower. The golden, drooping flowers, symbolic of spring, provide abundant nectar and pollen for such visitors as the tui, bellbird, kaka, silver-eyes, bees, butterflies and night-flying moths. No wonder the Kowhai never fails to gain the admiration of the horticulturist or of anyone who appreciates the beauty of nature.

The following descriptions and comparisons within the New Zealand genus should help to clarify some of the uncertainties that may have existed in understanding the Kowhai.

The genus Sophora (from sophera, an Arabic name for some leguminous trees), is not confined to New Zealand,


Author: Tok Furuta

PP: 63

Where is your company headed with respect to profits, costs, and prices? Can you plan for a given profit? Yes, you can!! Planning is a never-ending responsibility and opportunity: determining the company's goals and the organization and people required to attain them. Planning faces you squarely toward the future.

Planning cannot be done in a vacuum. Facts must be available for plans to be made, facts about your business and about the business world that affects your business. Among these facts must be what you expect to be spending for the goods you produce and sell.

Do we want to consider procedures to determine costs? Do we want to consider what 1-gallon plants, peat, containers, etc. cost me and you and you? Do we want to consider standardized costs for the industry? Do we want to consider what to do with the data we have? Many other questions can be raised — but enough!!

For this discussion I intend to cover, first, a general procedure for looking at costs; second, some procedures


Author: F.D. Hockings

PP: 362

In recent years improved selections and a few hybrids of Australian native plants have appeared in the nursery trade as well as an increasing number of species. However, these are still very few compared with the enormous number of native species with ornamental value.

Many apparently little known species are being grown only by specialist growers such as members of The Society For Growing Australian Plants. This same Society has been and is very active in all states in furthering an interest in use of indigenous plants in parks and gardens.

One of the more obvious results of this interest is the Canberra Botanic Gardens which is, I believe, the only botanic gardens in the world devoted exclusively to its continent's indigenous flora. I should mention also Maranoa Gardens and the extensive use of natives in airport and freeway plantings in Melbourne, the specialist gardens such as Stony Range, Kuring-gai Wildflower Gardens, and Bankstown Wildflower Reserve in Sydney and nearer at hand, the


Author: Paul de Lance

PP: 369

The Electric heating of seed and cutting beds and of hot-houses has resulted in a marked improvement in plant production and quality.

With tomato seeds the heating of seed beds has reduced the time between seeding and planting by five weeks. Capsicums, which are normally difficult to raise during the winter, sold four to five weeks before seedlings planted from unheated beds. Croton, hibiscus, camellia, macadamia, celery, and passion fruit have been produced with great success, being struck and grown during the winter and sold in early summer. The grower can now compete on a market where it was not possible to do so before.

The use of 32-volt system enables low cost, easily replaceable galvanized iron wire elements to be used. These can be installed by the grower and adapted to suit his particular conditions and application.


Author: R.A. de Fossard, R.A. Bourne

PP: 373

The red-flowering gum, Eucalyptus ficifolia, is a very attractive ornamental tree which is propagated by seed because, like many tree species, it is difficult to propagate by cuttings, budding and other classical methods of vegetative propagation. Although the flower colour on individual trees is the same, it is highly variable on different trees reared from seed and can be white, pink, orange, scarlet red or maroon. A method for the clonal propagation of E. ficifolia using nodal culture has been developed which involves first the culture of nodes, second the subculture of nodes excised from shoots on the primary cultures and finally the initiation of roots on subcultured nodes.

Author: Ross Worrall

PP: 379

Because the price of peat, especially the imported sphagnum type, has risen dramatically over the past few years there has been an increasing interest in the use of substitutes. One of the most widely available substitutes in New South Wales that could be used is sawdust. This has many of the desirable properties of peat. There are however several major drawbacks in the use of sawdust.

The first is that after an initial lag phase the sawdust absorbs a large amount of nitrogen from the potting mix. The rate of absorption depends on the temperature and the type of sawdust (Table 1).

Another problem is that many kinds of sawdust contain large amounts of substances (mainly phenols) which can inhibit the growth of plants (Table 1). Since most of the hardwood sawdust that is available locally is composed of two or more species it can be seen that the nitrogen uptake and the amount of toxic compounds in them will vary widely.

Although softwood sawdust is likely to be more uniform, much of


Author: R.H. Powell, M.W. Hagon, M.J. Mortimer, P.S. Semos

PP: 382

The climate and soils of much of the inland region of Australia make maintenance of grassland of European standards prohibitively expensive. Maintenance conscious planners have therefore welcomed the growing public acceptance of landscapes with the yellow, red and brown tints that are characteristic of many Australian grasslands. Native grasses are now being considered for use in a variety of landscape situations, but particularly on low-wear sites such as roadside verges and medians, nature trails and dryland reserves. It is expected that the adaptation to drought and low fertility soils of native grasses will greatly improve their establishment and stability on such areas in comparison with most exotic grasses (6,7).

Basic investigation into techniques of native grass establishment was required before these could be considered as a substitute for exotic grasses. Methods have been developed for propagation from seed of four native grasses: the warm-season grasses, Themeda australis


Author: A.N. Green

PP: 388

This hardy evergreen shrub is widely used in private and public gardens throughout many areas of Western Australia but mainly in coastal regions south of Carnarvon and inland to the wheatbelt where it is cultivated as a garden shrub in low rainfall districts and with minimum irrigation.

Known locally as Geraldton Wax, it flowers profusely from June to October. Flowers consistently of a disc of five petals are borne on the terminal growth, and have a waxy appearance. They have lasting qualities and make excellent cutting material for florists.

Leaves are short fleshy needles, soft to touch with a strong distinctive aroma when bruised and are rich in oil.

Although it grows readily from seed, about 12 selected cultivars are perpetuated from cutting-grown stock to obtain these better coloured forms. These range from white, pale pink, deep pink to purplish red.

Cuttings are taken between January to April but my best results have been from those taken in late March and early April.

Tip cuttings 2


Author: Alex Scott

PP: 389

Hibiscus is a line that we grow well and have built up an Australia-wide trade supplying something like 50,000 a year in containers from a 2" tube to a 4" liner. There is a particularly strong demand for the Hawaiian type of hibiscus. This type produces extremely large flowers in some very unusual shades and colours. Examples which I feel would be known in any areas where hibiscus is grown are ‘Surf Rider’ and ‘Golden Belle’.

When we first started to produce the Hawaiian cultivars from cuttings our stocks bushes were young and vigorous and our production results were very high indeed. However as the stock bushes matured, the strike became less and less. I was faced with the decision of having to bed out new stock bushes every few years, or to look into the possibility of grafting.

We had to develop a technique that we could use as our standard procedure and one which could produce a high percentage of success. We set down a series of trials to determine:

  1. The most suitable rootstocks.

Author: Lincoln M. Doggrell

PP: 391

Macadamia trees were regarded as impossible to graft up to the 1920's. Around this time a high school student in Hawaii successfully grafted two macadamias. However, it was probably not until the late 1940's that any large scale commercial grafting of macadamias took place in Hawaii.

In Queensland grafting of macadamias was still generally an unsolved mystery by 1960 with one or two notable exceptions. One man in particular, Mr. Norman Greber of Beerwah, had mastered the art successful grafting technique. Mr. Greber could not understand the failures of others to copy his method. This continued failure at propagation was the major stumbling block to the establishment of a macadamia industry around this time.

Mr. Greber's graft is a modified side wedge which allows almost any sized scion and stock to be united. Success rates were generally high with rootstock sizes ranging from small seedlings to limbs on topworked trees 6 to 10 inches in diameter. This method was adopted by one or two


Author: Stanley T. Henry

PP: 393

Australia has many beautiful and useful native plants but macadamia is the only one under cultivation to produce food for man.

Grafting of macadamis is not as easy, as fast, or as sure as most orchard species. This is demonstrated by the early difficulties experienced with grafting macadamia and the numerous propagation methods which have been developed.

In 1969 scionwood supplies of desired cultivars was in short supply. We offset our scionwood shortage by going onto patch budding instead of grafting. Results and propagation rate were similar to grafting. (Propagation rate was approx. 100 / man / day.) It was while doing this laborious patch budding that the idea of punch budding occurred to me.

On 15th January, 1970 two 0.303 bullet shells were used to prove that macadamia buds could be punched. Our first punch-budded trees resulted from this and tens of thousands of trees produced since then have proved the benefits of punch-budded trees for CSR Limited requirements.


Author: R.K. Ellyard

PP: 395

In studies undertaken with five Australian native species supplementary light was found to produce a small but statistically significant increase in the percentage of cuttings which rooted and in the number of roots per cuttings. In a study using 9 species a concentrated-dip auxin application of IBA + NAA was found to be far superior to a talc dust containing only IBA in increasing both the percentage of cuttings which rooted and the roots produced per cutting.

Author: D.E. Kester

PP: 71

The subject of juvenility in plants is receiving increasing attention from propagators, horticulturists and foresters both from academic interest and practical necessity. A worldwide study group for horticulturists, foresters, and pomologists interested in juvenility has been formed under the auspices of the International Society for Horticultural Science. In 1975, two international symposia were held, one in Beltsville, MD., U.S.A. and one in Berlin, Germany (17)a.

Most interest in juvenility focuses on 3 significant practical problems. First, how can one maintain or increase the rooting potential and regenerate hard-to-root cultivars by vegetative propagation? Second, how can one shorten the juvenile period to bring about early flowering to speed up breeding programs for fruit, nut and forest crops? Thirdly, how can one avoid (or utilize) the variability in growth performance and morphological appearance that sometimes characterizes juvenile growth

Relationships, such as the effect of


Author: Harold W. Caulfield

PP: 402

My first experiences at germinating palm seed showed that freshness of the seed was an important factor. Fresh seed of the ‘Kentia’, Howeia fosteriana, and Phoenix canariensis palm was available and germination never presented a problem. Seed of Phoenix roebelini, ‘Dwarf Date’, had to be imported so was up to many months old at arrival. Germination was poor and sporadic.

Subsequent tests with a variety of palm seed showed conventional techniques such as filing, chipping and acid baths for aiding germination of hard-coated seeds were ineffective.

In 1958 Dr. Walter Hodge, then President of the Palm Society, visited the Botanic Gardens and this led to exchange of seed and information from authorities such as Bruce Ledin, Stanley Kiem, Nat De Leon, Harold Moore Jr., and a host of others.

As a result of the exchange of ideas, a lot of experimentation, experience, and a regular supply of seed, the following facts clearly emerged;

  1. Seed must be freshly harvested to successfully germinate.
  2. Only mature

Author: A.T. Keane

PP: 405

Unless some form of national protection is established the achievements of plant breeders will be small and the immense possibilities of breeding from our native flora will not be realized. With other countries having their protection legislation this will be our loss unless we act quickly. Another factor is that with this protection overseas it is now almost impossible to introduce our strains to them without having reciprocal protection.

I, and other breeders, have made great efforts over recent years to get this established but nothing has been achieved. It has, however, been a great pleasure to know that all our State and Federal Nurseryman's Associations have formed a Plant Breeder's Rights Committee and are very active in this field. Currently, States have the power to enact appropriate legislation but I can not see the possibility of uniform legislation unless the states give this power to the Australian Federal Government.

An ordinary patent was taken out three years ago on a


Author: B. Minus

PP: 406

The magic of landscaping is definitely here to stay and we are faced with the challenge of producing exactly what customers want.

We have at least four major groups of ground cover plant users:

  1. Suburban home owners
  2. Suburban and city townhouse and flat owners or dwellers
  3. Urban landscape contractors
  4. Contractors of large scale landscape restoration, conservation and management projects.

The first two groups of customers deserve particular attention. They buy mostly exotic intensive-care ground cover plants. Plant propagators can foster business goodwill and can make major contribution to the aesthetics of the environment in which these people live by merchandising well selected, high quality plants for the particular locality.

Sometimes these customers will need advice on how to use ground cover plants to the best advantage, how the ground cover plants can display other taller plants to advantage and how, with combination of ground cover and larger shrubs and trees, their homes, townhouses or


Author: John H. Colwell

PP: 407

I have spent many years in different branches of horticulture. Never have I seen an area that needs more attention than practical training. The trade is crying out for help in training — training for young and old; for nurserymen; and even the teaching staff themselves. Many think that the institutes are not geared to cope so they will not send their young to train there. The whole structure of training must be overhauled. There are many dedicated people working hard at it now but nowhere near enough. Training is the responsibility of all in the trade — educators, nurserymen, parks departments, botanic gardens, apprenticeship boards, students, apprentices, and nursery staff. We must all work together to get the results.

Author: J. Gordon

PP: 411

The Queensland Agricultural College offers a range of full time course in horticulture, ranging from a two-year Associate Diploma courses designed to train technicians and supervisors in the various horticultural disciplines, to a degree course in Horticultural Technology.

Traditionally, horticultural teaching at the college has centered around fruit and vegetable production, but now the scope has expanded with the introduction of specialist subjects such as Nursery Production, Ornamental Horticulture, Landscape Gardening and Turf Management. These specialist subjects are designed to meet the needs of the various sections of the horticultural industries and they have originated partly as a result of pressure from industry groups, such as the Queensland Nurseryman's Association, and the International Plant Propagators' Society. Our main emphasis now is on the development of the necessary practical facilities to effectively teach these subjects, particularly the facilities for the


Author: Steve Clark

PP: 415

Camellia reticulata has been propagated in this nursery for many years by cleft grafting. However the numerous disadvantages — use of four-year-old understocks, no buds formed in the first season after grafting, single stem with few or no lateral branches for the first year — made a cutting-graft seem worthwhile trying.

A side veneer graft carried out in the summer has worked well. The procedure is as follows.

Camellia hiemalis ‘Kanjiro’ is used as the understock. a vigorously growing plant that has made stout shoots on the top is selected. Understock cuttings are prepared about 5 inches long with 2 or 3 leaves. A single sloping cut about ½ inch long is made into the stem about 1 ½ inches from the base. This is where the wood is thickest and the possibility of cutting right through is minimized.

The scion of the desired cultivar is prepared by cutting to approximately 3 inches in length with two leaves at the top and the base is shaped into a wedge about ½ inch long. The scion is