ORCHARD SPRAYS

Hawke's Bay Herald-Tribune, Volume 81, Issue 2, 25 September 1937, Page 17

ORCHARD SPRAYS

Types and Methods of Application — — j INF0RMATI0N ADDRESS Types of eprays and motliods of appjying tliem fornxed tlio subject of an informative talk by Dr. Cunningham, plant researcb oliicer, of Auckland, who addressed a gatkering of about G0 fruitgrowers in tlxo Oddfellows' Hall, Hastings, last evening. Dr. Cunningbam paid particular attcntion to tlio ncw certilication scliemo by wliicli tlio rosearch departnient tests manufactured eprays and rocoxnmouds thoso which it finds succcssful. Dr, Cunniugbain;s talk contained hlnts of a helpful nature and was vory practical in its scope. At tlie conclusion lie answered a uumber of questions. Mr j. H. Milne presidod ovor the meeting whicli was called by tbo Hawko's Bay Fruitgrowors' Association. After the Labour Govornment had come into powor it had recognised all the scientifle aetivitiee in the Dominion, said Dr. Cunningham, and new branches and bureaux had been established to earry put the different aspects 01 the ^vork, His department had tackled m.my problems during the past two years, among thepi the introduction 0? certification sprays, In evgry part of the Dominion the growors had their own particular spraying problems, he said. He outlined the types of sprays used and the three g'tages at which they were applied to the trees, beginning with the fonndation stage ivhere insect eggs had to be destroyed by a strong concentratiou. For fungus diseases lime sulphur and Bprdeaus mixture were generally congidered best. the latter being more pifectivo for the foundatlon stage, esccpt for combating mildeiv, , Tar washes, petroleum oil sprays, and lijne sulphur were used in later stages for epmbating insect pests, and of theso petroleum oils wero the inost generally used. The o'ils covered the insects with a thin fillh and asphyxiation resulted. Thie method also kiiled the eggs in. the same way, though special types of oijs having a higher viscosity and lOaving a tliicker film were preferable, slnco eggs breathed so slowly. The second series of sprays waa the blossom eprays — almost exclusively lime sulphur. The petal-fall spray of lead arsenato was particularly necessary in Eawke '& Bay, where tho codlin mo th waa a problem. This was the only insecticido applied during the whole of the blosBom period. The third series, summer sprays, wero applied to check insect pests and fungus diseases which still remained. At this stage it was important to ehoose the sprays used so as not to injure the tree or the following year'a crop. Combinations wero helpful in shortening the time taken for spraying operations, and Dr, Cunningham outlined numbers of eombinatiqns and their effects, stressing the dangers which could reeult from eombining sprays without suffieient knowledge of their aetions, •• We are now doing your choosing for you by the method of certif ying and listing those which we have tested and found satisfactory," said Dr. Cunningham. This system was entirely voluntary both so far as the department was coneerned and also on the part of the manufaeturers, who could submit their products for test if they desired. A comprehensive system of testing was used, giving an exact and rapid idea of (the effectiveness biologically of the sprays subjeeted to it. Combinations with eaeh product were also tried.