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FRIJIT RESEARCH. Advisory Committee.—Sir Theodore Rigg (Chairman), Dr. G. H. Cunningham, Messrs. W. Benzies, T. C. Brash, F. R. Callaghan, A. H. Cockayne, J. Corder, W. K. Dallas, A. Osborne, R. Paynter, F. S. Pope, A. M. Robertson, 11. E. Stephens, L. W. Tiller (Secretary). INTRODUCTION. The principal changes in the research programme are the two extensions forecast in the 1940 annual report. One is the commencement of an extensive series of experiments on the non-refrigerated storage of fruit, and the other is the virtual completion of an experimental gas-store containing two chambers each of 500 bushel capacity. These are described in the section of the present report devoted to " Fruit Cold Storage Research." The Plant Diseases Division of the Plant Research Bureau has replaced the Huapai orchard by a more extensive property at Oratia, and details of this are given in the report of the Plant Research Bureau. Fruit research remains a co-ordinated series of investigations carried out by the Plant Diseases Division, the Appleby Research Orchard, the Dominion Laboratory, the Horticulture Division of the Department of Agriculture, and the Cawthron Institute. APPLES. Fertilizes Experiments. Research Orchard.—Tn the winter of 1939 the trees were heavily pruned, to remove crowded wood, and make them more accessible for field operations. In consequence, the yields for the 1940 season have been somewhat lower than usual. With few exceptions, phosphorus (P) is applied as superphosphate at 4 lb. per tree per annum, nitrogen (N) as ammonium sulphate at 2 lb., and potassium (K) as potassium sulphate at 1 lb. Cox's Orange : N has continued to give significantly higher yields of fruit than the untreated controls, and this year the " complete " PNK treatment has given a highly significant increase over N. No differences have yet been observed between trees treated with ammonium sulphate and trees treated with dried blood. Dunn's Favourite : This year the crop increases due to N and PNK have reached the level of statistical significance, with N better than the untreated controls and PNK better than N. Delicious : PNK trees have consistently carried heavier crops than the untreated controls, whereas the yields from N trees have been relatively very variable. Jonathan : The yield from PK trees is only two-thirds that from trees receiving 2 lb. ammonium sulphate additional to PK, and no more than half that from trees receiving 4 lb. ammonium sulphate additional to PK. The heavy pruning resulted in a reduced crop of large-sized fruit of rather low overlying colour, and consequently the inverse relationship hitherto observed between high overlying colour and high N has been very much reduced. Early spring, late spring, and autumn applications of ammonium sulphate are still indistinguishable in the effect produced on the tree. Higher yield and improved colour following two heavy dressings of 12 lb. potassium sulphate per tree, additional to P and N, are still clearly marked in this year's crop, which is the fifth following return to a normal dressing of 1 lb. per tree. Sturmer : N has continued to give a significant yield increase over untreated controls, and PN likewise over N. The increase given by PNK over PN has still not quite reached the level of mathematical significance. Cawthron Institute. —The long-term experiments on Jonathan at Upper Moutero have continued to show the necessity for PNK treatments. All treatments from which one of these three constituents has been omitted have given markedly inferior results. An interesting feature is the rapid decline, during the past three years, of trees receiving no potash ; growth and foliage development have suffered severely and fruit has been poor in colour, size, and quality. Trees receiving NK without P are now inferior in growth, foliage development, and fruit yield to PNK trees. Trees getting N alone are now little better than the untreated controls. With P and K requirements supplied, 2 lb. dried blood as an annual dressing is now very much superior to 1 lb. Rootstock Trials. The Plant Diseases Division is finding that the more vigorous of the East Mailing stocks are maintaining their lead in growth over Northern Spy. In consequence of the information secured in the trials, stocks of M. XII and M. XVI have been selected for planting in the new orchard area at Oratia. Varietal Investigations. The Plant Diseases Division has grown strains of Delicious and Cox's Orange on the dwarf M. IX stock. Classification "of the Delicious has shown at least fifteen colour-types, which can be broadly grouped into four classes. Differences in flavour, keeping-quality, and susceptibility to russet have also been noted. In studies of the susceptibility of these strains to mouldy-core it has been found that none possesses a sinus completely closed by living tissue ; but with certain strains the passage in a high percentage of the fruits is scarcely visible to the naked eye. The constancy of the passage diameter in each strain is being determined, and the effect of diameter on incidence of mouldy-core is being studied.

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