A Few Remarks Concerning Research
Dr. Clement G. Bowers, Maine, N.Y.
Our more prominent growers of rhododendrons and azaleas and those most concerned with this Society live and work mostly in areas where natural conditions favor these plants. Of course, there are limitations of temperature, season and species in every spot. Yet little credit can be given to those who find it easy to raise, maintain and hybridize these plants in comparison to those who have to struggle for the very existence of any rhododendrons at all.
Despite the growth of our Society and the extent of the rhododendron cult, there still remain vast regions where the growing of rhododendrons is relatively difficult, although the ordinary climatic factors such as temperature and rainfall are seemingly suitable. This is particularly true in parts of the East and Midwest. For example, in and around such large urban centers as Syracuse, Buffalo and Chicago thousands of people would be growing hardy species and hybrids if that were easy and foolproof. These people see such plants elsewhere and are hungry for them, but their average experience has been rather tragic.
In some instances, the answers are known, or knowable, but many are unique. Obviously, this is no simple problem or one to be solved by the usual amateur approach or mere dependence upon pH or some rule of thumb. A great deal of excellent and competent research is being done on various aspects of rhododendron physiology, such as the work at Beltsville and the U.S. National Arboretum, and I shall not take time to go into this.
My main thesis is that more emphasis needs to be placed on this sort of thing, for it is time that we knew more about the vital phenomena associated with ericaceous plants.
Because rhododendrons and azaleas often grow more slowly, and also die more slowly than many common plants, results from experiments often exceed the time limits of one graduate student research project in a university. This kind of a project must be supported for a considerable succession of years and it may be expensive, too. Hence it is not a popular subject for attention by universities. Nor are lay persons equipped to pursue such inquiries. And commercial growers would find it unprofitable. It is a job for supported and endowed research institutions, and it is best if done in regions where specifically needed.
As one example of a deferred research subject, take the matter of mycorrhizae. Almost all ericaceous plants carry fungi on their roots as part of their normal equipment. The function of these fungi has been guessed at for many years and there is evidence to indicate that they are active partners in the life processes of their host plants. They go right inside the root cells and probably function in a symbiotic way. We call them endophytic mycorrhizae. We know that one ericaceous genus, Monotropa, possesses no chlorophyll and lives entirely without photosynthesis, getting its entire carbohydrate supply through the medium of a friendly fungus which inhabits its cells. A few well-directed experiments on rhododendrons might demonstrate how these organisms work, what they do for the host plants and perhaps offer some explanations and solutions of certain growth and survival problems.
Take again, the chemical picture. What do we know about the exact role of the element calcium? Apart from its effect on pH, is this element itself toxic and what are its relations with other elements, such as magnesium, iron, sodium, phosphorus, potassium and trace elements too numerous to mention? And how about those situations where rhododendrons grow on soil at pH 8? Some work has been done; more is needed. This requires a chemist.
Again, the many-sided matter of winter hardiness. Why will the flower buds of "iron-clad" rhododendrons be winter-killed in Ithaca at fifteen or twenty degrees below zero, when north in Saranac they survive and bloom after winter minimums of -40° F? Obviously, this is linked to other conditions and is not merely a question of Fahrenheit degrees alone. Is this, then, a matter of hardening-off in the autumn? Or is it due to some unexplained vagary, and how may it be circumvented? The people in upstate New York would like to know these answers.
In these examples I have mentioned only a few problems which, if ever solved, could conceivably help handicapped growers in marginal regions and vastly enlarge the boundaries of rhododendron culture when studied and understood. I could add innumerable other considerations such as day length, season, water relations, peat moss, and a handful of other factors if I cared to do so. Seldom, however, is one basic factor to blame for nonsuccess. More often the answer to a problem is found only in the interaction of many factors, any one of which, under certain conditions, could become a limitation. And certainly, along with these physiological factors, the matters of heredity and breeding are important, too. But for practical purposes genetics can help in only a limited way.
Only by moving the site of my activities out of the relatively favorable environment of Long Island and into an especially unfavorable site in central New York has the truth become manifest to me that there exists a large need for further research into the vital phenomena of ericaceous plants and beyond that which growers in favored regions ever have to deal with. Success, even in a limited scope, will benefit vast numbers of persons, not just the so-called experts, but those in the ranks of ordinary people who would like to enjoy a few of these wonderful plants but who presently find it difficult to do so.