SEASONAL SPRAYING

Hawke's Bay Herald-Tribune, Issue 195, 3 September 1937, Page 13

SEASONAL SPRAYING

Advice for Hawke's Bay Orchardists APPLES AND PEARS (By Mr. N. J. Adamson, Orchard Instruetor.) The new season's spraying programme is already under way and oii sprays, where considered necessary, have been applied in most instances. The necessity for an oil spray is determined by the presence of Ban Jose scale and the intensity of the deposit of re'd mlte eggs. For these two pests an oil sprat of not less than one part to tweuty of water is necessary. Several pear varieties are now too advanced for same applications of oil, but it is still reasonably safe to spray apple trees with oil for several days yet, but care should be taken not to apply oil sprays when the ,blos.som buds are too forward and ready to break. The prineipal spraying on apples and pears over the period up nntil blossommg is directed towards the control of fungus diseases — viz., black spot on appfes and pears and powdery mildew on apples. The general lines which should be adopted are as follow: — Black Spot C'ontrol, Should moist conditions continue, a more general use of Bordeaux mixture for the control of black spot might bo adopted with benefit. This applies particularly to pears, and to those apple varieties which are normally subject to black spot infection and are more resistant to powdery mildew, especially Dougherty, Delicious and Balldrat. Lime sulphur would be preferable on Sturmers, Dunns, Jonathan and Cox's OrangCj as lime sulphur is a good controliant of mildew. Bordeaux, if used on apples, should be applied at the "green-tip" period, but not later on account of its liability to cause russeting when applied later. At the "greehtip" stage, the bud scales have definitely lifted, the over wintering spores of black spot are exposed, and Bordeaux mixture applied at that period acts as a cleansing spray, and gives the maximum result. Strength of application (first) should be -as follows: — Bordeaux, green-tip" to ' ' tight cluster," 5 — 4 — 50, or lime sulphur, 1 — 30. A second application should be made at the early "pink" period at the following strengths: — All apple varieties, lime sulpkur, 1 — 75; pears, with the exception of Winter Gole, Josephines, and P. Barry, Bordeaux mixture, 3 — 4 — 50. The pear varieties nientioued may be sprayed in the second and subsequent applications as for apples. Where black spot has been troubleBome on apples previously a more intensive spraying programme might be adopted. Instead of only two fungicide sprays up to blossoming, three sprays might be arranged for, by bringing the second application a little forward and working in a third lime sulphur, 1 — 100, at full pink, or when a few of the more advanced buds will be in open blossom. This has the effect of narrowing the intervals between sprays at a critical time, which extends to soine time after petal fall. Spraying of Peaches. The spraying of peaches with Bordeaux mixture for leaf curl control would have been applied at least a week or ten days ago in most varieties. Bordeaux mixture at a strength of 3 — 4 — 50 may still be applied as a second application on varieties very susceptible to leaf curl and on peaches generally — where, through certain ciroumstances the spraying has been delayed. Cultivation. One cannot stress too much the importance of seeuring an early tilth and good cultivation to maintain moisture, in view of the possibility of a very heavy blossoming and fruit setting, following a year of enforced idleness, due to frost. Loss of moisture is soon reflected in weakened foliage, which is readfly damaged by Sprays and this is always more apparent in trees suffering fhe stress of heavy blossoming.