ORCHARD PESTS

Press, Volume LXX, Issue 21245, 17 August 1934, Page 18

ORCHARD PESTS

SPRAYING FOR NEXT SEASON ADDRKSS TO KIM IT (JROWKRS Spraying for the coming season whs 1 cliscuKsctl at a meeting of the Canterbury Fruit Growers' Association Inst night, when an address on the subject was given by Mr B. G. Goodwin, orchards instructor for Canterbury. Before Mr Goodwin spoke those present outlined their methods of coping with the pests commonly found in their orchards. Mr F. VV. Sisson presided. After red mile, the leaf-roller caterpillar was the biggest pest. Mr Goodwin said. Last year one of the worst stages of the pest was at pink tip. By spraying it with arsenate of lead at the first signs he believed that it could be effectively controlled. After the caterpillar had gone in no spraying was of any use. He recommended a mixture of'tjib of arsenate of lead to 100 gallons for spraying at pink tip. If orchardists could control this pest they would be doing very valuable work. At green tip a solution of 8-fi--40 Bordeaux was needed for spraying. If a bad season of black spot was experienced and it was not cheeked immediately growers could go on spraying without any effect. Prevention was most necessary. Any sulphurs would not last longer than 14 days as fungicides. With a Bordeaux mixture an oil could be used in proportions of one to 20 or 25 with safety. All the oils marketed to-day were more easily mixed than they were a few 1 years ago, he remarked. Oil put on in a proportion of one to 25 at gre«sn tip would delay infection of red mite for months. Experience showed that codlin moth came out in the first or second week in November. Arsenate of lead could then be used, but growers should continue to use lime sulphur at 10-day intervals. If one went too long between sprays the danger of burning arose. Powdery mildew was another serious pest. For this lime sulphur should be used in proportions of one to 40 at green tip, and should be followed by a one to 70 mixture at pink tip. With arsenate of lead burning could occur, and some varieties of fruit were affected more than others. It had been said that with a mixture of arsenate of lead and lime sulphur burning had occurred, but that was not due to the lime sulphur but to the arsenate of lead. The thinning out of apples was imperative when trees wero infected with leaf-roller caterpillar, Mr Goodwin said. The trouble was most prevalent in Papanui, and one difficulty in combating it was that it was not confined to apples, but grew in flowers and macrocarpa hedges. White it was being controlled in orchards it might be flourishing in gardens. To control it another spraying in the middle of February and another in March was needed. Because of its prevalence in gardens, Mr Goodwin did not think that it would ever be eradicated. I