PEG OF OLD DRURY"

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

PEG OF OLD DRURY"

DRAMA. Anna Neagle—Sir Cedric Hardwicke Also Sydney Howard in "Hope of His Side” (Recommended by Censor for Adults.) Reserves at Bridges’—’Phone 4246. the patient and exact recording over a period of years to see how the trees on the different quince stocks grew and fruited, to mark the good and bad qualities of eacfy so that in future years it would be possible to say with some certainty how these varieties of pears behaved under our conditions when worked on this or that variety of quince stock. In the first ten years’ experiments it was possible to show that when the popular Angers quince and the common quince were used as stocks the trees behaved in a perfectly normal way, growing to medium size and producing ordinary crops. When, however, certain other quinces were used as stocks, something seemed to go wrong. In some cases the buds died soon after insertion, in others union took place and the trees grew, but remained stunted and unhealthy, often dying off several years after being planted out. This so-called incompatibility between stock and scion particularly noticeable in the case of certain scion varieties and of certain quince stocks. The trouble had often been noticed in commercial plantations of pears on mixed quince stocks, but it was not until the quince-stock material had been for the first time sorted out, and trial plots of the same variety planted, that it was possible to show conclusively by pointing to one row of dead or dying trees on one quince stock next door to a row of flourishing specimens on another, that this so-called "incompatibility” was entirely a question of root-stocks. In just the same way, when the stocks for plums and peaches came to be submitted to the same searching inquiries, it was found that on one of two of the best-known root-stocks, such as Brussels and common plum for plums, and on one of the St. Julien seedling stocks for peaches, exactly the same phenomenon occurred with certain scion varieties.

With plum stocks, too, it was possible to show quite big differences in size of tree and in time of coming into bearing as a result of stock effect, and this has made it possible to give positive recommendations for planting distances, and for garden as compared with orchard trees. In regard to cherry stocks, while no such striking instances of incompatibility between stock and scion have yet occurred as in the case of quince or plum, it seems that the Morello cherry will not. do well when worked on the Mahaleb stock. On the other hand, selected specimens of the wild Mazzard stock which have been raised in bulk from stools or layers have shown themselves to be far and away superior from the treeraiser’s point of view to mixed seedlings of the same age, giving almost three times the number of successful buds, and taking a year less to reach the required stage for budding. Practical methods have been worked out for raising desirable root-stocks of apples, pears, plums, and cherries by vegetative propation. Through the investigations of the physologist into the best times and condition for producing adventitious roots in the layer or stool, it has been shown how every nurseryman can raise his own root-

stocks vegetatively on a commercial scale, and the whole-hearted response of the tree raisers of this country has shown the value of this work. Ever since the war. East Mailing stocks have been distributed in everincreasing quantities to the nurserymen; this year 250,000 root-stocks were distributed in this way and even this did not meet all their requirements. In addition, the expert staff of the station is frequently called in to identify and rogue stocks. Numerous samples are sent us by post for the same purpose, and in many nursery catalogues reference is made to the various apple root-stocks by the number originally assigned to them when they were classified at East Mailing some twenty years ago. A fascinating sequel to the work on root-stocks described above has been the study of the growth of fruit tree roots in the soil. Whole trees have been excavated, trenches being dug to uncover the entire root systems so that these might be reconstructed to show their actual position in the soil at the time of the cxcavation. This work, carried out with the same variety of tree on different kinds of soil, has thrown a flood of new light on root growth, and while showing how little is really known about the subject, has at the same time suggested infinite possibilities for further research. It has led, for instance, to the installation at East Mailing of several elaborate underground observation posts where, with the aid of a microscope, minute investigations can be carried out into the times of growth and the methods of root-spread. Meanwhile, above ground, a series of uninterrupted experiments into the winter pruning of apple trees has been going on for twenty years, as a

result of which it has been shown that, the grower can by properly adjusting his methods to the varietal habits of his trees and to the purpose for which they were planted, keep his growing tree much more under control than in the old days when a rule of thumb method was rigidly applied. At a time like this, too, when growers are looking to their neglected orchards to see what can be done to make them pay their way, there is a good deal to be learnt from a more recent series of experiments at East Mailing upon the effect of different methods of renovation of established trees by pruning. Then again, in the manuring of fruit, the past twenty-one years have revealed much that is new and of great practical importance. Following on Dr. T. Wallace’s invaluable pioneer work on potash manuring it was possible to demonstrate at East Mailing the potash-deficient propensities of certain root-stocks still in common circulation. Again, from ‘

own experience, East Mailing was able to demonstrate the bad effects of the high nitrogen feeding tradition for apple trees, and by a sustained experiment over a period of years was able to show a big increase in yield and quality of fruit by the application of yearly dressings of sulphate of

potash to established apple trees. During recent years fruit growers in this country have turned their attention to the varying reports from abroad regarding the possibilities of still further controlling the behaviour of their trees by means of artificial thinning of the crop at a comparatively early stage of their growth. Experiments at East Mailing in the thinning of apples and plums have proved extremely encouraging, and by the simple method of keeping exact accounts of the final crop of fruit from thinned and unthinned trees respectively, it has been possible to show just how far the operations has proved a profitable one after all nec- ! essary expenses have been deducted. Even in the packing shed, where ' the fruits are graded and despatched ■ to market, the visitor to East Mailing will find that experiments with known material are still going on. Here modern packages are tried out and comparable samples are sent to wellknown markets in order that reliable figures may be obtained on which to build up an orderly system of marketing. Fruits of all kinds, true to name, and of known pedigree are sent off to research workers in other parts of the country for chemical analysis, for trials in canning, in jam-making and in different methods of storage. Last for convenience, although by no means least in importance, mention must be made of the war which pathologists are constantly waging against the numerous diseases and pests of fruit trees. From the earliest days it became more and more obvious that no satisfactory research could be carried out into the problems of the fruit-grower if at any moment the whole of the experimental results were liable to be cut clean across by the incidence of some fell disease which could not be controlled for lack of knowledge as to the cause and cure. This was made painfully clear in the early stages of the work on black currants, and

throughout the investigations on both small and tree fruits, the same story has been repeated. Thus it came about that first an entomologist and then a mycologist were added to the staff, and from this small beginning has been built up the present formidable programme of research dealing not only with the life-histories of the most important economic pests and diseases of fruit, but including also a comprehensive study of spray mixtures. Inevitably the fundamental idea of knowing the material has brought the pathologists into close and continuous liaison with the other members of the research team. This can hardly be better illustrated than in the case of the work on the dreaded scab or black spot fungus on apples and pears. Beginning with a straightforward trial of different spray mixtures at different strength on trees of known history, it was not long before it became apparent that there were other factors to be considered in the control of disease apart from the simple application of sprays. Thus, for instance, the inherited susceptibilities of certain scion varieties to "sulphur damage” and to "copper damage” soon made themselves felt, and it has since been found that external factors such as climatic conditions, pruning, manuring, cultivations, distance of planting and even choice of root-stock all played a part in making up the mys- | terious "environmental complex” of: the tree, and that any one ( of these factors might operate towards bring-; ing about a different result when I spraying for scab. Nevertheless, by following out the effect of such external factors in some detail, East Mailing has had the 1 satisfaction of evolving a scab spray | programme for its own conditions | which has worked efficiently for a I number of years. This programme was included in ; the spraying calendar which was sent | out last Christmas to all members and i which summerises in tabular form the application of the research findings to j the practical spraying of fruit trees, j Much more might be written if! space allowed about this important • aspect of the work, but here it must! suffice to say that just as at the be- [ ginning of the work at East Mailing, 1 the pomologist found he could make i no headway without calling in the aid i of the pathologist, so the pathologist ■ has made the equally important discovery that he must work hand in j glove with the pomologist if he would discover the whole truth about disease control of fruit trees.