Volume 10

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COMPATIBILITY IN GRAFTING AND BUDDING FRUIT AND ORNAMENTAL PLANTS FOR ADAPTATION AND DWARFING PURPOSES

Author: D.B. White, J.P. Mahlstede

PP: 50

This is the first progress report on a project initiated at Iowa State University in 1956 entitled "Dwarfing of Fruit and Ornamental Plants." One of the primary objectives of this project is the development of techniques for dwarfing and adapting ornamental plants to different soil of climatic conditions. Many select plant materials, normally tall growing, would be well suited for use with modern contemporary building designs if height development could be restricted. Since this project was initiated, several stations have reported on similar work which is either underway or in the planning stage. The number of projects re-affirms the need for an increased inventory of low growing plant materials having acceptable ornamental characteristics, for areas differing in soil and climatic conditions.

One of the most common problems encountered in grafting is that of incompatibility. This inability of two components when grafted together to produce a healthy plant has been known for many

ESTABLISHMENT AND MAINTENANCE OF STOCK BLOCKS

Author: F.L.S. O'Rourke

PP: 95

It has been shown that stock blocks established for a ready supply of propagative material must be well fertilized, sprayed for pests, given weed control, and irrigation when necessary. Other factors to consider are site selection, economy of space, pruning, and virus-free certification.

The site for stock plants grown for softwood cutting material should be convenient to the greenhouse so that collections may be made frequently when the wood is in just the right condition. On the other hand, plants grown as a source of seed, scionwood, or hardwood cuttings, may be grown wherever space is available. Neither the best nor the worst land should be used for this purpose. Sloping land should be planted on contour in conformity to good soil conservation practices. Fertility and available water are always prime requisites for the production of propagative material.

Nurseries and arboretums often feel compelled to keep propagating material of a large number of different clones, even though

ESTABLISHMENT AND MAINTENANCE OF STOCK BLOCKS FOR PROPAGATION

Author: Louis Vanderbrook

PP: 96

In the establishment and maintenance of a stock block for cutting purposes, layering, stooling or whatever method of reproduction you plan to use, we first have to consider the advantages and disadvantages of such a venture.

Let us first consider the advantages of a stock block. The establishment of such a planting will enable us to:

  1. Have our source of supply close at hand.
  2. Give strong healthy cuttings as a result of controlled fertilization and cultivation.
  3. Enable us to secure our cutting material when we want it with a minimum of time.
  4. Be sure our materials are disease free by use of proper controls
  5. Help preserve juvenility.

Now the disadvantages of planting and maintaining a stock block are as follows:

  1. We will have to invest some capital to set aside an adequate amount of good land
THE ESTABLISHMENT AND MAINTENANCE OF A STOCK BLOCK OF HARDY HYBRID RHODODENDRONS

Author: Richard Vanderbilt

PP: 99

REASON FOR A RHODODENDRON STOCK BLOCK

A good stock block enables one's entire production to be taken from plants that are true to name. It is possible to produce more cuttings of better quality than when cutting plants which are destined to be sold. In working over material to be sold there is always the conflict of wanting to take the best propagating material and simultaneously doing whatever is best for the plant being cut. A stock block allows more flexibility. We may treat salable aged plants, or those being grown to be sold, to produce the maximum amount of body and to encourage flower bud development, while treating mother plants to produce the maximum amount of vegetative growth and to hinder or halt reproductive activity.

In addition a stock block provides a more reliable source of cuttings year after year.

USE OF MULCHES IN THE NURSERY

Author: Case Hoogendoorn

PP: 111

Since we do a lot of propagating, we had the same trouble everyone else has and that is to keep ahead of the weeds in the beds. This is usually all handwork, which is costly and consumes a lot of time.

Before we began to use a mulch, the soil in these beds, consisting of a heavy loam, was very hard in the spring, after the heavy winter rains and quick drying spring winds. Trying to break up that soil in the spring with a scratcher was slow work and was hard on the wrist, which has bothered me for years. So I started to look around for a better method to control these weeds and the hard soil condition After looking around I started to eliminate various mulch materials for one reason or another.

I had seen the sawdust used, which I thought had disastrous results. It broke down too fast, robbing the soil of nitrate nitrogen. As a result the plants turned yellow and needed constant feeding with nitrate. For that same reason I did not dare to use wood chips, chopped straw or hay. Then we

RESEARCH IN ROOT INITIATION — A Progress Report

Author: Charles E. Hess

PP: 118

As many of you will remember from last year's talk (2), we are attempting to establish chemical differences between easy-to-root and difficult-to-root cuttings. One of the plants we are working with is Hibiscus Rosa-sinensis. The red flowering form of this plant is easy to root and the white form is difficult to root. In addition we have a third variety which is intermediate in its ability to root. By extracting the tissue of the three forms of Hibiscus we find four separate root promoting substances in the red Hibiscus, three root promoting substances in the Hibiscus which is intermediate in its rooting ability, and two in the difficult-to-root Hibiscus. In other words, a correlation exists between the number and the amount of root promoting substances we can extract and the rooting ability of the cutting — the easier a cutting is to root, the more root promoting substances can be extracted. The root promoting substances are not related to indoleacetic acid (IAA), the natural plant
SUCCESSFUL WINTER GRAFTING OF JUNIPER VARIETIES ON UNROOTED CUTTINGS

Author: Constant DeGroot

PP: 124

Grafting the genus, Juniperus on unrooted cuttings is not new. Some will remember when James Wells talked about it at one of our earlier meetings. It has been tried before on Juniperus virginiana plumosa and hetzi. I have tried it also, but the results were not very encouraging, perhaps because the know-how was missing.

The most common practice is to graft on potted seedlings of J. virginiana, since they are easy to get in large quantities. The result, however, can be very alarming. You may have the misfortune of having the entire crop hit by blight, which results in very heavy losses in the potted understock. Last winter we did not have 50 per cent of our stock fit to graft on. For all the time and land it takes to produce a two year seedling, I have never seen a good ball dug on a juniper that was grafted on J. virginiana. Taking these four points into consideration for a ten year period I doubt if the overall stand in the field would be over 50 per cent.

Those varieties grafted on

PROPAGATION OF GINKGO BILOBA BY CUTTINGS

Author: John Vermeulen

PP: 127

When Martin Van Hof asked me last Fall if I could fill in with a paper about the propagation of ginkgos I told him that I would try and explain our experience with this plant. We started with the propagation of male ginkgos about ten years ago, but due to several more important things we were trying out we did not take a serious interest in it until the summer of 1957.

As you all know the ginkgos are readily propagated from seed. In this seedling population you get both female and male trees. These female ginkgos produce a lot of seeds which, when they do drop off in the early fall and are stepped upon, leave a very unpleasant odor. To eliminate this serious problem many nurseries have been grafting or budding the male ginkgo. However, as with many other plants the question of ease and expense of production arose. If there was an easy method of propagation the male ginkgo could be sold at a more reasonable price and produced in larger quantities.

We, as propagators of small plants,

PROPAGATION IN FRAMES USING ELECTRIC CABLES FOR BOTTOM HEAT

Author: Richard Van Heiningen

PP: 130

I would like to give you a little history of our propagation method so that you can see how we sort of walked into the electric cable method of propagation.

My father, who ran the Evergreen Nursery Company in Wilton, used frames exclusively for the propagation of evergreen cuttings. He was supplied in the wintertime with horse manure, until Bordens and Sheffield Farms turned from horses to trucks. When there was no manure available, they continued to propagate in frames but with inadequate bottom heat. It was their procedure to make cuttings in the summertime, starting about July.

Now this encompassed all sorts of evergreen cuttings that are familiar to you, such as arborvitae, chamaecyparis, taxus, and the junipers. They had rather good success. I think it was to some extent similar to mist propagation, because when the cuttings were once in the frame they were kept nearly airtight by bags placed underneath the sash. The frames were not opened unless it was necessary to syringe them, which was done on a sunny

WILL SEED FROM NORTHERN PLANTS PRODUCE PLANTS HARDIER THAN THOSE FROM SOUTHERN REGIONS

Author: Thor K. Bergh

PP: 141

Mr. President, Mr. Chairman, members of the Society and guests. It is a real challenge to present a talk on a subject that, I am quite certain, is very familiar to some of you, probably most of you. Not only is this a challenge but also a distinct honor for me and for the Soil Conservation Service, the agency that I represent, to have the privilege of talking to you today.

The title that was assigned to me is "Will Seed From Northern Plants Produce Plants Hardier Than Those From Southern Regions?". This may be a controversial subject. I am sure that some of you feel that you have an answer to that question.

Many of my comments will stem from my own experience, some from work of colleagues, and some from work of others about which I have read or heard.

With your permission, I may deviate a little now and then from the subject of hardiness and swing occasionally into the subject of adaptability. They seem to go together, and it is often difficult to discuss one without also mentioning the other.

OVERWINTERING OF SOFTWOOD CUTTINGS UNDER CONTROLLED TEMPERATURES

Author: Vincent K. Bailey

PP: 154

The present day propagator has been given the knowledge, through recent research, of how to root softwood deciduous cuttings at a low cost This know-how has been spread by our universities and such organizations as the Plant Propagator's Society We have all cut our costs tremendously by adopting these new methods.

I feel that the propagators work does not stop at putting roots on a cutting. If he can not produce a finished plant economically, he is soon in financial trouble in this very competitive world. The transfer of this rooted cutting into the field has been a challenge to all of us. Many are getting good stands by placing them in bands or pots for a time and then transferring them to a field. There are a number of variations of this procedure but it is very costly in time and labor.

In order to reduce this high labor cost, we started six or eight years ago to transfer these rooted cuttings directly into the field. We were well satisfied with the results in all ways. The stands

EFFECTS OF OVERFERTILIZATION ON CONTAINER-GROWN PLANTS

Author: James D. Kelley

PP: 58

The widespread practice of growing nursery stock in containers has brought about a need for more information in regard to the fertility requirements of woody ornamental plants. Fertilization has always been important in growing quality nursery stock, however, fertilization assumes even greater importance when a plant is grown in a restricted volume of soil such as exists in a container. There are many unanswered questions concerning this type of culture. One question that has been of great importance is the fertilization practices necessary for producing quality nursery stock in containers Little is known about the fertility requirements of woody ornamental plants. However, the limited volume of soil that is available for supplying the necessary nutrients of a plant in a container necessitates that for optimum growth, fertilizer be applied to supply the required plant nutrients.
NOTEWORTHY VIBURNUMS

Author: Ronald R. Egolf

PP: 158

The genus Viburnum, of approximately 175 species, does not require an introduction to this Society; as it is one of the staples of the nursery trade. You are familiar with one or another of the snowballs, guelder roses, or blackhaws. There are few ornamental groups of plants which display such diversity of form and are adaptable to as wide a range of conditions as Viburnum.

The group is widely represented in the north temperature zones of both the eastern and western hemisphere. The native species of this country may not equal their asiatic cousins in spectacular flowering and fruiting characteristics, but they include several of the most adaptable forms. The species widely cultivated are natives of Asia, Europe or North America. In Addition to the few forms known to most nurserymen there are innumerable choice species that are practically unknown. As seen on the map of the distribution of Viburnum the major centers of concentration are in Asia, Eastern

PROPAGATION OF SCIADOPITYS VERTICILLATA

Author: Sidney Waxman

PP: 178

The Japanese umbrella pine is certainly a highly desirable tree. It is a pyramidal, closely compact tree with glossy foliage. It is almost entirely free from insect and disease injury, and on the whole is a plant we should use more.

It is an interesting tree from several aspects, ie, it belongs to a genus that is composed of only one species, and no other evergreen resembles it, in fact, no fossil records of it have ever been found. It is thought by some people to be a remnant of an age long past.

There is a natural stand of these trees in the mountains of Japan, (Mount Kojasnin), where they have attained a height of from 79 to 90 feet. Specimens are only rarely seen in this country. However, more people are now becoming quite interested in this plant and there are several nurseries in the New England area that are growing them. The umbrella pine is fairly hardy, growing as far north as Portland, Maine. Most umbrella pine are found in the East. Also, I understand that there are some

PRE-EMERGENCE WEED CONTROL IN NURSERY CROPS

Author: W.E. Chappell

PP: 186

INTRODUCTION

The term "pre-emergence" when used in reference to weed control usually means an application of chemicals after planting, but before the emergence of the crop or weeds. In the case of transplants or liners, however, it would be pre-emergence to the weeds only. The selection of the chemicals to be used for pre-emergence weed control will depend on whether it is being used on direct seeded crops or whether it is to be applied as a directed spray on lining out stock and also whether a liquid or granular application is being made. Certain sprays cannot be used on liners even when it is directed at the base of the plants without taking some chance of producing some injury The same chemical might be applied as a granular formulation without any injury.

CHEMICAL WEED CONTROL IN THE NURSERY

Author: John Newhouse

PP: 189

Chemical weed control, properly used, is one of the best money-savers that has been introduced to the nursery business in many years. The days of planting material by hand and hand weeding or hoeing are fast disappearing.

Any material that will kill certain types of plant growth while allowing others to grow is dangerous if indiscriminately used. When using any of the materials on the market today, it will certainly pay to follow the manufacturer's recommendations and try the material to be used on a small scale to ascertain how it will act under local conditions.

In our case, the young stock planted in beds was the most expensive area of the nursery to keep clean. The material planted in field rows is planted so that mechanical cultivation is possible, leaving very little hand work to be done. Labor in our section of the country is probably quite a bit higher than it is in most, making it nearly economically impossible to grow our own liners.

Our area of bedded stock consists of about 2&frac12 acres. In an area

USE OF THE PEAT POT AS A FORCING CONTAINER FOR HYBRID TEA ROSES*

Author: J.P. Mahlstede

PP: 197

INTRODUCTION

With increased production and sales of ornamental plants grown in containers, both the producer and merchandiser would like to find a substitute for the Number 10, black asphalted can that has been used to produce much of the stock grown in the "one gallon" size of container. Emphasis on packaging has called the attention of nurserymen to the need for a dual purpose growing and selling container for the smaller sizes of landscape ornamentals. Functional, colorful, plantable, cheap pots would have an increasing, expanding market in the years ahead.

It was therefore the purpose of this study to determine if the 6" &times 9" experimental peat pot* fitted with a polyethylene jacket might serve as a forcing container for hybrid tea roses, which are usually potted early in the spring, forced, and sold during the summer months.

USE OF THE PEAT POT AS A GROWING CONTAINER FOR ORNAMENTAL PLANTS*

Author: J.P. Mahlstede

PP: 199

INTRODUCTION

It is a common nursery practice to grow ornamental plants in various sized containers for periods of time varying with the type of plant and size desired for marketing. It is possible with plant types which make up quickly, to start in the early spring with a well rooted cutting and produce a finished, landscape sized plant in one gallon container in one growing season. Slower growing plants, which includes many of the evergreens take much longer to reach marketable size, and for this reason are often shifted up from smaller containers before they are sold.

The purpose of this study was twofold, first to determine the feasibility of using a peat pot having a polyethylene jacket as a growing container for a rapidly growing and a relatively slow growing plant, and second to establish the response of these two types of plant materials to different mediums.

THE EFFECT OF NODULES ON THE ROOTING OF CUTTINGS OF JUNIPERUS AND THUJA

Author: Gary L. Wilms, F.L.S. O'Rourke

PP: 203

The side branches of certain species of Juniperus and Thuja, particularly those on the lower portions of the tree, often have swellings or tissue protuberances along the stem There are termed "nodules" in this report. The cause for the development of these nodules is not known and has been variously attributed to environmental conditions, to genetic factors, and to the physiological condition of the tissue known as juvenility.

Past experience and observations made at the Gwenn-Gary Nursery, Columbiana, Ohio, in large-scale production of cuttings has shown that those cuttings with nodules on the stems rooted more quickly and produced more roots than those without nodules The differences were particularly noticeable with cuttings of Spiny Greek juniper (Juniperus excelsa ‘Spiny’) as those with nodules rooted 70 to 80 percent, while tip cuttings without nodules rooted as low as 10 to 15 per cent A study was therefore made at Michigan State University during the winter of 1960 to compare the

GERMINATION OF DOUBLE—DORMANT SEEDS

Author: Alfred Fordham

PP: 206

The discussion will deal with the two stages of pretreatment necessary for seeds with epicotyl or shoot-bud dormancy, together with the method of shortening the usual time needed for germination. Due to the length of time normally required to germinate them they are in the category of so-called two-year seeds.
THE PLANT PROPAGATOR — THE BASIS OF OUR INDUSTRY

Author: James S. Wells

PP: 229

MR. CHAIRMAN. Fellow growers

It is customary for the speaker to begin by saying how pleased he is to be here, but I do so on rather a different level because it is not often that a speaker has the opportunity to give essentially the same speech under the same title twice in ten years

It was in 1951 that the Plant Propagators Society came into being, and quite by chance it fell to my lot at that time to put forward some ideas as to how our society should be organized. Last week, as I read through the proceedings of this first meeting, I realized that I could hardly improve on what I had said ten years ago. It might be simpler if I suggested you read the first three or four pages of proceedings Number I and sat down. However I feel you expect a little more of me than that.

I am deeply conscious of the importance of this meeting to you and of my responsibility to it. Fortunately my position is rather an impregnable one, because events have proven that the ideas of ten years ago have

MECHANIZATION OF GRAFTING METHODS

Author: Lloyd A. Lider

PP: 238

The panel discussion of machine grafting techniques which has been placed on the program this evening exemplifies the basic reasons for desiring to establish this society and for its meeting together this evening. The vegetative propagation and grafting of perennial plants has been an important phase of commercial nursery operations for many years. Several specific horticultural industries in California are based upon the use of scion varieties grafted on special rootstocks designed for certain environmental conditions or because they are resistent to soil borne pests or diseases.

Techniques of propagation which insure the successful production of a dependable number of strong grafted plants for nursery sale are essential to the program of providing the planting stock for the expanding horticultural industries of this state.

Various types of mechanized grafting techniques have been used for several decades in the European grape industry. Many hundreds of thousands of bench-grafted

DISEASES IN PROPAGATING BEDS

Author: Spencer H. Davis

PP: 63

I realize that each nursery has its own particular problems. If you talk ten minutes about somebody's problems it is not of too much interest to the person who has a different type of problem confronting him. We are going to talk therefore, a little bit about the general diseases found in propagating beds. We are also going to think about what happens to many of these cuttings after they become plants. You people who grow these plants know enough about many of the problems. It is after these plants are sold and get into the hands of the customer that either the county agricultural agent or I start to get questions; this is when we have a problem. I am going to try therefore to hit both of these sides.

First of all, let's take the non-infectious diseases. They are usually easy to correct. You can get 100 per cent results with them, but you don't have any interest in these because you know the answers to them.

Cankering is common on taxus after it has been lined-out in the field. We find it

MACHINE GRAFTING AND PREPLANTING TECHNIQUES FOR GRAPE BENCHGRAFTS

Author: Curtis J. Alley

PP: 239

Before the introduction of phylloxera into France around 1868, and into California about the same time, there was little need for grafted or budded grapevines. Most grapevines were developed on their own roots, generally by rooted cuttings grown in the nursery the previous year. Phylloxera, however made it imperative to grow desired fruiting varieties on phylloxera-resistant stocks. The same was true of sandy areas where nematodes were a troublesome pest. When resistant rootstocks were first used, hand labor was the chief method of making the benchgrafted vines. Where labor costs are low, such is the common practice even today.

Present economic conditions in the U.S. prohibit such an operation. It wasn't long after benchgrafting became a reality that enterprising nurserymen and growers began to develop

MACHINE GRAFTING FOR GRAPEVINES

Author: Thomas D. Terry

PP: 247

This report relates the use of machines in grafting grapevines in a small California vineyard in Santa Clara County. It is a general non-scientific view of why this particular vineyard adopted machine grafting and how these machines were used and modified.

Before the use of machines, vines were budded in the field. A good budder, working with two assistants, would bud from 300 to 400 vines in an 8-hour day. There were other disadvantages besides this relatively slow rate. To find mature budwood before the rootstocks run out of water and cease growing is difficult in non-irrigated vineyards. This relatively short period, when field budding is possible, occurs in late August and early September, at the beginning of the vintage, the busiest season of the year. If the bud-graft does not take, that portion of the vineyard is idle for another year

In the winter of 1951–1952, the Novitiate purchased a grafting machine from Mr. Leon Brendel of St. Helena, California. This machine makes

MACHINE GRAFTING OF FRUIT TREES

Author: Gordon Kershaw

PP: 249

Dr. Lider and Plant Propagators: It was an honor to be asked to give my experiences in grafting fruit trees Dr Alley has asked me to relate some of my experiences in developing several types of grafting machines.

About 1951, we planned to graft some of our pear trees to the variety Red Bartlett. Since the wood was very scarce, we decided to make a bark graft using one bud, set in the stock. This would provide a better take.

We used a 5 kilowatt electric generator and an electric chain saw to remove the tree tops. A band saw was used to cut the scions, always leaving one or two buds on the top of the scion and making sure that one of the buds was facing the outside of the graft This method was successful in producing take as high as 98%. When this method was used on apple trees, the results were nowhere as satisfactory. The cambium seemed to be injured by the saw.

About 1953, we started growing Malling rootstock for dwarfing apple trees. We grafted apple root below Malling 7 and 9,

SEED PROPAGATION AS A NURSERY TECHNIQUE

Author: Vernon T. Stoutemeyer

PP: 251

Seeds often offer the simplest and most practical method of propagation, both for commercial production and for the person interested in the introduction and trial of unusual plants. Seeds are easy to bring from foreign countries, and they are much less apt to be damaged in fumigation than cuttings or scions. Seed minimizes, but does not entirely prevent, the chance of introducing some new foreign insect or disease. Few seeds carry any viruses

Many of the fine horticultural collections of the world have been built on the importation or exchange of seeds A good seed list of a reliable dealer is a kind of magic carpet which brings the plants of the world to us regardless of where we live.

Most of the seeds which we use in our nurseries present no particular germination problems for a reasonably skillful propagator or even the rankest amateur. If, on the other hand, we consider the whole field of plants we may fairly state that seed germination is indeed a complex problem.

The existing

SEED DORMANCY AND ITS RELATIONSHIP TO NURSERY PRACTICES

Author: Dale E. Kester

PP: 256

A seed may fail to germinate for three basic reasons First, it may be non-viable and thus incapable of development. Secondly, it may be subjected to environmental conditions which are unsuitable for germination. Thirdly, the seed may be affected by specific internal conditions — either in the seed coverings or in the embryo itself — which prevent germination from taking place until such time as these conditions are removed. The latter cause of non-germination will be the subject of this paper.
SEED STRATIFICATION TECHNIQUES, WITH EMPHASIS ON ROSES

Author: Dennison Morey

PP: 267

Several of my more sophisticated friends in the trade have asked me what I felt this new society was going to accomplish. I think this is a fair question I doubt that there is anyone who does not have trouble finding the time to get things done Few of us have time for frivolous affairs. I cannot blame anyone for wanting to be sure we are going to amount to something before investing much time in this embryonic society. Unfortunately, I must confess to them that I don't know what we are going to accomplish. I do know what I think we can do and should accomplish. Frankly, I believe this group can contribute a great deal to the stability and profitability of the nursery business.

There are two primary reasons for my view. The first is that the more dependable and economical propagation becomes, the more predictable and profitable production becomes. The second reason is my belief that only through cooperative development of knowledge and techniques can we hope to advance our methods last

SEED and SEED HANDLING TECHNIQUES IN PRODUCTION OF WALNUT SEEDLINGS

Author: William Stuke

PP: 274

For the past 30 years, I have been specializing in the growing of walnut trees. It is, indeed, an honor to speak to this distinguished group. During this time, many changes have taken place in the techniques of growing trees; also some in the demands of different stocks used for walnuts.

With advancement of agricultural sciences and the extensive research work by our men in the University in the different departments, many things have been learned which we did not know 20 or 30 years ago. For instance, we know that certain organisms attack the roots of walnuts. The ones with which we are primarily concerned are nematodes, more specifically, the lesion nematodes, Pratylenchus vulnus and Pratylenchus penetrans which are the most damaging to walnuts. There are, of course, other disorders with which we are concerned, such as crown gall, rootknot, nematodes, crown rot, etc.

We learned also of the desirability of other rootstocks which possess resistance to some of these diseases as well as

FIELD PRODUCTION OF SEEDLINGS IN A CENTRAL STATES NURSERY

Author: Hugh Steavenson

PP: 277

Each nursery, or certainly each region, evolves its own methods and techniques of propagation, according to local conditions of soils, climate, marketing opportunities, available skills and historic precedent. As a student many years ago, I came under the forest nursery influence. Shortly thereafter, in the mid-thirties, I had the opportunity of setting up one of the early soil conservation nurseries in Iowa, and this was followed by a 10-year stretch of developing and managing a similar nursery in Missouri. While Uncle Sam steered clear of the ornamental field, the wildlifers called for just about any kind of hardy shrub and vine, as well as many evergreens, while the foresters demanded an assortment of trees for erosion control and other plantings.

Thus when I established my own commercial nursery several years ago, it was only logical to pick up seedling production practices where I had left off working for the government.

In other discussions we have referred

PRODUCTION OF ROOTSTOCKS FOR ORNAMENTAL TREES IN THE CONTAINER NURSERY

Author: Gerd Schneider

PP: 282

For the discussion of rootstock production, of ornamental trees in the container nursery, I have selected five trees widely planted in Central California Although clonal reproduction is practiced with all of these trees, most of them are planted as seedlings Seeding techniques for container production differ only in few respects, when the young plant is to be used as a rootstock and when it is to be grown as a seedling specimen for planting The purpose of this paper is to focus on the seedling, which is to be used as a rootstock and to point out the practical steps and considerations necessary to produce that plant. I shall emphasize the selection of the seed parents, with a view toward obtaining material which is vigorous and of uniform size in the seed bed. I also want to emphasize some aspects of propagation unique to each tree.

The following trees will be discussed: Liquidambar styraciflua, Pistacia chinensis, Ginkgo biloba, Magnolia grandiflora and Quercus ilex

Liquidambar

EXPERIENCES WITH PROPAGATION OF THE GENUS PISTACIA

Author: Lloyd E. Joley

PP: 287

INTRODUCTION

Your program committee asked me to discuss our experiences concerning the propagation of Pistacia at the U.S. Department of Agriculture Plant Introduction Station, Chico, California, particularly as these experiences relate to P. chinensis.

Interest in the genus Pistacia is rapidly increasing throughout much of this country. Thus far this attention has centered on Pistacia chinensis Bunge, a fall coloring shade tree, and on P vera L., which produces the edible pistachio nut of commerce. Additional species such as P atlantica Desf, P. intergerrima Stewart, P. Lentiscus, L., P. terebinthus L, and some hybrids of these are also promising as shade trees or for rootstocks

Most of our research with Pistacia has been concerned with P. vera as a potential new crop for this country. To a lesser extent this research has also included work with Pistacia species and hybrids as rootstocks for P vera, and with P. chinensis as an ornamental shade tree Although there are problems in

THE PROS AND CONS OF BANDED VERSUS BARE ROOT MATERIAL

Author: George P. Blyth

PP: 72

We have been growing summer softwood cuttings, in containers for the past thirty years. We had difficulty in transplanting these to the field. We have used everything from clay pots, wooden bands, tar paper bands and plastic pots to peat pots. We find the Jiffy peat pots to be very satisfactory and are doing the best job to date. The advantages of banded liners applies to varieties that are difficult to transplant, or summer cuttings that are to be carried over the winter for spring planting or for shipping.

Our present method is to pot all our summer cuttings in Jiffy pots. We hold them during the winter in frames. The potting medium used is one-half sand and one-half peat. We fertilize once a week, using 20–20–20, Rapid Gro, until the end of August. The pots are covered in late November with line gravel to prevent heaving. The frames are covered with tar paper. This is removed in April and the potted cuttings are watered once a week.

We can begin planting in May. We use two Smallford planters drawn by a Farmall tractor. Four men plant approximately 20,000 per day at 12 inch settings. We have a very small loss.

BUDDING AND GROWING PISTACIA CHINENSIS FOR STREET TREES

Author: Dwight Long

PP: 294

The Pistacia chinensis has great possibilities as a street tree in all but the coldest climates, even in narrow planting spaces. The Pistacia becomes more value when budded from selected males on rootstock that has been selected for type and vigor. The best techniques for budding, growing and training have not, as yet, been fully established The City of Modesto Parks and Recreation Department, in the last five years, has tried a number of ideas with encouraging results.

We use the shield bud and have had the best success with using buds that have not pushed or enlarged, and the wood mature enough to be firm. This selection has given about a 96% take, whether budded in spring or fall, or at what height the bud is placed on the seedling stem

In growing the Pistacia, we have tried several methods and are still using or testing three. They are described as follows:

  1. Plants are field grown and bare root transplanted.
  2. Plants are field grown and bare root transplanted to five gallon cans
PROPAGATION OF TROPICAL PLANTS FOR THE FOLIAGE PLANT TRADE

Author: Robert Weidner

PP: 297

There is scarcely a species in this field that is difficult to propagate. There is scarcely a field where disease is so great a factor For this reason, we can never separate disease control from propagation.

We have reduced cutting loss to a point so close to zero that it no longer interests us to figure loss Cuttings grown under glass are expensive! We cannot afford to lose them.

In addition, under the sanitary conditions of the U. C. System, we have cut production time almost in half by being able to propagate a large percentage of our material in the pots in which they are sold. For example, Crotons take twenty-eight days to root to satisfy us. If rooted in bed, bare-rooted, then potted, we must allow nearly the same time for establishing. By rooting in the pot, we use merely the twenty-eight days From our point of view, this is a gift of 60% to 70% more greenhouses.

We have the usual aids — low and high pressure mist, heating cables, fan and pad cooling, etc. We have learned from

MIST SYSTEMS AND HARDENING-OFF PROCEDURES AT MONROVIA NURSERY COMPANY

Author: Martin Usrey

PP: 301

Description of the Intermittent Mist System

The intermittent mist system is composed of a series of mist nozzles controlled by a system of solenoid switches, clocks, and intermittent timers. The nozzles used are the Spraying Systems ¼TTN4W nozzle or the Flora-life wire baffle nozzle. The interval of misting varies between 12 and 18 seconds "on," every 6 minutes during hot weather and every 12 minutes during cooler weather. The TORK timer is used, because of its versatility in setting intervals. The timer makes a complete cycle each 6 minutes, however, by connecting all the interval timers to one master timer any multiple of 6 minutes is possible. In this way, the timers can be set to give the minimum amount of water for the corresponding weather conditions. Electric clocks are set to turn the system on in the morning and shut it off in the evening. The moisture present is usually sufficient to carry over the cuttings through the night.

MIST PROPAGATION WITH EMPHASIS ON HARDENING-OFF

Author: William J. Curtis

PP: 302

Mr. Chairman and Fellow Propagators:

I have been asked to talk to you gentlemen on "Mist Propagation, with Emphasis on Hardening-Off" We in the Northwest who propagate with mist, work under climatic conditions of greater variation than you here in California. However, we must meet certain conditions and factors that are common to both of us. First, a good, clean rooting medium must be used that will afford excellent drainage, second, a supply of good, clean water, third, bottom heat; and fourth, an assist from a rooting hormone.

We have, in the Portland area, good, clean, sharp sand. Several propagators are using PERLITE, a manufactured coarse material that affords excellent drainage yet has the ability to hold a great deal of water in its expanded structure. Clean, pure water is no problem; in fact, we sometimes have too much.

The bottom heat we use depends on the crop we are growing. We had several weeks of high, 90-degree weather this past summer. A 3-foot bench, filled with Clematis armandi cuttings, without mist, maintained a bottom temperature of 65 degrees, which seemed to be the right temperature for the best results. When the weather cooled off,

MIST PROPAGATION — HARDENING-OFF TECHNIQUES

Author: James S. Wells

PP: 305

Mist propagation has become such an integral part of almost any propagating nursery that it is interesting to recall that the first recorded instance of its use in plant propagation was in 1936, at Trinidad, British West Indies. By 1940, it was being tested in this country, and an excellent article in the American Nurseryman, May 1, 1941, by a nurseryman, Edward Gardner in Wisconsin, gave a long list of plants successfully propagated under mist. Then the war intervened, and most people lost sight of the method, although it was still in use at many of the state experiment stations. It was not until 1946–7 that practical work began once more. Mist, then, is a horticultural development of the first magnitude that has come into general use within the last 10 years.

As an essential preliminary to our discussion, we should first consider briefly some of the wider aspects of the misting techniques. I like to think of misting as being a better method of controlling water loss from cuttings,

ADVANTAGES OF BANDED OR POTTED LINERS VERSUS BARE ROOT MATERIAL

Author: Richard Vanderbilt

PP: 73

The usual and generally true arguments for potting are that there is less loss, more rapid establishment, more flexibility in planting times, and a better plant in a given time. But a visit to a good grower who wouldn't pot anything on a bet, shows that good plants may be grown without potting. I have in mind our neighbor Hap Hoogendorn, Case's brother, whose taxus can match or better anything we can do in pots following the U. C. mix and fertilizing every third irrigation. In addition to this, as far as I can tell, he has no loss, has very rapid establishment, and plants most anytime he feels inclined.

The chief benefit of potting for us is that we have been able to eliminate the planting of any coniferous material into beds, thus saving the tremendous amount of hand labor involved in keeping the beds clean. We are able to plant directly in the field, and to sell the liner directly from the row as a B & B plant.

ADVANTAGES OF BANDED OR POTTED LINERS VERSUS BARE ROOT MATERIAL

Author: Gerald Verkade

PP: 74

The three advantages to potting liners are (1) to maintain a higher survival with certain plants, (2) to produce a salable plant sooner, and (3) to extend the planting season. The main disadvantage is the added production cost which amounts to four to seven cents for each unit.

We use two types of pots in our operation. For our grafting understock we use a 2¼" plastic rose pot, which has to be removed before planting. For our cuttings we use a 2¼" or 3" square peat pot.

Cotoneaster horizontals, and C. praecox are potted because of low survival. I have found that leaving summer cuttings in the rooting medium until spring and transplanting them bare root has often showed a 25 per cent to 50 per cent loss. By potting them after they have rooted and placing them in a frost free frame, usually 95 per cent survive the winter and planting operation in the spring. Magnolias, viburnums, Pink dogwoods, and Japanese maples are also potted. These items after potting are placed in a controlled warm frame

THE MORE UNUSUAL ASPECTS OF PLANT PROPAGATION METHODS AND EXPERIENCES IN MIST PROPAGATION IN BERMUDA

Author: Donald J. Moore

PP: 80

Before proceeding into the main subject matter of this paper, it is, I feel, essential to acquaint you all with a few statistics relevant to Bermuda's geographical location, climatical data and topography. Whilst these factors may not effect propagation to any great extent in a broad sense, they most certainly do dictate problems to us locally. They do this in no uncertain matter.

Our climate may be described as sub-tropical. Geographically, however, we are located in the Temperate zone. Exact location, relevant to the nearest point of land, is 568 miles from Cape Hatteras. The nearest west indian island is Abaca, some 700 miles to the south west. Contrary, to general belief, we are not part of the West Indies, but are indeed, very much an isolated land mass.

We owe our congenial climate entirely to our close proximity to the Gulf Stream. Frost in unknown. The lowest recorded temperature is

EVERGREEN GRAFTS UNDER PLASTIC

Author: C.W.M. Hess Jr

PP: 87

For many years there has been little if any change in grafting procedures. The well known pony sash or half sash have constituted the standard enclosure for the Wardian Case. These sash are quite heavy, have an abundance of sharp splinters, and to air the grafted plants they must either be hung or removed to the greenhouse path. This procedure requires about a minute per sash for removal and replacement. This short period of time in itself doesn't mean much until you multiply it by the one hundred and thirty sash in a four bench propagating house, one hundred feet long. Approximately fifteen hours a week are required for the average seven weeks the grafts are in the Wardian Case. You will find that your pocket is lighter by more than one hundred and fifty dollars on this basis.

Realizing this overhead expense, some growers have experimented with mist lines to eliminate the need for using sash. During the summer this has proved very successful in grafting Japanese maples, dogwoods and

OUTSIDE GREEN GRAFTING OF RHODODENDRONS UNDER POLYETHYLENE

Author: David G. Leach

PP: 90

I am going to talk this afternoon very briefly about still another method of propagating rhododendrons.

Green grafting of rhododendron is a kind of a special situation, because I think almost anyone agrees today that a rhododendron is better off on its own roots. There are a few situations, however, where it is just about necessary to graft. There are a few rhododendrons that are not vigorous enough on their own roots and there are a few, that will not root from cuttings. Mrs. C. S. Sargent, for example, which is just about universally recognized to be about the finest often is described by the nurserymen as being impossible to root.

Rhododendrons have traditionally been grafted in the winter in the greenhouse. A few years ago I read about topworking old plants by grafting. I then adapted this technique to the propagation of new plants by green grafting, since it seemed to me to be far superior to dormant winter grafting technique.

The understock can be almost any kind of a two or