Volume 18

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Author: Richard Martyr

PP: 50

The newest chapter of the International Plant Propagator's Society covering the region of Great Britain and Ireland officially came into existence on the 18th September 1968 at a meeting of interested people at Syon House, Brentford, Middlesex. Behind this announcement and the rather impersonal minutes of the inaugural meeting printed elsewhere in this volume there lies a tale of endeavour which for the record should be told.

An attempt to form a chapter in Britain was made 1960–61 but proved abortive in spite of some hard work by a number of enthusiasts over here. In order to profit by any mistakes which might have been made in the past the reports and correspondence of the earlier effort were re-examined carefully. It was clear that the effort failed because the nursery industry as whole was just not ready for the concept of all that I.P.P.S. stood for. Free interchange of knowledge and experience was not yet generally acceptable and the "locked door" still epitomised the propagation


Author: H.J. Welch

PP: 79

Many members will know that for some time I have been compiling a book on "Mist Propagation". A task of this kind is beyond the capacity of one individual, so an author has to turn for help to so many persons that he becomes merely a kind of editor.

My publisher, being an amateur gardener himself, has pressed for the inclusion of lists of species and varieties, with best dates, percentages rooting, etc., but I have resisted this. There is much published data of this kind which I could have drawn on but, in general, it is so conflicting and inconsistent that no really useful purpose would be served, other than broad conclusions that certain varieties are "easy", certain "medium" and certain "difficult to impossible".

To be scientific an experiment needs to be carried out under conditions so well known that it can be repeated elsewhere, later, by another operator with identical results. But where, in all the welter of recorded results of mist propagation experiments, can there be found data which any of us


Author: J.L. Kitchen

PP: 81

Year round Chrysanthemum growers produce flowers each week of the year by growing to a previously agreed written programme. This programme sets out the details as to when cuttings must be planted and when light or shade should be applied to ensure a regular supply of flowering stems.

The task of the chrysanthemum cutting propagator is to produce the correct quantities of the required varieties each week of the year as dictated by these growers programmes.

This entails putting into the rooting bench in excess of 1 million cuttings each week and removing a similar quantity for despatch to the customers, and our problems are therefore to a large extent organizational.

Cuttings are produced on stock nurseries in the South of England and to obtain the benefit of winter light we produce a large percentage of our sale cuttings in the Canary Islands.

The stock nurseries take cuttings from stock plants by snapping them off at a previously determined length according to the use to which they will


Author: Frank Willard

PP: 84

Although the advances made in recent years by the use of mist techniques, have made it possible to propagate difficult subjects from cuttings, a few notes on my experiences in raising Picea pungens ‘Kosteriana’ by grafting, may still be of interest to those who, for one reason or another still continue the practice of grafting this very beautiful tree.

My first experience of grafting this subject dates back to the early days of the Second World War, when for obvious reasons our supply of this tree abruptly dried up, so if we wanted to maintain a stock we had to go it alone. With this end in view, my boss suggested that I tried my hand at grafting them for ourselves, and in the autumn of 1940 I hurriedly potted up fifty stocks of Picea excelsea.

We had a well established tree of Picea ‘Kosteriana’ in the nursery, and in the following January I was able to collect fifty suitable scions. Without delay I grafted these on the Picea excelsea stocks using the simple side graft and placed them on their


Author: Robert J. Garner

PP: 88

My task today is to take a look at what is now being done in Great Britain and to suggest a part our society might take in increasing the productivity of plant propagation, so leading to wider use and enjoyment of the best possible selections and cultivars.

One's first impression is of complexity. There are well over fifty officially organised authorities doing at least some propagation research, or fundamental scientific work of direct benefit to plant propagation. To simplify I will place these under seven headings.

  1. Research Stations.
  2. Universities.
  3. Botanic Gardens.
  4. Forestry Institutes.
  5. Experimental Horticultural Stations.
  6. Horticultural Colleges.
  7. Commercial and private establishments.

The amount and character of propagation work at these places varies tremendously. Five research stations, Long Ashton, East Malling, John Innes Institute. Glasshouse Crops Research Institute and the Scottish Horticultural Research Institute have extensive programmes. For example, the G.C.R.I. is


Author: Henry Jackson

PP: 91

Cold storage in British nurseries is in most cases a very new technique, particularly where jacket-cooling, as used in Europe for the storage of plant stocks, is concerned.

Having used this system with considerable success since 1965 we feel that it is most important to enquire first how much further we can go in cold storage techniques. Answers to the following questions would considerably extend the economic utilisation of the cold stores.

  1. Hardwood seed has been stored in Europe for twelve months; conifers much longer, up to about 4 years. Is it possible to extend this without losing viability?
  2. What method of storage is most suitable? We have found that mould has developed in containers but surprisingly not in sacks.
  3. What is the optimum temperature for various species — conifers and hardwoods? We have used 32°F here down to 28°F. On the Continent, I believe, temperatures down to —5°C are used.
  4. Humidity is an important factor; 94–96% is normal at Tilhill. Is there any difference in

Author: M.G. Adcock

PP: 92

When Mr. Garner asked me to talk about the problems and priorities for research and experimentation, I was quite concerned about what to say, being a very practical tree and shrub propagator myself. Time and facilities to experiment seem to be the commercial propagator's bugbear.

I think most of the propagation techniques have been, and are still being developed by trial and error on the nursery and sometimes under very poor conditions. It would be a great help, therefore, if a scientific mind, together with laboratory conditions, could assist us with some of the problems of modern and economic plant production. Into this field must come hormones. It is almost impossible to compete in commercial plant production without them. The time to produce a root is sometimes shortened by weeks and the root system produced is far superior as a transplant to cuttings rooted and untreated. I think a larger range of hormones should be available to the propagator than at present exists, in both


Author: Mark T. Wallis

PP: 94

It was five years ago that a day visit to the Pershore College was arranged by the Bristol branch of the Horticultural Trades Association. On that day there were three displays there that were to alter my growing methods more than anyone could have imagined at the time — especially as I was not there! These displays featured
  1. The Bloxer*
  2. Various rooting media.
  3. Capillary beds.

We now have nearly two acres of capillary beds in and out of doors using the N.I.A.E. method, this way we have a tank and ball valve maintaining water level in channels spaced five feet apart, 3 inches below the surface of the sand.

We have had three main problems to solve:—

  1. Removal of rain water. This, we have overcome by laying a land drain beside each bed.
  2. Wind blowing plants over. This, we have only partially solved by caning and then supporting the tops of canes in strips of netlon held between two wires. For lower plants we sometimes use wind-breaks of some sort. This, must be a bigger problem when a

Author: P.M. Robinson

PP: 95

What is the ideal compost?

A compost is an attempt to simulate an ideal rooting medium for a particular plant.

One of the first recorded studies of plant growth and nutrition was by Woodward in 1699 when; on growing vetch, potatoes and mint in water obtained from various sources, he concluded that water was merely a carrier of terrestrial matter.

Our aim as nurserymen is to produce compost suiting the particular plant in question so as to provide the correct amount of water, nutrients and aeration. As a result of this coupled with a favourable climate and light intensity we should achieve maximum plant growth.

The practical qualities of this ideal compost should be:—

  1. cheap to produce,
  2. standardised quality,
  3. good reserve of nutrients,
  4. wide spectrum of usage.

How can we achieve these qualities

In our container department we use only two different mixes of compost, a general purpose compost for the vast range of trees, shrubs and conifers and a special acid compost for ericaceous and allied


Author: A. Bruce Macdonald

PP: 98

Probably, many of you have visited Boskoop, but it is likely that there may be a few members of the Society who have not had this opportunity. Therefore, in view of the day-visit the Society is organising to this area which is renowned for hardy nursery stock production, I thought it would be useful to, firstly, give some background to this area and, secondly, relate briefly four practices on propagation, which I found particularly interesting when visiting the area eighteen months ago.

Boskoop is the most important nursery centre in Holland. It covers a total area of around 1500 acres which is made up of approximately 750 nurseries. The average size for a nursery is about two acres and because of this small size, production is very intensive. The top soil is ideal for nursery stock production and is composed of 34% peat, 28% clay and 38% sand. The soil pH is in the region of 4.5 — 5.5. Despite many advantages the nurserymen face three major problems. These are as follows:

  1. The peaty-

Author: Jill E.K. Cox

PP: 100

First of all, I would like to say how very much I have enjoyed listening to the other speakers today. Each of them has discussed a particular aspect of the science of plant propagation in which he is virtually a specialist. An immense amount of experimentation has been necessary to adapt the results of pure research to practical and commercial technique. One of the most fascinating sidelines in scientific information work can be to look through the published work on a particular crop — such as chrysanthemums — over a period of years and to realize how the use of aids such as plant growth substances, soilless composts, virus-free material and precision equipment for controlling day length and temperature have taken so much of the uncertainty out of raising plants. New developments take place so quickly that one always has an uneasy feeling that one may be missing something of importance or ceasing to be in touch with the latest work; also there sometimes seems to be a great gulf between

Author: G.C. Wills

PP: 54

We are very pleased that you have decided to have your inaugural meeting here at Syon, and we wish you every success in this meeting, and sincerely hope you will enjoy your visit to Syon.

I have been asked to say a few words about the project here; The Gardening Centre is a permanent exhibition for the gardening and horticultural trade. The project is actually run as a company, The Gardening Centre Limited, which was formed in 1965 between the two share-holders — Imperial Chemical Industries Limited through its subsidiary Plant Protection Limited, and the Duke of Northumberland. The two share-holders are in the proportion of 75% Plant Protection, and 25% to the Duke — which amounts to a share capital of 100,000.

During the first phase of the project to opening day, on May 1st 1968, approximately £500,000 have been expended here at Syon. The initial preparations of the grounds entailed major engineering works. A few details of these are that about 4½ miles of paths had to be laid


Author: Brian Humphrey

PP: 106

PETER HUTCHINSON: Can you give me details of the propagation of Mahonia from leaf-bud cuttings, especially Mahonia ‘Charity’?

M. G. ADCOCK: Take them at the end of September on last year's growth with just one node with the leaf bud inside. Bottom heat of 65–70°F is desirable. A compost of 3 sand and 1 peat is best and a rooting hormone should be used after slightly wounding at the bottom. The cutting is reduced to 3 or 4 leaflets and the crown bud can be used if required. We root in boxes and pot on later.

CHAIRMAN: Comparing most cuttings under mist with those in a closed case the mist cuttings row away in the same spring whilst those in the case generally don't grow away until six months later. Mahonia ‘Charity’ and M. japonica root readily.

A MEMBER: But not Mahonia rotundifolia.

PETE DUMMER: The problem is the ripening of the wood. Cuttings of the last named should be taken earlier, in August, when the wood of these is ripe.

CHAIRMAN: The cuttings should be called "leaf mallet" cuttings


Author: Andrew T. Leiser

PP: 117

I would like to talk a little about plant introduction. Although we, in this group, are primarily plant propagators, I think the propagator is as much or perhaps more interested in plant introduction than any other person in the nursery operation. At least working with the propagator and talking to him, it is apparent that most of the propagators are more avid plantsman than many of the people concerned with the producing of saleable plants as an end product. In addition with new plants, new introductions, the selection of clones and cultivars, a great many additional problems come to the plant propagator. We were talking about this as we were coming down last night. The possibility of really interesting cultivars in the genus Eucalyptus introduces one such problem. What do we do when we get them? Nobody has been able to graft them on a commercial scale, nobody has been able to root them except for an occasional plant. This is just one of the challenges that will come from the

Author: Tok Furuta

PP: 128

What is the role of diggers, nippers, or chicken pickers in the production of dormant eye, started eye or two-year rose plants? And is there a relationship between fertilizers and the type of diggers in rose plant production? Many questions such as these should be answered by each producer and consultant because the production of rose plants depends upon the economical functioning of a balanced system of production, and the system functions efficiently only when these questions are adequately considered.

The production process or system currently used for started eye and two-year rose plants may be subdivided into approximately 12 major stages or steps. (For dormant eye plants, a step (9 below) is omitted.) These are:

  1. Preparation of the land.
  2. Gathering, processing and lining out understock cuttings.
  3. Gathering, processing and storing scion wood.
  4. Providing cultural care for the growth of the understock prior to budding of scion variety.
  5. Budding.
  6. Cultural practices to assure union of bud.
  7. Removal

Author: Herbert C. Swim

PP: 130

I wish to make clear at the onset that I make no claim to original discovery with respect to any of the experiences I shall relate. I deal with them only because they seem, from my point of view, to have been the more useful of the observations I've made over the years and that come to mind now.

In looking back, it seems to me that among the more significant of my early discoveries was one that made itself apparent after a series of frustrating experiences associated with failure.

My first experiences in the making of exploratory rose crosses, while not entirely failures, were sufficiently so as to make it appear expedient to evaluate the factors involved in the failures and further, to try to give them a rating as to importance.

In casting about for some apt title for this procedure (entirely for my own use I have thought in terms of a phrase which is meaningful to me, "A Priority of Limiting Factors."

I shall try to illustrate what I mean by using some actual experiences and telling of them in the


Author: Raymond F. Hasek

PP: 133

Much has been written about scion-rootstock relationships in commercial rose plant production. However, many instances of peculiar growth patterns or responses occurring in greenhouse cut flower plantings have been often talked about in the trade yet seldom mentioned in print. Entirely different growth requirements exist between outdoor roses grown for the home garden and greenhouse plants grown for cut flower production. Outdoor rose understocks should have such characteristics as drought resistance, cold resistance, exhibit good dormancy during the winter to prevent scion or understock growth and finally be easy to bud. In the greenhouse the rootstocks are pampered since they are usually subjected to very little drought or cold stress. Production of cut flowers goes on all year round; therefore, optimum growing conditions are maintained to assure continued growth and activity of the understock during the winter as well as the summer months.

At present, by far the most popular


Author: Walter M. Mertz

PP: 136

In the propagation of field grown roses the propagator's prime role is to physically and successfully join a selected scion or clone with a preferred rootstock so that a viable plant combining the best attributes of the two components results.

The techniques of rose propagation are basically simple, highly standardized, and for the most part are quite successfully accomplished by most of the rose growing firms. However, in California today it appears that the greatest emphasis, and the major problem solving requirements, center not so much on the art of propagation, as such, but rather in the field of production.

The basic difference between propagation and production is chiefly one of dimension. The production function, as I will define it for today's discussion, is the art of propagation performed on a large or massive scale. Production of field grown roses goes far beyond the individual propagator. Field production is chiefly the responsibility of a highly qualified professional production staff


Author: John Rodebaugh

PP: 143

Success in horticulture depends directly upon a grower's ability to maintain his plant material in a disease-free condition. Good growth depends upon many factors being in proper balance, but if we were to single out any single factor as being the most important, it might be the health of the plant the grower starts with. A quality plant never develops from a diseased seed or an infected cutting or liner.

The importance of keeping plants healthy has long been recognized. One of the first papers on this subject was published in 1723. Since that time, much progress has been made in this field, but there continues to be room for improvement. The key to any program depends upon knowing the life cycle of the pathogens that you are trying to control and then developing the necessary sanitary facilities to keep these pathogens from the plant's environment. This goes back to the old phrase often used by Dr. Baker, which is; "don't fight 'em. eliminate 'em".

One of the best reviews on sanitation in


Author: George Nyland

PP: 146

Plants that have been propagated vegetatively for many years are usually infected with one or more viruses. This is a principle of plant pathology. Not all viruses cause conspicuous disease symptoms in plants they infect; some may not cause any detectable damage and in some cases they may perhaps even be desired by man. Examples of the use of viruses, often unknowingly, to make desired modifications of plant growth are certain variegations in ornamentals, shortened internodes, and dwarfing in some fruit-tree varieties, and recumbent or weeping growth habits of some woody ornamentals. In most cases, however, viruses are harmful to plants, and clean stock is preferable to diseased stock.

The need for virus-clean stock.—When damage caused by viruses is not conspicuous, losses are often difficult to ascertain. A moderate reduction in fruit set, fruit size, or tree or vine size may easily go unnoticed or be attributed to cultural or environmental factors, especially if all plants in a


Author: Stanley M. Mather

PP: 149

Nursery stock is a primary means by which plant pests may be introduced. Even though recognized as such and given close attention over the years, serious virus diseases and other pests have been perpetuated unwittingly by man through his propagation of plants. The exclusion of plant pests from nursery stock propagating sources is not an easy task. Close coordination between research, regulatory and industry activities is needed if we are to succeed. Index testing for virus diseases, laboratory techniques for the detection of nematodes, and eradicative treatments have and are being developed. These improved procedures will permit nurserymen to maintain plant propagative sources for the production of high quality nursery stock.

Regulatory and industry activities in past years have been directed toward reducing pest infestation through visual observation of plants and by quarantine restrictions. Experience has shown that certain plant pests can be present that were either not recognizable


Author: Don Luvisi

PP: 158

"Why do we have a certification program?" "How successful has it been?" These questions can be answered in many different ways depending on what commodity is chosen. On stone fruits we are concerned with increased efficiency of propagation. It has definitely resulted in greater efficiency for the nurseryman. However, have we improved the variety, actually increased the life of the tree or orchard, increased the yield, maturity, or fruit quality? We know that in citrus the elimination of virulent viruses causing low productivity or tree death is an important part of the program. The certification program for wine grapes has been successful while table grapes have lagged. When we get into ornamentals what are the advantages or disadvantages of certification? Is it economical increases in efficiency through higher stands of plants for the nurseryman or is it longer life, more flowers, more or less desirable foliage for the consumer?

Author: David N. Clark

PP: 57

In this short illustrated talk, I will not be able to give a comprehensive survey of the subject but a series of disjointed facts. I do, however, want to pin-point huge differences that exist from nursery to nursery and suggest a few ways in which British Chapter of the I.P.P.S. could be of benefit to the industry. Although today I am concentrating on getting the plant into the pot I would like to point out that a great deal of study is needed on the movement and handling of plants in containers within the propagation department. This is a difficult subject to tackle in existing units which frequently consist of old glasshouses and narrow paths but it is one which should be given primary consideration in the design of any future propagation unit.

Before getting too deeply involved in my subject, could I clarify that both potting and containerizing refers to the same process, the former being used more widely in this country, while the word ‘containerizing’ has been introduced from


Author: John R. Wynne

PP: 159

In the spring of 1955 it was suggested to us by staff members of the California Department of Agriculture and the U. S. Department of Agriculture in Sacramento that some of the problems encountered in the successful propagation of deciduous nursery stock were due to virus-infected scions and/or rootstocks. We were very interested in their findings, and their proposal to conduct tests with them at our growing grounds. In the first year of cooperating with these men we were impressed by preliminary evidence that viruses were an important factor affecting good bud stands and in producing vigorous and uniform nursery stock.

In the early stages of developing the Certification and Registration Program, Department of Agriculture members visually inspected bud sources in selected grower orchards. Visual inspections culled out the bud-source trees most severely infected with ringspot or other viruses.

At the time, bud lots were mingled on a variety basis, and no effort was made to ascertain the


Author: Roger B. Jensen

PP: 162

Initially, I want to thank the International Plant Propagator's Society for this invitation to participate in your annual meeting. Being a non-scientific degreed nurseryman, I feel rather inadequate addressing you.

The California Citrus Certification Program was initiated more than 10 years ago and not a single certified citrus tree has been dug and sold by a commercial nurseryman to date. No apologies need be given for this fact in my opinion; perhaps compliments are in order. The California Citrus Nurserymen are operating under an interim Registration Program. I believe that the citrus industry would assess this program affirmatively.

Within the next two years however, commercial digging of certified trees will commence. When sufficient volume is available, the citrus nursery industry will be required to evaluate the interim Registration Program and decide whether to terminate or continue the program.

At this point potential danger does exist in cutting excessive buds from a relatively


Author: Herbert C. Swim

PP: 164

We who are involved in a commercial breeding program for roses must be conscious of those factors which hinder the ever-widening use of roses. We also must be thinking about those qualities that may stimulate new interest among those who may or do use roses. All rose breeders are especially sensitive to such spectacular factors as a "new color break" because they know it will attract attention from those who already like roses.

We have become increasingly conscious in the last few years of a phrase which we now know is being uttered too often. The phrase goes something like this: "I don't like roses because they are too much trouble." When we get this clarified, we find that "trouble" means spraying for various types of pests, in about 90% or more cases. It seems dubious that the plant breeder can do much about breeding roses resistant to insect pests, but it certainly is feasible for us to consider and hope for results in breeding for disease resistance.

We have become


Author: J.L. Paul, A.T Leiser

PP: 170


Research in plant propagation in the past 35–40 years has been dominated by uses of auxins (11) and mist (13). L. H. Bailey, in the 1920 edition of his classic Nursery Manual, gave scant attention to the role of the rooting medium in the process of root initiation. Little attention has been given to the chemical nature of the rooting medium. An early study by Hitchcock et. al. (4,5) found that rooting was affected by pH of the medium. Laurie and Chadwick (6) reported differences in rooting between peat, peat-sand and sand media. Media influenced percentage rooting, number and length of roots and in certain species, position of roots on the stem. Although the media differed in a number of properties, quantitative measurements were not given. More recently Raabe and Vlamis (10) showed the effects of sodium-calcium ratios of peats on rooting of chrysanthemum. Paul and Smith (9) studied rooting of chrysanthemum in peats of varying exchangeable calcium-hydrogen content. The


Author: Robert D. Raabe

PP: 181

Red root, a disease of chrysanthemum cuttings, first appeared at a nursery following the change of water supply from a well about 400 feet deep to a well about 800 feet deep. A comparison of analyses of water from the two wells is given in the following table:

Author: J.L. Paul

PP: 183

The concentration and composition of dissolved mineral salts in irrigation water determine the water quality. Agricultural scientists have developed classifications of irrigation waters based on kind and quantity of salts contained in the waters. The principal indices for classification are total salt content, proportion of sodium and boron concentration. These standards apply mainly to field conditions, but it is questionable that the same criteria are suitable for the special conditions of mist propagation. To gain a more thorough understanding of environmental factors which effect rooting it seems appropriate that water quality be studied for conditions of mist propagation.

The major cations contained in natural waters are sodium (Na), calcium (Ca) and magnesium (Mg). Major anions are chloride (Cl), sulfate (So4) and bicarbonate (HCO3). The cation of chief concern is sodium. Waters with a high sodium hazard rating are unsuitable for irrigating purposes since they can cause alkali


Author: Duane Sherwood

PP: 187

There is a high demand for Colorado Spruce plants that are all blue. Colorado spruce are generally fuller with a better shape than Koster blue spruce, the old standby.

Presently, most Colorado spruce plants are raised from seed. If the seed is collected from blue parents, the offspring may vary from 10% to 60% with 20% blues considered a very good result.

Grafting is frequently used for strains of Colorado blue spruce such as Koster blue spruce. Grafting has advantages of generally quicker results and uniform plants. Many people feel that a seedling understock will give a better plant. The disadvantages are that it takes experienced help to do this grafting and this experience help is usually hard to get. Conditions where these grafted plants are kept are also quite critical.

The next way of reproducing plants is by cuttings. In talking to most nurserymen, Colorado spruce are very difficult to root from cuttings, and when they do root, roots are typically poor and claims are that


Author: Ralph Shugert

PP: 188

Prior to presenting this paper. I would ask your indulgence for a moment, and extend the deep appreciation of myself, and my wife Shirley, for all of the courtesies extended to us during our visit in Fresno. Last December the Eastern Region had their 17th annual meeting in Mobile, Alabama, and the southern hospitality was outstanding… certainly the western hospitality during your 9th annual meeting is also heartwarming, and very pleasing. My fervent thanks to all of you.

In discussing such a wide embracing topic as the sexual propagation of woody plants, I have decided to make some general observations, and explain some of the techniques that are employed at Plumfield Nurseries, Fremont, Nebraska. In glancing over our shoulder through the Proceedings of past meetings of the Society, there have been many words pertinent to seedling propagation. One of the very finest reviews of this topic was a paper presented at last year's Eastern Region meeting by Dr. Steve O'Rourke. I quote from his


Author: Ralph Pinkus

PP: 193

First, we should take a look at the philosophy of operating a garden center or retail nursery. It is our job to supply plants for local use obtained from local and distant sources. We contact the gardening public in a residential area and are therefore customer oriented. We have large colorful displays of seasonal items to tempt customers.

We greet all customers on arrival and encourage them to browse. For stock we carry a wide variety of plants including:
          Bedding plants
          Herbs and vegetable plants
          Ground cover plants
          Water plants
          Hanging baskets
          Espalier plants
          Summer flowering tropicals
          Small trees
          Large balled trees to $500 size
          Azaleas and rhododendrons
          Ferns, outdoor and indoor
          Fruit trees
          House plants
          Large indoor plants to 16' high for offices and banks
          Pot mums and other seasonal potted plants
          Tubbed and potted plant specimens for house and patio

All plants are kept in a healthy condition by using constant feed, spraying


Author: W.A. Humphrey

PP: 199

The use of selective herbicides for weed control in container-grown woody ornamental plants is in itself a new practice. The increased use of herbicides has come about with the development of more selective pre-emergent herbicides. As nurserymen, you are well aware of the high cost of controlling weeds by hand in containers. It's a job that never ends. Often inadvertently you produce your own weed seed and the job needs to be done repeatedly. In addition, the number of plants grown which have thorns or spines makes for a very difficult weeding situation. In hand weeding, rarely is a complete weeding job accomplished.

A number of field studies have been conducted looking at two aspects of the use of selective herbicides for weed control in container-grown plants. The first question is tolerance of woody ornamentals to herbicides, the second is weed control. Several extension workers and nurseries have cooperated in these tests. Extension workers involved include Jim Breece, Clyde


Author: Adrian Bloom

PP: 61

First of all I must apologise for not being able to be present at this inaugural meeting to form a British Chapter of the International Plant Propagators' Society. I am fully in agreement with its aims and principles and therefore hope that my talk will have some useful contribution to the day's proceedings.

Before going into the actual part of herbaceous propagation itself I should like to explain the position we at Bressingham are trying to fill in the horticultural industry and the trends we see from our vantage point in Norfolk.

Most nurserymen would agree I think that the general trend has been towards roses, trees and shrubs over the past few years. In consequence most general nurseries have tended to concentrate on these lines and as herbaceous plants were always the last to be planted, and usually were the most uneconomic, due to high labour costs and a low profit margin, then it often followed that herbaceous were the first to be dropped. If not dropped altogether then they were bought


Author: F.S. Morishita

PP: 202

Systemics are not new as P-40 (sodium selenate) was used in the 1940's on various greenhouse crops. Since that time, systemic organo-phosphorus compounds were developed in the 1950's. These were OMPA, Systox® and phosphamidon which were quite effective against aphids and mites. However, with resistance building up against these materials, other systemics such as Thimet® and Di-syston® were developed. In the late 50's and early 60's several others appeared on the scene and soon showed promise for pests other than aphids and mites. One of the first things these materials were tried on was the flower thrips on various flowering crops. In 1961, Cygon®, Thimet and Di-syston were tried on gladiolus and proved to be very successful in controlling the flower thrips. These materials were next tried in 1962 on field-grown roses for control of thrips and the results were just as good as on the gladiolus. Along with these, two relatives of Cygon, AC43064 and AC47031, were incorporated in the tests

Author: Robert D. Raabe

PP: 203

The development of systemic pesticides has opened a new era in agriculture. Some systemic insecticides are now available and more are in the process of being tested. Systemic fungicides are in the testing stages and only one has been released to date. The development of systemic fungicides has been slower than that of the systemic insecticides, partly because with the insecticides, the chemical must be effective against an animal system while moving through a plant system. Since fungi are plants, systemic fungicides must be effective against a plant system while moving through a plant system. Though this presents difficulties in finding materials which will be toxic to some plants and not toxic to others, such materials when found have the advantage that they are less likely to be toxic to animals (including man) than the systemic insecticides.

The first group of systemic fungicides to be developed belong to a group of chemicals known as oxathiins. These were first obtained


Author: Roy M. Sachs

PP: 206

In the past decade two kinds of research, one concerning naturally occurring growth regulators and the other synthetic substances discovered in screening programs, have yielded substantial advances in our ability to control plant development.

The work reviewed below is not necessarily "new", but, since there appears to be a 10–20 year lag between discovery and true application of growth regulators, it may be important to review the synthetic compounds made available over the past two decades. Present studies with naturally occurring compounds are more likely to sound "new" since they are still in the laboratory stage. However, they suggest outstanding opportunities for the development of additional chemicals of economic importance and will be discussed first.

  1. Naturally Occurring Compounds

    1. Abscisic acid (and related substances)

There is little question that the isolation of abscisic acid (ABA, abscisin II, dormin) from many different plants is having the same impact on our


Author: H.A.J. Hoitink

PP: 238

Plant diseases affect the lives and well-being of so many individuals that the most popular interest in them concerns the means by which they may be prevented. Control of disease is the ultimate purpose of a distinct science of plant pathology. Many disease control practices originated by empirical "cut-and-try methods" long before the true nature of disease was understood.

Disease control measures may be divided into two major groups: 1) prophylaxis and 2) immunization. Prophylaxis implies the protection of the host from exposure to the pathogen, from infection or from the environmental factors favorable to disease development. Immunization refers to improvement of resistance of the host to infection and to disease development.

In the propagation of plant material from cuttings or tissue cultures, prophylaxis is the major approach to disease control since comparatively little is known about disease resistance in ornamentals. Disease control in this area, therefore, can be


Author: R. Kenneth Horst

PP: 241

It is fashionable today in modern day research (both animal and plant investigations) to relate research projects in some manner to tissue culture. Most of the interest in tissue culture has centered around the increased concern of mankind for the answers to the complex question of the cause and cure of cancer. Cancer or malignant tumors is one of the most feared diseases of man. Tissue culture has served as a means of studying the ways in which tumor-type growths develop and ways in which these types of growths can be retarded or inhibited. Tumor cells, on dividing, produce tumor cells regardless of whether one is dealing with plant or animal cells; however, the conversion to normal tissue growth from callus-type tissue growth has been done with certain plant tissues (4, 10, 11). It is the implication and importance of this type of technique which we want to consider in relation to the propagation of plant materials.

We want first to define what we mean when we talk about plant tissue


Author: L.V. Edgington, Marten Snel

PP: 244

A chemical which is taken up by a plant and transported within the plant may be considered as systemic. If the chemical controls diseases of the plant caused by fungi, bacteria, viruses, or mycoplasma, we call it a systemic fungicide, systemic bactericide, etc.

Are such compounds for disease control available? Certainly the entomologists can control insects with systemic insecticides like phorate and dimethoate. The physiologists can supply us with a host of systemic herbicides. Where do we, as plant pathologists, fit in this development of systemic compounds to control the pathogens?

I must admit we are far in arrears of the entomologist and physiologist but developments are rapidly emerging. The egg has hatched!

Prior to 1966 our only meager achievement was in antibiotics such as actidione and blasticidin S. The former controls several diseases such as hawthorne leaf spot caused by a fungus. A single application of 1 part per million in late June will control this disease, even though


Author: Charles F. Scheer Jr

PP: 248

Repeated foliar insecticide sprays have been necessary to control aphids on newly rooted rhododendrons which are grown on Long Island from January to June in greenhouses. This study was designed to determine if granular systemic insecticides applied after planting would effectively control aphids from the time of planting to removal from the greenhouse.

Author: Hubert L.J. Rhodes

PP: 252

There are some well known facts about juvenility that have a particular bearing on the propagation of woody plants from cuttings and by other asexual methods: (1) that juvenile shoots generally root very readily as cuttings, even in those species and cultivars in which the adult phase can be rooted only with great difficulty; (2) that adventitious shoots formed on roots normally resemble the juvenile shoots of young seedlings; (3) that a juvenile capacity persists in the basal region of the stem of a plant grown from seed or from cuttings of roots or juvenile shoots, making possible the establishment of a permanent source of juvenile propagating material through stooling; and (4) that the juvenile base may become lost through the use of adult shoots for propagating material, at least in some plants under some conditions. In persistent juvenile forms on the other hand, the juvenile zone is enlarged, so that development is arrested in a juvenile or semi-juvenile state for a longer part of

Author: Joe Cesarini

PP: 255

In the last few decades, smaller homes and properties have become very popular; likewise the interest in low growing and dwarf plants has increased due to a desire to create a scale proportionate to existing surroundings. Oriental gardens have also had a large influence on modern landscaping. There are several people who have gotten an early start in collecting these dwarf conifers and have arranged them in beautiful gardens which the public is welcome to visit. With this increased interest, a greater demand for dwarf material exists; therefore the capability to satisfy the market rests with the propagators and nurserymen.

When a new collector gets the plant fever, the first plant he usually buys is a weeping hemlock. The Weeping Canadian Hemlock reproduces fairly true from seed and in some cases, even better. Viable seeds are hard to come by. The germination is very poor and erratic. This plant can also be propagated from cutting by using Hormodin #3 on the current year's growth and


Author: Roy M. Nordine

PP: 258

What is a dwarf conifer? There are several definitions of this term and all are valid. The accepted one includes all low and slow growing evergreens. Since there are exceptions to all rules many of the low growing junipers are not slow growing. Several forms of prostrate type Taxus are also rapid growing. A great many of the slow growing conifers continue this manner of growth until they are large or much larger than what we accept as a dwarf conifer.

The customer, the consumer of our products, will define a dwarf conifer as any plant that will remain small. How small he doesn't know, except he is concerned with a foundation planting that will not eventually hide his house, nor block out the entrance to the house.

Another definition is a natural one—what does nature define as a dwarf conifer? Mugho Pines in their native state range from low, nearly prostrate plants to some 30 feet tall, while the adjacent Austrian Pines will grow to 120 to 150 feet high. Nature has defined Mugho Pines


Author: Robert J. Hares

PP: 67

Although we have been propagating birch by cuttings for only two seasons, I thought the knowledge we have gained from this method might be of some interest to you. From our results, it has been shown that the two most important aspects of this method are: (1) the source of the cuttings, and (2) timing of taking the cuttings.
  1. The source of the Cuttings.

  2.      The condition of the plant from which the cuttings are taken makes all the difference to the success of the operation. The plant must be healthy and vigorous, and if extension growth is limited, the results will be poor.
  3. Timing.

  4.      This varies widely according to the species, and the season, but as yet we haven't taken any cuttings here before the 15th July, although with certain types, earlier propagation might be advantageous. Our most successful batches were with Betula papyrifera and Betula pendula ‘Youngii’ taken on the 18th August and 1st September. With Betula papyrifera it seems possible to take cuttings over a long period because

Author: Albert G. Johnson, Scott S. Pauley

PP: 265

This report on the recovery of dwarf seedlings from seed collected from pine witches'-brooms goes back to 1946 and an initial observation of small but mature and apparently otherwise normal cones borne by a witches'-broom in a jack pine (Pinus banksiana Lamb.) tree in Douglas County, Wisconsin. The broom was large, about six feet in diameter and terminal in position.

Witches'-brooms, while not common in pines, are such conspicuous objects as to be frequently reported. They have been observed in nearly all our North American species. They are also known to occur in this country on the European Scot's pine (Pinus sylvestris L.) and Austrian pine (P. nigra Arn.) and are reported frequently in European literature.

A small quantity of seed obtained from a sample of cones of the above tree was planted in 1950. The surviving population at the end of the growing season consisted of four seedlings. Three of the trees were normal appearing one year jack pines, but the fourth was much dwarfed resembling


Author: Donald T. Krizek, William A. Bailey, Herschel H. Klueter, Henry

PP: 273


The plant propagator has long been interested in ways to accelerate seedling development through proper manipulation of the environment. A number of researchers and commercial growers have reported on this subject in the Proceedings of the Plant Propagators' Society during the past seventeen years.

Conditions during germination and early seedling development exert a profound influence on the subsequent fate of the plant. Methods for improving these conditions, therefore, are of considerable importance to the propagator.

The recent development of plant growth chambers and other controlled-environment facilities affords today's grower a unique opportunity to control environmental factors previously neglected or poorly controlled.

In the past, controlled environment chambers were only available to the researchers (20). Although this is no longer the case (6, 9, 19), the literature on controlled-environment effects is still largely confined to non-economic plants. To fill


Author: J.M. Molnar, W.A. Cumming

PP: 281


The propagation of horticultural plants is an important aspect of the nursery and bedding plant industry. Many species and cultivars are difficult or impossible to propagate from cuttings. Any technique that will increase the number of species which may be propagated, or reduce the time and space used for propagation will assist the industry.

The use of CO2 may be helpful in propagation. Wittwer (5) and Voipio (4) reported strong root development of plants grown in an atmosphere enriched with CO2. Carpenter (1) found that lettuce and chrysanthemum grown in a mist of carbonated water weighed three times more than plants from the check. At Morden, we found that when young vegetables and ornamental plants were grown in CO2 enriched atmospheres a superior root system was developed. These observation led us to our propagation experiments.


Author: P.C. Kozel

PP: 288

We in horticulture are the potential beneficiary of a great deal of research being conducted in areas of biochemistry, chemistry, physics and plant physiology. Outstanding scientists, who are very often not plantsmen, have demonstrated that chemicals can profoundly effect plant growth. Today, for example, chemicals exist which can
     — prevent, delay, or stimulate seed germiniation
     — retard or accelerate vegetative growth
     — increase or decrease lateral branching
     — chemically prune plants (roots and shoots)
     — prevent, delay, or accelerate flowering
     — inhibit or promote fruit formation
     — defoliate plants
     — substitute for cold temperatures or long days etc.,
          the list is very long
It is our responsibility in horticulture to be aware of the information gained from research in other areas of science and apply it to current needs of our industry. This concept is the essence of our plant growth regulator program at The Ohio State University.

One important concept must be understood concerning the use of


Author: John A. Wott, H.B. Tukey Jr

PP: 292


The most important method of propagating ornamental shrubs — deciduous as well as broad and narrow-leafed types of evergreens — is by cuttings (Hartmann and Kester, 1968). Likewise, many of the florist crops such as carnations, poinsettias, and chrysanthemums are propagated vegetatively by cuttings. Propagation by cuttings is simple, inexpensive, the techniques are easy to learn; many plants can be started in a limited amount of space, and genetic preservation of a desirable plant race is possible (Wott, 1966).

Water conservation is of prime importance to the cuttings during propagation and the development of mist propagation techniques greatly aided the propagation industry (Snyder, 1965). However, symptoms characteristic of nutrient deficiencies due to mineral nutrients leached from the cuttings or to nutrient dilution within the growing cuttings have been reported (Snyder, 1954; Sharpe, 1955; Good and Tukey, 1966). Nutrients can be applied to cuttings during


Author: Malcolm M. McLean

PP: 303

This presentation is intended to convey the past and present objectives and ideas in using tubes for tree propagation. I hope that the inclusion of some of the particular problems encountered so far in Ontario will provoke discussion and thus generate new thoughts which can be applied in future development of the basic technique.

The following rather cursory introduction is to set the scene, so to speak, indicating how the tube came to be used as an integral part of Ontario's expanding forest regeneration program.

In brief outline, the tube-grown tree is one which has been established by sowing seed in a small tube containing soil. The plant must be tended and protected until it has developed to a stage where, it is judged, it may be transplanted with a reasonable hope of survival and satisfactory subsequent development. This paper deals with the tubes being used by the Ontario Department of Lands and Forests as part of its reforestation program. These tubes are three inches long and


Author: W.A. Cumming

PP: 309

Introduction — There is nothing profoundly new in the evidence which has been collected over a three year period and is presented in this paper. Propagators have argued the pros and cons of trimming cuttings for many years and indeed some of you have already discontinued this laborious and meticulous process. Trimming was originally necessary to reduce water loss by transpiration from the leaves and thus prevent wilting. Although modern techniques of maintaining high humidity make this reduction of leaf surface unnecessary, a search of the literature failed to reveal a single paper or mention of any evidence that the trimming of cuttings might be superfluous.

Dr. S. H. Nelson, Head of the Department of Horticulture at the University of Saskatchewan, has some interesting unpublished data on removing different percentages of the leaves from cuttings. This work was carried out at Ottawa in conjunction with experiments on the spacing of cuttings. In general, his results are in agreement with


Author: Paul E. Read

PP: 312


The use of chemicals to modify plant growth and development is rapidly becoming one of the most stimulating and exciting fields in horticulture. Chemicals have been found which will hasten or delay flowering. cause blooms to set fruit or to abscise, promote rooting of cuttings, kill undesirable plants and plant pests, and a host of other uses beneficial to the plantsman. B-Nine (N-dimethyl amino succinamic acid), a chemical which is commercially used as a growth retardant for florist crops, has been demonstrated to increase flowering and fruiting of tomatoes when applied at early stages of growth, while the same chemical can be used to eliminate bloom on the same plants when applied to the flower buds (2).

B-Nine was demonstrated to increase tuberous root formation (Fig. 1) when applied as a foliar spray to rooted dahlia cuttings. Cuttings taken from such treated plants rooted more readily than those from untreated plants or plants treated with Cycocel (2-chloroethyl


Author: Alfred J. Fordham

PP: 319

Cedrus deodara, commonly known as the Deodar, Indian or Himalayan Cedar, is a tree native to the Himalayan Mountains from Nepal to Afghanistan at altitudes of 1200 meters or higher. Although perhaps the most striking, it has been considered the least hardy of the true cedars. Rehder lists it as a Zone 7 plant while Den Ouden and Boom, in their recent Manual of Cultivated Conifers, speak of it as being not quite hardy in Western Europe. L. H. Bailey considered it to be by far the best conifer for planting on the Pacific slope and one of the most popular conifers planted in Southern California. It is also widely used throughout the Gulf States. Through the years deodar cedars have been tested repeatedly for hardiness at the Arnold Arboretum but have always failed to survive for they lacked the ability to withstand the winters.

In 1961 two one-year-old grafted plants of a cultivar named Cedrus deodara ‘Kashmir’ were given to the Arnold Arboretum and since that time they have proven hardy.


Author: Dave Patterson

PP: 323

The Question Box session convened at 7:40 p.m. in the Ontario Room. Mr. David Patterson was moderator.

DAVE PATTERSON MODERATOR: I'm delighted so many are here so early. I worried for two days that we wouldn't have enough questions; now I'm worried that we have so many we won't be able to cover them all. Without introductions of any kind I'm going to start right off with an easy question. What is the procedure for rooting Pinus strobus?

SID WAXMAN: I'm not going to give any recommendations as such but there are individual trees from which cuttings can be rooted. I know of one and have rooted cuttings taken in May wounded and treated with Hormodin 3 and Captan and placed in mist. They did take quite a while to root.

JOHN ROLLER: There are quite a few individual white pines that will root using Hormodin 2, mist and sand. I've noticed two Tanyosho Pines that in grafting it with moist peat around it, roots came out as quickly as the union is made. These were taken in early June from mature growth.


Author: Robert J. Hares

PP: 68

I believe that the propagation of French Lilacs under mist is a method that has been neglected. It is true that their propagation comes at an extremely busy time of the year, but the results can justify the trouble taken.

Timing of the propagation and the condition of the stock plants are most important, but the timing is the most important factor.

Usually the best time is from the middle to the end of April in this part of the country, and a very close watch must be kept on the stock plants. If the cuttings are taken too early, damping off in the mist will be excessive. The shoots must be taken at a stage when there are one or two pairs of well developed leaves, and when the shoot is making active extension growth. It is important that the cuttings are taken before the terminal bud is visible, and there is only a period of 7 to 10 days when hybrid lilac cuttings can be successfully taken. If taken after this period, rooting is slow and erratic. Particularly with this very soft type


Author: A.R. Knauer

PP: 334

The small public garden offers to the people of the community which it serves the opportunity to select plants for their own use with relative assurance of success in that area. Selection can be done on a discriminating basis for the merits of the plant are evident even to the casual observer — the shortcomings perhaps only to those with a more critical eye. To the nurseryman, the plant hybridist, the introducer of new or unusual plant, the garden store operator and the mail order merchandiser, the small public garden offers an opportunity for advertising and promotion at relatively low cost. The cost production of a half dozen Cotoneaster congesta, pro-rated on a life span of twenty years or more (given an amicable climate), amounts to darn cheap advertising when you consider that perhaps a million or more people will look at it during this period.

There are a number of large well funded gardens across the United States and Canada which do an excellent job of displaying plants in


Author: James S. Wells

PP: 339

The other day I was quietly eating my lunch when the phone rang. It was Dave Dugan requesting that I give this talk. It was my own fault, of course, because I had written to him suggesting that he was producing a mystery program. You would have thought after all these years that I would have learned to keep my mouth shut.

You may know by now that a British Region of I.P.P.S. has come into being and that we are to discuss this in the business meeting. As a prelude Dave thought it would be a good idea for me to try to tell you what a British propagator is. I must own this request set me back momentarily and when he went on to add that I was the only British propagator that many of the members had ever met, I was quite frankly stumped. So in order to get off the phone and finish my lunch, I agreed.

My first reaction was, of course, that there is no difference and fundamentally this is true. At the recent meeting which I had the pleasure of attending in England it was abundantly


Author: S.H. Nelson

PP: 343


The problem of scion varieties failing to make satisfactory growth when budded or grafted to certain rootstocks has been confronting nurserymen and growers for years. Grafting would seem to date back to antiquity. The early heterogenous combinations attempted were recognized as unsuitable in pre-biblical days (212) and also mentioned in early Chinese writings (43). The phenomenon of incompatibility, also known by the synonyms of uncongeniality or lack of affinity, has been common in a number of genera but more publicity has been given to fruiting trees, possibly because of the economic importance.

This survey was undertaken by the author for the International Plant Propagators' Society, Eastern Region, and partly financed by the organization. It was initiated by canvassing the membership, in both the Eastern and Western Regions. As shown in the bibliography, many usable returns were obtained, but the survey was supplemented to a large extent by a search of the


Author: P.C.R. Dummer

PP: 69

The stocks are lifted from the seed bed in the fall of the second year. The sizes most suitable for grafting stocks are between 3 – 5 mm.


Potting should be done using a 3½ ins. clay pot which should have previously been crocked using a ¾ ins. Straight gravel. The compost should be a fairly light open mix, we at Hillier's use 7 peat, 4 loam, and 2 parts coarse potting grit to which has been added 4 oz. of John Innes base manure to each bushel of compost. No ramming is required so long as a few taps on the bench and the use of the thumbs are employed when potting.

After potting they should be stood down on a well drained open plunge. A covering of leaves or peat should be given to protect the clay pots from frost damage, also the size of the plunge should be banked-up either with sand or ashes, this not only protects the outside rows of pots from frost but also helps to steady them when personnel and trucks go up and down the paths of the plunges.


Frequent spraying


Author: John Emery

PP: 72

Requirements:— Preferably a glasshouse, with benches fitted with soil-warming and overhead mist. Alternatively, a range of double-glazed cold frames may be used, either on their own, or in conjunction with the glasshouse.

A ready available supply of potting compost, either "John Innes", "Levington", or the "U. C. Soilless Composts"

I use "U. C. Mix D", to which is added slightly more lime for the general line of shrubs and ¼ in. shingle at a ratio of 1 part shingle to 3 parts U.C. mix. A medium grade of sphagnum peat is used throughout.

The jiffy pot used is No. 425, size 2½ ins. round × 3 ins. deep, the extra depth is an asset to shrub production.

Last but not least, a good supply of cutting material, which alas, is not readily available on most nurseries. It is a good idea and I feel, a must, if one is contemplating producing large numbers of shrubs in variety to have a "Stock Block" planted in the vicinity of the greenhouse or frameyard, with the required number of plants of each


Author: P.D.A. McMillan Browse

PP: 74

For those subjects which will respond, the propagation of plants from hardwood cuttings is undoubtedly the cheapest and most effective system of production. But the technique depends on a satisfactory level of productivity, otherwise resources are wasted by having to bulk up by other propagation systems. The object of this paper is to show how a technique can be developed for taking hardwood cuttings so that maximum productivity is achieved — for every cutting made and inserted represents expenditure and it is therefore important that the highest possible number regenerate in order to reduce costs to a minimum per liner produced. With ‘easy’ subjects this usually presents no problem but it is with those subjects which show only variable or marginal success that attention to detail can produce an economic system.

To do this it is necessary to look at all the factors affecting the regeneration of plants from hardwood cuttings and by isolating each, determine its most