Protecting orchards

Press, Volume CXI, Issue 32564, 25 March 1971, Page 10

Protecting orchards

Sir, —Every housewife who has tried to buy apricots and peaches for preserving this year knows what happens when frost wipes out the crops of Central Otago. I read in a magazine recently that a Russian inventor, famous in his own countiy for his automatic tea-picking machine, has now designed a protection for Russian citrus orchards from frost damage. The machine consists of a temperature gauge and a jet engine. When the temperature falls below a certain level, the jet sends an umbrella of heated air over a wide area, and keeps functioning until the temperature rises again. Could not the Department of Agriculture contact the Soviet Legation and endeavour to obtain one of these machines for experimental use? —Yours, etc., HOUSEWIFE. March 18, 1971.

(The horticultural superintendent of the Department of Agriculture (Mr F. L. Bailey) replies: “Wind machines have been used successfully for frost prevention in overseas pitrus orchards for many years. A wind machine was imported by Central Otago fruitgrowers a few years ago, but trials there proved unsuccessful. While the machine was not capable of emitting heat, it was found the warm layer of air over Otago orchards was always too high to reach. Most Central Otago orchardists are equipped to fight the normal run of

frosts. Unfortunately, spring frosts in 1970 were of such intensity that raising the temperature- to a level where damage could be avoided was an impossibility in many orchards. Frost prevention in New Zealand orchards has been, and currently is, the subject of research by many organisations. Improvements are being made continually, but of necessity any installation must be economic to operate. I thank your correspondent for her suggestion, which will be investigated.]