EAST MAILING RESEARCH STATION

Wanganui Chronicle, Volume 79, Issue 281, 27 November 1936, Page 9

EAST MAILING RESEARCH STATION

RESEARCH WORK ON FRUIT TREES In continuation of the paper written by Mr. N. B. Bagenal, M.A., on small fruits, the following paper on research work on fruit trees should prove interesting to fruit growers: In his opening remarks Mr. Bagen states that the process has already been described whereby the most important commercial varieties of soft fruits were subjected to minute scientific investigation as a result of which something like order has emerged from the chaos of twenty-one years ago. Turning now to the fruit trees, the first thing to remark is that seeking to "know” the fruit material was a much more complicated business than in the case of the soft-fruits, for the simple reason that whereas a currant or a gooseberry is a comparatively straightforward plant consisting of a single variety growing on its own roots, a tree fruit usually consists of a scion variety united by grafting with a root-stock variety. With apologies to a Poet Laureate, one may write that: — A Cox’s Orange Pippin tree A simple apple is to me To science something more. That "something more” being the rootstock on which the Cox’s Orange Pippin is grafted, and it was this nether half of the tree-fruit material which first occupied the attention of East Mailing, and which has continued to form the central subject of the investigations first with one tree fruit and then with another. In 1913 there was little or no precise knowledge as to which rootstocks were most suitable for different kinds of apple culture, apart from the rather vague recommendations to use "crab” stocks for standards and weak varieties and "paradise” stocks for dwarf trees. Space does not allow a fu’l description of the identification and subsequent classification of the seventeen different root-stock varieties which were sent to East Mailing under the name of "paradise.” Suffice it to state that by 1920 four sets of stocks were established, grouped according to their effect on the growth of the scion int > very dwarfing, semi-dwarfing, vigorous and very vigorous. Until that time a purchaser when buying a tree on "paradise” stock could ,never be very sure how that tree would turn out in point of view of size. The general recommendation for distance of planting of apple trees on "paradise” before the war was something in the nature of nine feet or ten feet square, and very many acres in Kent were actually planted at this distance. One of the most inchesting results of the root-stock trials at East Mailing has been to show that under normal growth conditions such a distance was too dose for even the most dwarfing group of paradise, and that when trees were worked on the more vigorous groups which were also included under the romantic term of paradise, distance of twenty iect tmd even thirty feet apart might be necessary.

As a result of this first attempt at the systematic arrangement of rootstocks into groups the fruit-grower found himself able to control to a greater extent than ever before one of the most important factors in the life of the apple tree. With the knowledge that a Cox’s Orange Pippin on No. IX is bound to make a smaller tree than one on any of the other three groups under similar conditions, the plantation or garden can be planned accordingly, and the most suitable distance for planting, while it must always be considered in conjunction with other growth factors, can at all events be calculated with very much greater accuracy than in the good old days when frees were being sold indiscriminately as "on paradise.” Another interesting result of these detailed apple root-stocks investigations has been the revelation of certain outstanding characters in connection with individual root-stock varieties, some good, others bad. For instance, the Jaune de Metz (No. IX), which in certain parts of Europe appears to have been used for dwarfing purposes for many years, had never been seriously tried out in this country until the early results of the East Mailing trials had given striking indications of its extraordinary powers of bringing even the slowestbearing variety into early cropping. Extended trials with many varieties have revealed further peculiarities of this stock, not the least remarkable being the effect that the stock appears to exert upon the size and the colour of the fruit. Or again, the case of Douchin Ameliore might be cited as an instance of a stock which, while being largely used for the production of paradise trees, has revealed itself after many years of trial as a real black sheep, giving trees which are all too ready to show leaf-scorch, and other "deficiency” symptoms when conditions are not exactly to their liking, and which under normal conditions produces in a coloured apple like Worcester Pearmain a singularly unpleasing shade of muddy red. All sorts of intriguing differences like those just described have continued and are still continuing to show themselves as the years go by.

Of particular interest to growers of Cox’s Orange Pippin Apple is the difference which in recent years has shown itself in the relative behaviour of Nos. I and II as root-stocks on this and some other varieties. Under East Mailing conditions it is now quite clear that Cox’s Orange Pippin makes a more -vigorous tree on No. II than on No. I, and this combined with the fact that in several other days No. I is proving itself a more satisfactory stock than No. 11. is likely to have a considerable effect upon Ute choice of root-stock for Cox’s Orange Pippin when required for bush trees of medium size.

Equally fascinating has been the story of the investigation of the quince stocks for pears. For centuries, pears have been grafted or budded on quince stocks when a relatively small-sized tree was required. Here, too, as in the case of the apple stocks, the first stop wa* to make a collection of quince varieties, to examine them botanically. leaf by leaf, and lenticel by lenticel, to identify them, classify and then raise each in bulk by stooling or layering of budding or grafting with one or more varieties of pear. Then came the planting out of this known material into trial plots and the patient known material into trial plots and