SPRAYING TIME

Hawke's Bay Tribune, Volume XXIII, Issue 211, 19 August 1933, Page 11

SPRAYING TIME

WORK IN THE ORCHARD PREVENTION OF LEAF CURL. ADVICE OF MR. N. J. ADAMSON. Suitable weather conditions have given orchardists in the district an opportunity to commence their spraying operations, and many orchardists now have this work well under weigh, red oil spraying being chiefly carried out. Referring to this branch of orchard activities, Mr. N. J. Adamson. Chief Orchard Instructor in Hawke’s Bay, in the course of an interview, stated that with stone fruits, particularly where red mite has been very troublesome in the past, a spraying of red oil, 1—25, should be applied immediately.

The most important spray for peaches and nectarines, according to Mr. Adamson, was that used for the prevention of leaf curl, and for this purpose he advised the use of Bordeaux mixture which was the most effective spray. One application at 5—4—50, if applied thoroughly, penetrating every nook and cranny, would give effective control with most varieties. The best time for using this spray was before any breaking of the wood buds occurred, and this was indicated by tho plumpening of the blossom buds when some of the most advanced would be showing a slight colour. At such a period the wood buds were not exposed. If, however, this spray was unduly delayed, there was danger of the most advanced wood buds on the terminal or strong laterals becoming attacked,

and in this way infection might bo set up. This spray should be applied immediately, said Mr. Adamson, if the full effects were to be obtained. With varieties that were notoriously bad for leaf curl Mr. Adamson stated that two applications of the spray would be necessary if complete control was to be obtained. It was an advantage to carry out the first application at leaf-fail in the autumn and in most instances this would have been done. Growers were realising the benefits of this application. “Where the autumn application has been omitted, however, there is still an opportunity of making two applications, the first immediately and the second —a 3—4 —50 application—at the pink stage. Thoroughness in tho application is absolutely essential. Any portions of twigs that are missed will invariably develop leaf curl.” Dealing with the use of hydrated lime in the making of Bordeaux mixture, Mr. Adamson said that it was necessary to regulate the quantity used according to the calcium hydroxide content of the lime. This could be determined by analysis, and was very necessary, as the commercial hydrated limes varied considerably. With samples which showed only 60 per cent, of calcium hydroxide should be used at 50 per cent, increase on the quantity stated in the formula.