TO AVERT RUIN

New Zealand Times, Volume XLVI, Issue 10538, 15 March 1920, Page 6

TO AVERT RUIN

ORCHARDS AND SPRAYING SCIENCE WILL WAGE WAR ON APPLE BLIGHTS. Before bis ’departure from New Zealand Dr V J. Tillyard, the newly-ap-pointed biologist to the Cawthron In; stiiute, gave to a "Now Zealand Times reporter some interesting details on tno war science will wage on the apple pests now proving’ a serious msiiacc to tlio orchardisfo success. . "The particular phase of scieutiha* work 1 shall be chiefly engaged upon in the Cawthron Institute, said X>r lilLyard, ‘'will bo studying the problem ot apple culture and the control of apple blights, which .are very seriously alfectmg the orchards in the -Nelson dns trict. There seems to be no reason why, in th© course of a few years, these blights should not be cither overcome or materially reduced by the application of the latest scientific methods. It will have to be a campaign on th© lines of Lord Kitchener’s blockhouse system in tlie Boer war, shutting the blight out of on© district after another; and it will 1 require a considerable number oi scientific workers. “I have a double plan of campaign, be continued. “I am going to study in all parts of the world the natural euo. mica of the woolly aphis and other pests, and breed those under control conditions at the institute, find out the most suecessful, and sec* that they are distributed to the orchardists. Th© object of tins is to do away with the ever-increasing cost of spraying, which, is an unnatural method. The cost of spraying is so great that if it goes on the men will be mined. The second plan is to grow all known typos of resistant apple stocks, and to carry out Mendelian experiments with these (hybridising and then segregating the different types produced), with a view to evolving resistant types suitable for the Nelson climate, bearing good, saleable varieties of apples, not poor apples, as many resistant stocks do now. In the Nelson district they have got the Northern Spy stock, which is resistant to aphis; but it Is a weak stock, and grows small trees, which become prematurely aged. We have got to find a stock that is strong and will at the same time reMst the aphis. The Northern Spy, being weak, - is resistant only with the roots and stems; and wo want a strong slock that, will be resistant right through, th© tree.'*