Volume 16

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Author: C.P. Teague

PP: 50

There are many methods of budding and grafting in use today and tip-grafting is just one method that adapts itself quite well to avocado propagation. Tip-grafting is nothing new to most propagators so I will not get involved in minute details unless someone wishes to know something specific.

We grow avocado seed in clean soil, in pots on benches. By doing this we avoid most of the fungi problems and have a minimum of trouble. Cleanliness is very important as the seed are forced under high heat and humidity. We prefer to harvest the fruit before it drops so the seed does not become contaminated on the ground. Tip-grafting of avocados was first done commercially by Walter Beck of Fallbrook, Calif. around 1946–48. Shortly thereafter, many growers and nurserymen, including myself, adopted the method. It is a guess that 75% or more of all commercial avocado trees grown today are tip-grafted by the method I will describe.

In our own nursery in Corona, Calif. we generally use the same


Author: George S. Oki

PP: 93

Webster's Collegiate Dictionary still defines a "green-house" as; a "glassed enclosure used for the cultivation or protection of tender plants." In the last decade, a greenhouse has taken on the sophisticated title as an "enclosure for environmental control."

While it is true in days past that heat was the primary element added to protect and cultivate tender plants in green-houses, very little was done toward cooling. The only control for high temperature was accomplished by ridge and side ventilators.

With the advent of "pad and fan" cooling the entire concept of greenhouses was altered. Continuous ridge and furrow type houses became a standard. With temperature and humidity control, crops could now be cycled with pinpoint accuracy with maturity dates as prime objectives.

In the past several years, cycled lighting and black cloth have made many technological advancements for the horticultural industry especially in blooming crops. Controlled photoperiods have sophisticated many crops and is


Author: James C. Perry

PP: 95

The use of plastics has greatly increased during the past few years and, until something better comes along, I feel that plastics will be used for many years as coverings for preservation of heat and for climate control in the growing of plants.

Perry's Plants has benefited greatly by the use of plastics in our growing procedures. We are currently using polyethylene sheeting, 4 mil, for winter covers and protection, as well as the corrugated PVC (polyvinylchloride) for a permanent structure.

The polyethylene sheeting is used for covering, during the winter, our temporary structures, which are made of bent &frac;12" pipe, giving the shape of the quonset hut, with a curved dome top. We have taken a standard 21-foot length of galvanized pipe and with the use of a homemade jig, bent the pipe to conform to the shape that we desire. There is a three-foot straight leg on each end and the rest of the pipe between these three-foot legs is curved into a half-circle. The reason for the straight


Author: J.H. Klupenger

PP: 97

Our experience with propagation and growing under polyethylene and fiberglass gives us encouragement for the future. I would like to give a few pointers resulting from our experience in propagation and from the changes we have made over the past few years. At one time we would not propagate rhododendrons under any condition other than enclosed cases in the greenhouses. At a later date we decided we could do a better job of propagation in closed greenhouses but in open benches, although with no ventilation for fear of the cold air "chilling" the cuttings.

At the present time we are propagating in open benches but with air-conditioning fans (on thermostatic control) moving the air directly over the cuttings. We are having a greater percentage of rooting now than ever before.

At earlier dates, we were cautious as to the type of mist nozzle used so as not to get too much water on the cuttings. Now we are using Foggit nozzles; their output is three-gallons per hour. Formerly we used


Author: Ken Inose

PP: 98

PURPOSE: To propagate ivies, which is my principle crop during the fall, winter and early spring, with a structure that could be erected quickly when needed and then dismantled after the winter season. This type of house can easily be used during the summer with the addition of more coolers.

Two houses were in use from September, 1965, through March, 1966. The dimensions of each were as follows: 30' × 50' &times 15' in height at the highest point. The height is always one-half the width with this type house since it built in a half-circle. Each Airhouse was equipped with a dessert cooler on the south end-wall; a 100,000 BTU heater, thermostatically-controlled, was integrated with a squirrel-cage blower on the north end-wall. One or both of the blowers was in constant operation at all times to keep the houses up. During the heat of the day both blowers were in operation in order to move as much air as possible to keep the houses cool. With approximately 17,000 cubic feet of air in the house, the estimated


Author: A.H. Holland

PP: 100

Dr. Errol Rodda, Department of Agricultural Engineering, University of California, Davis, prepared a paper with the above title. It reports on two air-supported, water-anchored greenhouses which were used experimentally over chive plants. Construction details and estimates on costs of maintenance as well as production of some other crops are reported. It also briefly discusses air-supported row-covers.

From my experience I expect to see air-supported plastic greenhouses become quite common. There will be a diversity of designs for diverse uses. Some will be for long life and great durability against heat, cold and winds. Others will be used with a minimum of cost but with greater risk of destruction.

A few suggestions I might take are the following:

  1. A water anchor may have considerable value for certain conditions. I believe it can be most effective as a separate, one-foot diameter (more or less) tube and inserted in a larger fold-back tube made from the main greenhouse sheeting and running

Author: Tok Furuta

PP: 101

Dubbed the "Arkansas Razorback" by the editor of Jed's Jottings, this greenhouse was designed by Joseph W. Vestal and Sons, Inc. of Little Rock, Arkansas, a large producer of floricultural products. The clear span structure is simply constructed of prefabricated steel pipe arches and is covered with plastic.

The initial houses were 30 feet wide without posts or trusses. Later models are 40 feet wide. The steel arches are made from 1¼ inch steel tubing. For the 30-foot house, 21-foot lengths of pipe were used while 26-foot pipe was used for the 40-foot model. The pipes are joined at the top of the arch.

The ends of each arch are inserted into a length of 2-inch pipe, 2 feet of which is below ground and 1 foot above. The rows of anchor pipes are 4½ feet apart and adjacent houses overlay by this distance. Thus, the arches from adjoining houses intersect approximately 6½ feet above the ground. Channel iron, or "V" shaped wooden gutters are placed in this junction.

Along the length of the house the


Author: J. Peter Vermeulen

PP: 108

There can be no doubt that marketing, whether it be modern or ancient, does affect propagation. There is a line, sometimes broken or dotted and sometimes weaving but nevertheless a line, from the cash register to the propagator's list. Few ornamental plants really taste good. When one considers propagation in its pure sense however it would appear initially that propagation techniques in themselves would not be altered markedly by marketing or, for that matter, any other factors that are normally associated with growing as against propagation, per se.

In my lifetime practical propagation has advanced from a largely methodical and empirical concept to one of a more techno-scientific nature. Our nursery has always specialized in commercial propagation and the sale of liners and so we have tried to keep abreast of new methods and techniques and even to look into the future through research, our own and that of others. It seems to me that change in propagation has been brought about by


Author: Jack Matsuda

PP: 111

Propagation in the bedding plant industry has been basically the same for many year — sowing seeds, transplanting, and hoping for the weather to break at selling time. However, there has been many changes in modern marketing.

Discount houses and mass outlet retail centers have mushroomed around suburban living. To become more merchandising-oriented so that we may better serve our sales outlets.

Timing, distribution and packaging are some of the factors involved in marketing.

If you read your newspaper ads you will no doubt become aware that all retail outlets have anniversary sales, 1c sales, birthday sales and what have you, besides their regular holiday specials. To feature a certain plant for their ads, the grower must be informed well in advance since most stores place their copies ahead. We use our IBM system for computing and planning by categorizing our sales. No matter how much planning is involved, timing on certain crops is critical, especially when color is needed for appeal factor


Author: Daniel C. Veyna

PP: 113

As I see it the purpose of in-service training is to have a labor force that can operate a smooth and efficient, profit-making business. Before we go into how and what we as a business are doing about it, please ask yourselves these questions: Are you so important in your work that your business couldn't do without you? Would your business suffer a serious setback, or go broke without your services or the services of one of your key employees. If your answers are in the affirmative the chances are that your in-service training has room for improvement. I personally believe that no person from the lowest paid employee to the boss should be indispensable. With a good program of training, your work should be able to continue with or without you. Hopefully, of course, no one should be quite as good or do as well, otherwise we would be out of a job.

In our own business we have a lot of "chiefs" —so, at the managerial level, we shouldn't be running short for awhile. In fact, I have a younger brother


Author: O.A. Batcheller

PP: 115

"Nothing succeeds like success", and no one really learns to work at his top level until he has the responsibility and the rewards of his efforts.

It is difficult in a classroom or college situation to bring all of the factors of a commercial concern into bearing, for the time we have the students is only a part of their total commitment and they cannot live their entire time in the stress and strain of an economic situation.

We have found several different ways by which we can the student's scientific training, and we feel we have succeeded to a large degree.

First and most important is that the material we present in the courses is of a practical and applied nature, presented by instructors who have had wide and successful experience in the field.

Second, and perhaps equally important, is that field trips are arranged to places of business which are engaged in the type of work we are studying. In this manner we can show the student the extent of the enterprise. It is also an


Author: Edward F. Frolich

PP: 51

Many varieties of citrus will make satisfactory trees on their own roots (1). Nurserymen have grown Meyer lemon and Rangpur lime as rooted cuttings for many years. There are own-rooted trees of Navel and Valencia orange, Eureka and Lisbon lemon, Dancy tangerine, Bearss; lime, and Marsh grapefruit in California, some now over 30 years old. Contrary to the view held by many nurserymen, citrus trees grown from cuttings are not necessarily dwarf. Experience has shown that the sweet oranges, such as Washington Navel and Valencia, Marsh grapefruit, Dancy tangerine and Bearss lime, make trees of about the same size as standard budded trees of the same variety. Eureka Lemon in its early years is vigorous but tends to be short-lived. Lisbon lemon makes a vigorous tree but is very subject to fungus attack. Navel orange on its own roots also has exhibited a greater incidence of fungus trouble on the roots than has Valencia as a rooted cutting. We can say that citrus trees grown from cuttings reach

Author: Ed Gardner

PP: 117

Have you ever heard the expression, "Get out of my way. I can do it in less time and a lot cheaper than by standing here, watching you fumble around." Does this sound familiar to you? Maybe not, but a good many of us have heard a variation of this at one time or another in our lives, especially in the formative years in our work.

This somewhat exaggerates a very real problem that we have when training personnel for our nursery operation. Few nursery operations are organized and fully staffed in all departments so that a new employee merely has to imitate the man who is directly in charge of him. If your situation is typical of our operation you may find yourself with a new employee and a new problem. How do I get this man so that he can be left on his own and still give me a feeling of confidence — that of knowing the job is in good hands.

The diversified nursery that we have consists of field and container grown ornamentals, deciduous tree and vine growing, farming of cotton and beets, a complete


Author: William E. Snyder

PP: 123

The plant propagator is apt to take for granted many techniques of mechanization which were unknown to his predecessor sixty years ago. Continued mechanization in the propagation of plants is a necessity in today's competitive production of plants. Reduced labor costs, elimination of "human error" in judgment and accurate control of the environment of the cutting will more than pay for the costs of mechanization. Therefore, for a few moments, let us take a brief look at past and present methods of regulating the environment. I have chosen to compare today's equipment with those described in the 10th edition of L. H. Bailey's "THE NURSERY BOOK—A Complete Guide to the Multiplication of Plants", published in 1906 (1).

First, we shall compare the aspects of the environment—atmospheric and soil—considered of importance sixty years ago and today. Second, we shall take a brief look at some of the structures used to regulate these environmental factors, then and now. Finally, we shall examine


Author: Vincent Bailey

PP: 126

Technically this subject involves the idea of the use of machines in propagation; however, I am going to deviate or take some liberties with the, assigned subject. I am sure you will agree that the word propagation implies to the nurseryman and the research man not only the successful reproduction of a plant but further involves the successful establishing of this liner in a media for growing on to a useful size for distribution to the final consumer.

Webster says, "A machine is any contrivance to increase and regulate motive power, an engine, a light carriage, or vehicle." Some of the methods we, at the Bailey Nurseries, are now using do not truly involve machines, but they do involve implements which greatly improve the results and lower the labor costs. We are all interested in improving the quality of our liners, and this it as it should be. Most producers are finding that the buying public is very much interested in high quality and, what is more important, they are willing and


Author: Conrad Skimina

PP: 128

Mechanization is the use of devices, facilities or systems which will reduce labor requirements or create a more efficient operation. With the increase in costs, the nurseryman has to look for ways of cutting down expenses. One way is to develop a machine or a system that reduces expenses. Not all machines are made to save on labor directly, but their intrinsic purpose is to reduce labor costs whether directly or indirectly. For example, soil sterilization may be used directly to control plant diseases — however, this indirectly reduces labor because plants can be produced in a shorter time with less labor.

Designing a machine to do certain tasks in a nursery presents many problems normally not encountered in manufacturing. For example,

  1. We are dealing with disuniformity. Every plant is — different and, it is dynamic — always changing. At Monrovia we have over 1000 varieties of plants and each variety has its peculiarities. In contrast, in the manufacturing industry the basis of automation is

Author: O.A Batcheller

PP: 132

The advances made during the last 50 years in the production, handling, and germination of seed are well known to all of us. The quality and quantity of seed has become a constant and reliable factor. In the area of cutting propagation we have also made great strides by use of special rooting media, hormones, and mist. The one area where little has changed in the process of growing plants is that of transplanting and the handling of the seedling or cutting once it is rooted and is ready for transplanting. This is still the same process of carefully lifting the individual plant, carefully placing this in a container, and surrounding the new roots with potting soil. There has been little change, if any, regarding the soil, with the exception that it is now sterilized and perhaps more carefully prepared. It still is a loose, pliable mixture with just enough moisture to form a ball when held tightly in the hand, and yet of such a structure that it will break if this ball is dropped

Author: Steve Hillmer

PP: 133

The handling of rooted cuttings and seedlings is perhaps one of the most difficult aspects of the nursery industry to mechanize. The plants are small and tender; their roots are not well established, and are quite fragile. Machines are generally too rough in their operation to handle these small plants.

In the past it has always been not only more economical, but safer, to handle the transplanting of these small plants by hand. As has been pointed out, rising costs of labor, and a disappearing labor pool increasingly lead us to mechanize wherever possible. There have appeared numerous potting machines for transplanting larger plants into sizeable containers, and several semi-automatic machines to aid in transplanting small cuttings and seedlings. What Mr. Hoyles and I hope to accomplish is to develop a machine that will automatically handle and transplant these liners.

To achieve our purpose, the machine must not only be capable of handling and potting these plants, but must do it accurately and


Author: Mitchell Hoyles

PP: 136

The trend in all industries has been toward mechanization and the nursery industry is no exception. The mechanical operation of doing any job has proven itself to be an effective means of lowering the cost of producing a commodity. As long as man produces things, he will continue to create mechanical means to do it more efficiently.

Our senior project is concerned with the aspect of transplanting rooted cuttings and seedlings into plastic pots by machinery. This machine will automatically do all the necessary steps involved in potting. It will handle the plants, the soil and the pots.

An experienced worker can pot approximately 2500 cuttings a day. For any machine to be effective, it must do at least that. Hopefully, this machine will do many times more. In order for such a machine to operate certain theories must be examined and tested. One of these theories would be to eliminate bare-rooting the cuttings by compartmentalizing the flats. Another theory would be to treat the soil


Author: Bruce A. Briggs

PP: 139

Stimulated by the far-reaching talk1 by Dr. J. P. Nitsch of France entitled "Propagation in the Year 2000"; we were inspired to attempt a experiment in "air-rooting&quot. The principle was to induce rooting in a mist chamber, rather than in the usual media of sand, peat, etc. I have proceeded using basically an open case with the tops of the cuttings exposed. Another nurseryman in Olympia, John Eichelser of the Melrose Nursery, has conducted similar experiments using a closed case, but still confining the misting to the basal part of the cuttings.

The case was made similar to a grafting case with a 1 × 12 board used on each side. Flats made with wooden sides and 1½ mil polyethylene bottoms were set. on top of this case. The cuttings were inserted through the plastic, leaving the tops above and putting the basal part down into the closed chamber. Black polyethylene was found to induce better rooting than clear poly. A single layer was adequate for summer rooting, but a double layer


Author: W.A Humphrey, P.E Parvin

PP: 141

Higher daytime temperatures are used for foliage plant production which results in longer daytime periods when greenhouses are closed compared to many other greenhouse crops grown in southern California. A closed greenhouse during the light period offers an opportunity to utilize CO2 injections for growth stimulation. A study was conducted to determine if foliage plants would respond to elevated levels of CO2 in the atmosphere during the daylight period when the ventilators were closed. This was done in cooperation with Bob Weidner at Buena Park Greenhouses, Inc., Brea, California.

Two 18-foot-long greenhouse sections were used, one in each of two separate greenhouses. Each section was isolated by a polyethylene film curtain at each end of the 18-foot length and sheets of polyethylene film were tacked inside the remaining glass area except for the ventilator area. Temperature, light, irrigation and nutritional levels were maintained as nearly alike as possible in both units.

The study was


Author: W.A. Humphrey, T. Furuta

PP: 143

Adequate amounts of carbon dioxide (CO2) in the atmosphere during the daylight hours for plant growth is a, topic of much current discussion. Adequate CO2, levels should be important in the propagation of plants from leafy cuttings.

There is little information to indicate the levels of CO2 in various types of propagation units. Through the cooperation of Beckman Instruments, Inc. and Select Nurseries, Inc., Brea, California, measurements were made in several types of propagation units of the levels of CO2, during the light and dark periods. Measurements were made in cold-frame units, mist chambers and in a closed greenhouse maintained with a high humidity, commonly called a fog house. The cold frame units in which cuttings began to root and new leaves initiating showed marked deficiencies of CO2, during part of the light period. (Table 1) Only slight deficiencies during the light period occurred in the mist chamber and in the fog house. Where the normal level of CO2, in the atmosphere


Author: Paul W. Moore

PP: 54

The field propagation of citrus nursery trees is an old practice. Successful nursery techniques are well established and reasonably standardized throughout the citrus producing areas of the world. Until recent years, citrus nurserymen have shown but little interest in growing their trees in containers. Orchardists have been equally hesitant about planting container-grown stock. However, within the last decade, certain developments related to nursery tree certification, land and labor availability, automation, and transportation costs have generated a new interest in container-growing systems for citrus.

For many years, the University of California, Citrus Research Center, has been growing trees in containers for research purposes. Thousands of such trees have been planted in our orchards and have performed as well as field-grown nursery trees. The consequence of our favorable experiences was a decision to discontinue our field nurseries in favor of container growing. Some of


Author: Zophar P. Warner

PP: 167

Since the use of intermittent mist is common, it should not be necessary to review the various controls and ways in which it is used. However, since the use of fog is not so common, it would be well to explain again how it differs from intermittent mist.

Both systems are used to control the water content of the leaves. The mist system acts by keeping the leaf surface covered with water droplets, or at least covered at close intervals. The fogging machine acts by breaking the water into tiny sized particles which spread out and cover all areas of the cuttings; in effect, it is instant and constant humidity.

In dealing with mist and mist nozzels, the capacity is measured in square feet of surface, in the case of fog machines it is cubic feet of capacity.

Humidifiers, which fog machines actually are, have become fairly common in recent years both in homes and in industries. The measure of capacity of a humidifier must be measured by the amount of water the machine can break up in


Author: Brian Humphrey

PP: 170

Mr. Chairman, ladies and gentlemen, may I say what a great pleasure it is to be able to talk to you even thought I am very sorry I am not able to appear before you in person. Here at Hillier's now we have quite a happy band of Plant Propagators' Society members. With Pete Dummer, head propagator, and Asger Laursen in charge of mechanization on the nurseries. The next slide after this rather horrible apparition which must be on your screen at the moment is one of Asger on one of those special narrow row tractors and the following slide shows Pete Dummer at work in one of our rather old-fashioned English propagating houses. Next we see Pete at work on one of the older types of grafts, the Rhododendron saddle graft which was up to a few years ago very popular here. We find, however, that this graft shows very little advantage over the side-veneer graft recommended and described by Mr. Wells in his book on propagation. It is surprising how tradition dies hard for the side-veneer

Author: Stuart H. Nelson

PP: 174

Bottom heat is a practice of supplying additional heat to the medium and is not limited to the rooting of cuttings as we propagators might think. In fact, it possibly has more use in the forcing of growing plants than in the rooting of cuttings. I suppose that the first use of bottom heat can be traced back before the "Dark Ages" as with most of our horticultural practices, but I have not tried to do this. Rather, I will limit my remarks to the use of bottom heat—mostly electrical—as we know it today. It would seem that the acceptance of electricity, rather than manure, could be dated at around 1930 and in the early 1930's, there were a number of reports from different countries describing the installation and economics of such a procedure (1, 4, 7, 15). The economics of electricity over manure would seem to have been easily proved (5, 23) but I am not sure that I can say the same, without considerable reservation, for the beneficial effects on rooting.

By the way bottom heat is


Author: Harvey Gray

PP: 182

The concept of generating heat with electric power by the device known as Cellotherm was discovered by accident. It is said to have grown out of an attempt to formulate a ski wax. Somewhere along in the preparation of the ski coating, it was discovered that when an electric current travels across a film of colloidal silica and graphite, heat is generated.

To put this principle to practical use, the graphite-colloidal silica film is made up as a sandwich. The graphite-silica is the meat and the asbestos, two thin layers, is the bread. If the sandwich is to come in contact with moisture it must be made water tight. Laminated plastic films accomplish this. The electric power is introduced into the sheet by the way of two embedded copper electrodes along the edges of the sheet. In September, 1965, the manufacturers' field man contacted us regarding Cellotherm's possible application in hotbed heating. Out of this contact our trials developed with greenhouse propagation.

The tests


Author: Ray E. Halward

PP: 183

Through the years at these meetings, many and varied techniques have been explained by fellow propagators. Many of us returned home full of ideas how we were going to adapt these innovations to our own particular propagating facilities.

Let us briefly review some of the earlier techniques that inspired many of us to change our old ways for new. In 1953 The Phytotektor Method of Rooting Cuttings by Harvey Templeton explained the rooting of cuttings in soil using mist controlled by a humidostat and timer. He related at that time that the technique was an attempted union of the English sunframe and new mist humidification. An idea he obtained from an article lie had read on mist, by James Wells.

A Simple and Inexpensive Time Clock for Regulating Mist in Plant Propagation Procedures by Charles Hess and William Snyder was the title of a paper that aroused a great deal of interest in electrical and mechanical controls in mist propagation.

In contrast, to these techniques, Leslie Hancock


Author: James S. Wells

PP: 184

A casual glance at this title would seem to indicate that our Society has gone "way out" in choosing a subject which would have very little direct connection with Plant Propagation. But I hope to show you that this is not correct, because with the highly competitive market and ever-increasing labor costs of today, we have to consider each and every operation and try to determine the most efficient and least costly method of producing our crop. To determine these costs we inevitably must consider some form of cost accounting.

That I, of all people, should get involved in cost accounting is really rather ludicrous because if there is one thing I dislike, it is office work and figures. But, before giving you what I believe to be a very simple but very accurate solution to this whole question, I want to explain how I became involved.

When I first came to America in 1946, to manage the Koster Nursery at Bridgeton, New Jersey, they were growing Rhododendrons entirely by grafting. During that first


Author: Alfred J. Fordham

PP: 190

In 1954 the Arnold Arboretum received a plant of Kalmia latifolia rubra from the Weston Nurseries of Hopkinton, Massachusetts. It was one of six selected from many thousands grown there through the years and was thought to be a seedling from one of Charles O. Dexter's specimens. Together with his important Rhododendron accomplishments, Dexter also made efforts to assemble superior forms of mountain laurel at his estate in Sandwich Massachusetts.

In 1957 when Roger Coggeshall was at the Arnold Arboretum, he worked with this clone and by using 2,4,5-TP succeeded in rooting 21 of 35 cuttings. They were made on the 20th of September and potted on the following 12th of February. The slides which follow show cuttings taken from plants of that propagation and they therefore are in a clonal line. Six 3-foot plants were moved into the greenhouse in the summer of 1965 so that soft wood cuttings could be processed as described by Alan D. Cook in Volume 10 of the Plant Propagator.


Author: Thomas S. Pinney Jr, Gene W. Peotter

PP: 193

Our nursery has sold Birch to the nursery trade for the past 100 years. During this time we have had many complaints and unhappy customers because the stock was collected and had notoriously poor root systems with crooked stems. The situation finally became so disturbing, and the demand was so great, that we decided that we must meet this problem with positive thinking and somehow develop a program of mass producing Birch in the nursery. As a result, 6 years ago we embarked on a vigorous program to solve the problem of commercially growing Birch in our area. This was a team effort from the start. Everyone in our organization understood the value of developing such a program and added ideas and constructive criticism. We received many helpful hints from our yearly attendance at the Plant Propagators Society meetings and from our friends in the florist industry. There is nothing new or revolutionary in the techniques we employ in this program. Rather I believe, the success has come from the

Author: John Vermeulen

PP: 202

This topic was on the list of suggestions and as we had some limited experience in this field for 2 or 3 years I offered to tell you what little I know.

For some years we had given up the propagation of Rhododendron from cuttings as it interfered with other items to be propagated in October–November. But 4 years ago I was asked to trim some Rhododendron Mrs. C. S. Sargent in early July. There were a number of very nice cuttings on those plants so I could not just throw them away but took them home. It was a very hot day and we had no ice or anything to keep them fresh. We picked out about 100 cuttings, made them and put them in flats under outdoor mist. The result looked very poor after a few weeks so I lost interest in them but when in late October I came to clean out the frame I found about 50% rooted.

This helped me make up my mind to try again the following summer. We again made about 100 cuttings of Mrs. C. S. Sargent which, by the way, is one of the more difficult varieties. We gave it


Author: Booker T. Whatley, Stanley O. Thompson, Jack H. Jefferson

PP: 205

The pecan, Caryo illinoensis, is propagated commercially by budding or grafting on seedling rootstocks. There are three major disadvantages encountered when one grafts or buds varieties onto seedling rootstocks:
  1. Considerable time and expense are involved and often with only moderate success.
  2. Seedling rootstocks have a tap root with a few lateral fibrous roots. This characteristic has been associated with poor survival of transplanted trees.
  3. Each seedling rootstock has the potential of being genetically different.

The need for an improved method of propagation of pecan has, therefore, been recognized for some time.

There appears to be only three published reports in American Horticulture literature that deal with the propagation of pecans by cuttings. Stoutemeyer (5) rooted dormant Greenriver pecan cuttings by pre-callusing and treatment with indolebutyric acid (IBA) ; no report was given on whether the rooted cuttings were transplanted. Gossard (1) reported the rooting of pecan


Author: Gerald L. Hanes

PP: 63

Soil fumigation in California has developed very rapidly during the last few years. This recent rapid development has been mainly through the utilization of the very volatile fumigant, methyl bromide. Prior to this time control of weeds, Nematodes, and fungi by fumigation was accomplished with the slowly volatilizing chemicals.

There still are large acreages being treated with these less volatile fumigants. Some of the most common chemicals used are dichloropropane-dichloro-propene (D-D), carbon bisulphide, methyl isothiocyanate, chloropicrin, allyl alcohol, and dibromochloropropane (DBCP).

The individual fumigants have their own application techniques and soil requirements, and it is not possible to list a set of rules applicable to them all. Generally, however, they require the following: soil moisture in excess of 40% field capacity but less than 80%, field capacity. It is best that the soil be moistened and the moisture maintained ten days before application of the fumigant.


Author: Joseph Cesarini

PP: 210

I am very honored to appear here today. In view of the limited speaking time, I have elected to speak on a few specific varieties of the many dwarf conifers I have available. The varieties of conifers I shall discuss have been selected alphabetically.


The first genus is Abies. The Abies family is a very large genus of forest size trees which has given us relatively very few dwarf forms. We root and graft some of these dwarf forms. In our part of the country, grafting dwarf firs presents somewhat of a problem because of the selection of understock. The understock we prefer is Abies pectinata or Abies alba; however, we do not raise our own understock and these species are difficult to find as seedlings in the trade in this area.

Abies balsamea presents a problem because our winters are not cold enough and our summers are a little too warm.

Abies concolor is readily available but grows so vigorously that it does not do justice to the dwarf forms. To overcome this problem, we


Author: Richard A. Fenicchia

PP: 213

In 1869 the French missionary priest, Abbe David, discovered a remarkable tree while making botanical collections in the western Chinese province of Szechuan. In 1871 it was named Davidia involucrata for its discoverer. Nineteen years later the hairless-leaved variety which has proved to be usually hardier than the first hairy-leaved type, was found in the same province and another explorer sent seed to the French horticulturist, de Vilmorin, who raised one plant. The news of this rare discovery reached the Veitch Nursery in England, then at the height of its prominence. They sent E. H. Wilson on his first expedition to China (1899–1901) for the sole purpose of bringing this plant into cultivation. This was a successful venture since from the fruits sent back at this time the Veitch Nursery produced thirteen thousand seedlings. In 1903 and 1904, Wilson collected the pubescent-leaved type for Veitch who now were able to offer his diary of 1910 and the entry for May 30 and 31:

"On a


Author: Joerg Leiss

PP: 215

This paper is a continuation of a previous paper by Mr. C. deGroot and credit for these trials should go to Mr. Constant deGroot, a member of this Society from its early beginning. It was he who had the idea of using the various understock, while I worked with him. We started searching for better understocks after using Juniperus virginiana (Platte River source) entirely for years, but ran into a number of problems over the years. Heavy losses after grafting in the propagation bench from phomopsis blight were aggravated by uneven stands in the field, failure of seed to germinate and last but not least a poor root system and consequent transplanting losses, even after root pruning. To say the least, we came to a stage where you could say we were fed up. You have to consider that even a 20% loss of 60000 which we grafted at that time represents a large number of plants.

Our trials are concerned with the following Juniperus species and/or varieties, and I will briefly describe them


Author: Alfred M.S. Pridham

PP: 217

Weed — A weed is a plant out of place or an unwanted plant.

Some weeds carry plant diseases and insect pests while the mere presence of quackgrass in a plant ball is enough to restrict trade by quarantine in some states.

It is now 20 years since the selective action of "Carrot spray" was found to apply to the weeding of evergreen seed beds and that Dinitro killed seedling weed growth promptly on contact but that woody stems were merely defoliated.

Large scale soil fumigation was in use 20 years ago in production of Hawaiian Pineapples and mulch paper was laid by machine. Young cuttings or offsets of pineapples were set through the paper mulch and early growth proceeded with a minimum of interference from weeds. Those weeds that did grow were removed by hand usually by a weed patrol of two workmen much as "spot weeding" is done during the growing season in some nurseries today.

Today soil treatment is a professional job for custom applicators and much in demand in horticulture. Care and calibration of

HERBICIDES — Nursery Tool, Not Panacea

Author: William Flemer III

PP: 227

Not so many years ago, the program chairman of a nursery meeting who wanted to give a glimpse of the future would cast about for a speaker who knew anything about herbicides. After a long search, if he was lucky he would locate a college professor or extension specialist who had put out some test plots and could make some tentative recommendations, well hedged with the advice to go slowly. Now most nurseries use herbicides as a matter of routine, and each one has its favorites as well as some special combinations which particularly suit that soil and climate. Experiment stations have files full of data, dozens of different herbicides are manufactured on a large scale, and dozens more are discovered and introduced for test purposes each year.

Despite this great body of experimental work and resulting information, the universal herbicide has yet to be perfected. Furthermore under the multitude of weather combinations of temperature and rainfall, varying amounts of crop injury occur in


Author: J.H. Tinga

PP: 235

This is a broad subject touching many aspects of the plant growing business, but generally we can say we are concerned with the effect of low temperature on woody plants. Also, sun and wind have bad effects.

This effect is different for different years. I hear the old timers talk about the near famine winter of 1898 and the bad influenza and deep snow of 1917. Many here remember that all Baldwin apple trees froze in New York State in 1935. We are still recovering from the wind and ice of 1963.

The effect is different for different months. Most recent for me was May 6, 1966, when a 24 degree night took all the new growth from boxwood and Taxus. Tulip Tree and White Oak were defoliated in the forest. This damage was associated with the tender stage of growth of the plants. We call this a late spring frost. Then there was the early fall frost of October 7, 1965, with the same dramatic results. In addition, I remember the 60 mile wind and minus ten F. temperature of February 1, 1966.



Author: Richard T. Vanderbilt

PP: 238

The structure is a 14' span polyethylene covered quonset house. The cost is about twelve cents a square foot in place and covered. We use it for winter protection of container grown material and to replace cold frames.

This structure evolved into a quonset house quite accidentally. We had considered, and to some extent, used the type of structures long since made famous by Bill Cunningham. Bill's designs are excellent and their only drawback is cost; about 50 to 60 cents a square foot. This cost can be sizeable when you need houses in multiples of miles. We have four miles of the 14' houses up at present.

Up until three years ago we were using concrete reinforcing wire to support the polyethylene above our cans. It is a material that did do the job after a fashion. It is almost impossible to work around once put in place. Watering is very difficult. Pulling plants is impossible without tunneling in from the ends. Covering is a problem because of the many sharp edges that seem to


Author: Paul Bosley Sr

PP: 242

Container grown material constitutes a major portion of our nursery growing; and as a result, our methods of protecting plant material was originally built around our need to protect these particular plants.

We have been using polyethylene almost since the beginning of polyethylene, and many of our methods are a continuing evolution or refinement of what we have done previously. However, the basic principle of polyethylene has not changed. It is a flexible covering that will allow the passing of gases but will not allow the passing of moisture through itself. It took us a number, of years to realize some of the basic advantages of this method. For example, we know that many of the Evergreen Azaleas and Rhododendrons will lose their bloom buds when the, temperature drops to around to 10 below zero; and yet when temperatures dropped to 25 degrees below zero, Azaleas underneath polyethylene protection, did not have their bloom buds damaged in the slightest. We know that there is a


Author: Andrew N. Adams Jr

PP: 245

It became apparent to us back in 1955, if we were to continue in the Azalea business we would have to find some means of protecting our plants better in order to have saleable plants in the early spring with good foliage and buds.

Polyethylene plastic was just coming into the picture around this period so we constructed a small house (12'×96') by bending some old electrical conduit into a half circle and covering with some concrete mesh wire 6"×6", thus making a quonset type of house. We installed a small exhaust fan in one end and several louvers in the opposite end, plus a couple of propane gas heaters used for curing tobacco in the Southland. The idea was to keep the plants just above freezing, with plenty of air to prevent leaf drop. The following spring the results were so gratifying, plus the fact the Azaleas were gone in no time, that we decided to expand this idea.

We constructed 12 gutter-connected houses with a truss type of roof design of ½ pitch for quick snow removal. These houses are each


Author: Gil Nickle

PP: 247

The need for cold weather protection of container grown broadleaf ornamentals became apparent at our nursery after severe losses during the winters of 1960, 1961, 1962. We are located in northeastern Oklahoma, in the Ozark Mountains. The average low temperature is 5 to 10 degrees F. below zero, and most broadleaf evergreens grown in containers, such as holly, pyracantha, euonymus, and some shrubs, are subject to varying degrees of winter damage. We felt that polyethylene covered houses offered the most promising solution to providing the needed protection, but several criteria had to be considered:
  1. The houses had to be low in cost.
  2. They had to be able to hold snow loads of 6"–12".
  3. They had to withstand winds in excess of 60 MPH.
  4. They had to be easily erected and dismantled as we intended to put up the houses in the fall and take them down in the spring.
  5. They had to do an adequate job of protecting the plants.

The structures I am going to describe are now being used for their third


Author: O.A. Matkin

PP: 65

The term "soil mix" is rapidly becoming a misnomer. In recent years there have been millions of plants sold which never saw "soil" as such. In the past two decades we have seen a radical departure from the old "green thumb" approach to plant production. The beginning of a new philosophy probably had its start with the John Innes approach in England. With the publication by the University of California of Manual 23, titled "The UC System For Producing Healthy Container-Grown Plants", an overall philosophy was outlined which has become an accepted approach throughout the world. In any final analysis of events which have occurred and will occur, economics must be accepted as the dominating factor.

Since the number of potential soil mix preparations is infinite, we should look first at the underlying economic factors which must influence our choice of formulation.

  1. Cost of raw materials is an obvious consideration. Why pay $5 for something which can be obtained in equal quality for $2.50? The

Author: K. Darrell Holmes

PP: 251

I am sure that many of you, perhaps all of you, have had much experience in storing ROOTED CUTTINGS, UNROOTED CUTTINGS, SCIONS AND BUDWOOD and probably have just as good a method as we, but I will try to give you complete information on our methods.


We do not have occasion to store great quantities of rooted cuttings for any period of time, but we do store rooted cuttings of Crimson Pygmy Barberry and several varieties of Taxus. These are stuck as semi-hardwood cuttings in greenhouse propagation benches during September. We carry them in the benches until about the first of February, then dig and wrap 100 per bundle in moist sphagnum moss and two millimeter polyethylene. We tie the wrap with a rubber band. We do not put the polyethylene over the tops. In fact, the tops of the Barberry cuttings are above the polyethylene about one-half inch, and the Taxus cuttings may be from one-half inch to three inches above the poly., depending on the length of the


Author: Ralph Shugert

PP: 254

Dr. Tinga, President Vermeulen, Society members and honored guests:

It is a real pleasure to discuss with you this morning the most fascinating, perplexing, and at times incomprehensible, phase of plant reproduction … seedling propagation. Over the years we have heard excellent papers presented covering many aspects of seedling production, and it is my intent today to discuss a few techniques we use at Plumfield Nurseries in Fremont, Nebraska.

Our seedling operation is divided between seed beds and seed rows, and most of the remarks and slides will concern the former. The field which encompasses our seed beds is very level, and the soil texture is quite sandy. There are approximately thirty acres of seed beds in this field. Perhaps I should pay more attention to the soil pH, and to N., P., K., but I don't — except that based on previous soil tests, we are quite high in both Potash and Potassium. These results are compiled on a response based on field crops. Soil pH is rather


Author: John J. McGuire, David C. Sorensen

PP: 257

It has long been a practice to apply auxins in either a talc or an alcoholic base to the basal portion of cuttings to stimulate root initiation and growth. This has been effective, provided optimum levels of auxin were applied. If concentrations were too high, inhibition of root elongation occurred. If concentrations were too low, poor rooting resulted. There are a few reports of auxin application to the foliage of terminal portions of cuttings either before (4) or after removal from the plant (1) (3), but significantly improved rooting was not obtained.

Terminal applications could be advantageous if they improved rooting without injury to the plant, or if they could be applied as a spray to cuttings in the propagation bench. Theoretically, it is feasible to apply auxins to the terminals of cuttings. It has been established by Went and White (5), and more recently by Leopold and Guernsey (2), that when IBA was applied to the distal (terminal) end of a coleus cutting some auxin


Author: Albert Lowenfels

PP: 260

I planned to bring containers of Hormones that are sold commercially and say a few words about my experiences with them. But then I felt that few words on the whole subject of root promoting substances would be of interest.

Hormones for plant growth are comparatively new. Baileys Nursery Manual, 22nd addition—a wonderful book in many ways published in 1919 says nothing about hormones. Neither does the article signed by B.M. Watson in Baileys Encyclopedia mention Hormones. Laurie and an assistant Professor named Chadwick in Modern Nursery mention Potassium permanganate and Sucrose as rooting aids. Their book was published in 1931. Also slight attention is given to acetic acid, Manganese sulphate and Manganese dioxide.

Hottes in How to Grow Plants (1940) cites the work that Boyce Thompson Institute did in this field since 1924, mentioning Dr. Hitchcock and Zimmerman, who defined a hormone as a substance produced in one part of the body usually ductless glands and is then transferred to another


Author: Robert A. Fleming

PP: 263


Gibberellic acid has been tested in various experiments by many researchers with the purpose of determining its usefulness in the field of horticulture. Much has been discovered with respect to the effects on the above-ground parts of plants. Little information was available in 1957 on the direct effect on root promotion as in the case of cuttings or root growth as it is affected by treatments with gibberellic acid. For this reason the following study was carried out. It was conceivable, as in some ways gibberellic acid duplicated the response of plants to treatment with known auxins or plant hormones, that the material might also favorably affect root induction in plant cuttings. The effects of the known auxins were well established, toxicity levels were known, and the inhibiting effect on root growth was known. Little information was available at the time concerning this phase of research using gibberellic acid. From literature available it was evident that


Author: William E. Snyder

PP: 267

The propagator's search for chemicals to improve the rooting of stem cuttings has been directed primarily along two lines: first, chemicals which increase the rooting response itself; and second, chemicals which reduce the incidence of disease in the propagation bench.

With the discovery, in the mid-1930's, of the stimulating effect of indoleacetic acid and related compounds on rooting, it was hoped that successful rooting of all stem cuttings would be relatively easy. Such a naive idea, however, was soon expelled for, as was soon learned, the cuttings of many plants remained difficult to root even when treated with these chemicals.

There are numerous factors which contribute to a possibility of disease in the propagation bench. The use of soft, succulent plant tissue, the frequent presence of systemic diseases within the stock plant, the everpresent spores of fungi on the plant, in the air and the medium, the use of warm, humid conditions which are equally suitable for growth of


Author: Walter Peffer

PP: 272

During the past five years I have experimented with various methods and systems for growing Rhododendrons in the greenhouse with the aid of artificial light.

In October 1965 I purchased a newly developed 100 watt Westinghouse Viscount Mercury Vapor Light, no. 890D569G33, for experimental purposes. The Mercury Vapor Light, according to the electromagnetic spectrum consists of 20% ultra violet rays from bactericidal of 2,500 angstrom units through the erythemal and black light to 3,800 angstroms. These rays do not produce energy. The remaining 80% of light which is energized are the visible rays of 3800 to 5,800 angstroms. From this information it can be concluded that the mercury light contains more natural sunlight than any other artificial device. Infrared rays are present in small quantities.

Mercury Vapor Lights of higher intensity are also available, for example, Westinghouse no. 890D569G43 175 watt and no. 890D569G53 250 watt.

The plastic shield which is included with the lamp


Author: Harrison L. Flint

PP: 274

This program was started in 1962, shortly after I arrived at the University of Vermont. At that time it was apparent that one of Vermont's greatest horticultural needs was more accurate information on the hardiness of some of the better landscape plants. A testing program started at the University of Vermont ten years earlier had been carried on actively for three years, and then had lain dormant because of a personnel change.

For such a program to be of value to the majority of people in the state, it was necessary to test not only at the University of Vermont (in the Lake Champlain Valley) but in other parts of the state as well, since Vermont includes a range of average annual minimum temperatures from -10 to -15° F. in the southeastern corner, to -30 to -35°F. in the northeastern corner.

Fortunately, quite a number of species had been observed previously in Vermont, due to the efforts of local nurserymen and other people willing to experiment with new plants. Additional information


Author: Werner Rexer

PP: 278

Based on the principal of contraction and expansion of a special type of cordage, is the new misting and watering device, known as the Aqua-Vapor Control. The cordage in the wet stage, is approximately two percent shorter as compared when dry. (See Figure 1.) The control is equipped with a subminiature microswitch of one ounce release force rated at a maximum of 5 amperes and 250 volts. It has a life expectancy of over ten million on-off operations and is completely enclosed in a waterproof housing. A plunger connected to the cordage actuates the microswitch through a diaphragm. (See Figure 2.). The total travel required is five one thousandths of a inch. The contraction and expansion of the cordage is one eighth of an inch when changing from a wet to a dry condition. This allows for variation caused by heat or cold, and makes the unit self adjustable. The control is hooked up directly to the current of any type and to a solenoid valve, or a motor and pump. In the latter case, a relay is

Author: Leonard P. Stoltz

PP: 281

While working in Dr. Hess' lab I discovered that tobacco smoke blown into a piece of filter paper had a strong root initiating effect on mung beans which are used in the rooting bioassay developed by Hess (1). Later tobacco smoke extract which had been prepared by collecting the smoke in a cold trap from machines which automatically smoke the cigarettes was purchased and used. On the average 50 cigarettes yields 1 gram of tar.

In order to obtain an indication of the strength of the root initiation effect, one gram of TSE was dissolved in 10 ml of methyl alcohol. A serial dilution was prepared by reducing to one-half the amount of TSE for seven dilutions; the last dilution contained 1/128 as much as the first. Twenty lambda of each extract was spotted on filter paper and tested using Hess' mung bean rooting bioassay. In this case 1 on the ordinate represents 0.05 cigarette or 2 mgr. of TSE. Maximum activity of 68 roots per cutting was obtained with 1 mgr of TSE.

When TSE is chromatographed in


Author: Fred H. Petersen

PP: 70

STEAM-AIR OR AERATED-STEAM. These terms are used to describe a system or method of soil treatment in which treatment is obtained by exposing soil to a mixture of steam and air. The temperature of the resulting mixture is controlled below 212°F. by adjusting the ratio of steam to air according to established physics. While any treatment temperature between that of ambient air and 212°F. is possible, the temperature range between 140°F. and 160°F. appears most ideal.

PROGRESS. If measured by the number of successful installations now operating at high efficiency, and yielding daily benefits to nurserymen, such progress in my opinion can be summarized as:

     California — Disappointing to a point of concern.
     England — Encouraging as expected, since the concept is British.
     Australia — Enthusiastic, as evidenced by the manner in which Australian growers installed systems after a brief, but complete, introduction to the benefits aerated-steam offers.
     Eastern United States — Encouraging, as

Author: Booker T. Whatley, Stanley O. Thompson, George Williams Jr

PP: 287

Growing plants in nutrient solutions or aggregates moistened with nutrient solutions is by no means a recent development. In 1699 Woodward (6,9) grew plants in media such as spring rain, river, and distilled water to which he added garden soil. He observed a positive correlation between growth of plants and the amount of soil in the various media. These crude experiments represented the beginning of attempts by scientists to determine the nutrient requirements of plants. Very little additional study was reported in this field until Sachs, Knop, and Nobbe from 1859 to 1865 developed the general procedure for growing plants in aqueous culture solution. Knop later proposed a solution that has been widely used in the study of plant nutrition. Nutrient solutions have been proposed by Shive, Hoagland and many others (3,6,8). These studies provided experimental verification for the early theories that plants were made up of chemical elements secured from water, soil and air (5).



Author: Roy Nordine

PP: 291

The plant material described this afternoon from arboreta will be available at your request for propagation-seeds, cuttings, or whatever it happens to be. Nurseries, of course, are allowed to sell their plant material. (Editor's Note: The following plant material was presented.)

Cercis "Oklahoma" was discovered in Spring 1964 in the "Arbuckle Mountains" of Oklahoma. The flowers are a rich wine red over the entire bloom. The leaves are almost round, heavy textured with a glossy sheen that appear to be waxed. The leaves are closely spaced creating a neat appearance throughout the growing season. The trees start blooming at one year and bloom heavily at an early age. This tree seems to grow more compact and will probably not grow as large as the Cercis canadensis.

The "Oklahoma" Redbud is thought to be a natural hybrid between Cercis reniformis and Cercis canadensis having some characteristics of each. The best method of propagation is by


Author: Ralph Shugert

PP: 294

RALPH SHUGERT: I would like more information on the modification of temperature with the freezing and thawing of water under polyethylene structures. Isn't this heat from freezing lost too quickly to be of value? Are there any temperature data? What about 3–5 days of 10° F.? Would it help here?

DICK VANDERBILT: I think you can get about 10 days of useful heat between 5 and 0° F. This seems to be what it did. You can take the penalty out of the first deep freeze and if you continue to get low temperatures the rest of the winter you are just going to stay cool. But at the five days at near zero temperatures the water in the canal will be just like a frost in October. In the other houses the cans will be frozen up completely.

RALPH SHUGERT: If potted evergreens showing fall discoloration are placed in unheated greenhouses covered with opaque plastic — will the "greening up" process in spring be hastened or retarded compared to clear poly shaded 25% by white latex paint?

KNOX HENRY: Our experience


Author: James D. Kelley

PP: 302

Considerable emphasis has been placed upon studying the factors that influence the rooting of cuttings, the goal being to maintain an environment that will result in the greatest percentage of rooted cuttings in the least amount of time. Information that has been obtained has resulted in a manipulation of temperature with the addition of heat, moisture by misting, day length by shading or using additional light, application of growth regulators and others.

At the same time, little attention has been focused on factors influencing the stock plant from which the cutting is taken and how temperature, light intensity, nutrition, photo-period, hormones treatment, moisture, and other factors might influence rooting of the subsequent cuttings.

We often think of a cutting as the beginning of a new plant, but it is really the continuation of an existing plant and what the cutting will or will not do is to some degree influenced by the environment conditions under which it developed as the


Author: H.B. Tukey Jr, M.M. Meyer Jr

PP: 306

Spring is not the only time for nutrient applications to nursery plants, and it may not even be the best time. However, nursery plants in temperate regions grow rapidly during the spring and early summer. It is only natural to suppose that nutrient applications during this period would be most beneficial, and spring applications are common nursery practice.

However, many workers have shown that nutrients applied to woody plants during the spring and summer often produced no additional growth the year they were applied, but rather were absorbed and stored within the plants. The year following the nutrient applications, important growth differences were noted. Thus, the spring growth of woody plants is dependent to a large extent upon nutrient reserves accumulated in the plants prior to the spring flush (4), that is, during the dormant season. Thus, it becomes obvious that nutrients applied during the dormant season might be effective in promoting a greater amount of spring growth. However, the


Author: Richard W. Bosley

PP: 311


In recent years there have been rapid gains of knowledge in the fields of growing plants under stress. The coming of age of container growing has caused us to question many of our previous values and to investigate areas and industries that seem quite foreign to us, for the answers. Some of the areas in question we have discussed at this meeting, such as winter protection. Others, such as the medium requirements brought about by the short soil columns in cans, is causing quite a stir in the wood processing industries as they see a large potential market for their wood by-products. In California, redwood sawdust has gone from a material which the mills were glad to see you haul away to a rather high priced item of short supply today because Dr. O. A. Matkin, of Soil and Plant Laboratory, Inc. developed its use as a soil amendment. Another area which is still undergoing a revolution is that of plant nutrition and how to supply it. It has become increasingly obvious that


Author: F.K. Aljibury

PP: 75

In recent years there has been considerable interest in the use of the so-called "slow-release" or "controlled-release" fertilizers. The use of such products has offered several advantages:
  1. They can be applied at the rate required by the plants without causing excessive loss by leaching.
  2. The nature of the release allows for reasonable mistakes and over-application without burning the plants.
  3. Frequent application of fertilizers will not be required.

The characteristics of the slow-release and long-lasting fertilizers described in this paper are attributed to the following techniques:

  1. Membrane Coating. Fertilizers are coated by membranes of various sources and thickness. When the fertilizers are in contact with moist soils, water enters through the membrane and dissolves some of the fertilizers in the capsule. The dissolved fertilizers diffuse out of the membrane into the surrounding soil. The rate of release is manipulated by the thickness of the membrane. This technique may provide

Author: Toshio Murashige

PP: 80


Increasing use of the in vitro approach in botanical investigations and the expanding store of information prohibit a thorough coverage of the subject. This article is intended to simply acquaint the unfamiliar with some highlights of principles. Citations to original research should be viewed only as examples for illustration. More extensive coverage, including the historical development, can be obtained from several reviews and symposium publications now available (4,5,8,11,13,21,27,28,34,35,39,42,43).

The term "plant tissue culture" has been popularly used indiscriminately to denote cell, tissue and organ culture. It is desirable to distinguish between cell and tissue on one hand and organ on the other, since their behavior and requirements in culture are markedly different. The preferred term which encompasses each of these cultures is "in vitro culture" and it is therefore used in this article.

Fundamentals which apply to any in vitro culture shall be examined


Author: Wesley P. Hackett

PP: 88

Some very interesting and exciting experiments have been carried on in the past 15 years to show that shoots and roots can be caused to form on masses of undifferentiated tobacco callus tissue cultured under aseptic conditions (13). It has also been shown with cultures of carrot callus tissue that embryos which ultimately will become normal carrot plants can be obtained from single cells (2, 14). These are examples of organogenesis and embryogenesis from undifferentiated tissue (tissue not recognizable as normal plant organs such as leaves, stems, or roots). In both cases relatively large numbers of new plants can be produced in a relatively small space under controlled conditions.

It is interesting to speculate on possible potential uses of such tissue culture techniques in plant propagation. Several possibilities come to mind:

  1. The use of tissue culture as a means of rapid propagation of new cultivars, especially hybrids which require a complicated seed production system.