ORCHARD WORK.

Dominion, Volume 2, Issue 331, 19 October 1908, Page 5

ORCHARD WORK.

! THE SPRAYINC SEASON. The spraying season for fungus diseases began before the buds opened, but tho season for spraying against the codlin moth is now beginning. The time for spraying the pippin fruits against codlin moth is determined by the period at which the calyx i closes or is turned. downwards. Tho calyx I of a pear remains open longer than that of ! an apple, and in many pears tho calyx never ' closes. But in apples, soon after the petals s have fallen the little sepals of the calyx fold i over the eye and close it. It is necessary I to spray before this stago in order that the , poison may be doposited inside the eye as ■ well as on tho other parts of'the fruit. ' The codlin Moth. Very shortly the codlin moth will emerge 1 from its chrysalis and begin to oviposit. The eggs are laid on any part of the apple, but : often the young maggot wheh hatches from 1 the egg takes a tour round the apple or pear before it begins to bite. It usually ends up at the calyx, and there prepares to ! make a n entrance. If the fruit has been sprayed, the first few bites at the skin ' poison, the, youngster, and he dies. If the ' spray has not entered the calyx, and tho young maggot can push its way in between tho sepals and enter tho applo nnpoisoned, no amount of later spraying, of course can ' affect'him; Ho eats direct to tho middle of tho apple or pear for the seeds, and there ' develops to maturity. Bandaging does not Protect the Crop. ' ooikiwouldwado.-jOinutbsayKmC rdlu on on Thero are two chief modes of repression— spraying and bandaging. The bandaging does not protect tho current crop. It merely traps the maggots after they have done their mischief, and left the damaged apples, and thus it limits the infection of the following year:- Consistent bandaging done, however, has never been known to cause any reduction in tho percentage of loss from season to.'season. "In spite of the hundreds of maggots'trapped;. those that survive lay such .numbers of eggs that the v progeny aro always .;:numerou*s, VThe " 'bandages'. usually are small strips of / sacking folded onco and then banded round the stem of tho tree and lightly nailed together where the' ends meet. They are examined at least every ten days, the' captives which are found .nestling there are killed, and tho. bandages are replaced. It'is not yet time to bandage. Spraying is EfTeotlvo. Spraying, on tho contrary, is a preventive that protects the current crop. The Government experts report that in many cases it reduces the infection, from 100 per cent, to from 1 to 5 per cent. . Hitherto Paris green a of arsenic, has formed tho • poison basis of most of the sprays used. But now, after considerable trial, the authorities are adopting arsenate of lead; Tho Government Pomologist, Mr. W. A. Boucher, who some years ago conducted the spraying tests near Auckland, reports that last season many growers in tho North. Island used Swift's arsenate of lead with excellent results, and ho believes it will supersede Paris ■ green. Hero is the recipe for making the arsenate of lead preparation:— Mode of Preparation. Dissolve in a wooden vessel 12 ozs. of acetate of lead in 2 quarts of water, and in another wooden vessel dissolve 5 ozs. arsenate of soda in 3 pints of water. Pour tile contents of the two vessels into a tank containing 50 galfons of water, and the spraying mixture is made. It is found that'if pure materials are used this preparation is less liable to damage the foliage than Paris green, and it adheres longer to tho fruit. It can be obtained ready mado in paste form, with directions, as Swift's Arsenate of Lead, or in powder form as Disparenie. "Swift's Arsenate of Lead" (says the Government leaflet 10), "is a recognised standard brand which is largely used by apple-growers in California and elsewhero. Either of these preparations can now bo purchased at a sufficiently reasonable cost to allow of free use in commercial orchards. • Both can bo recommended as safe and effective." A Doublo Spray. Usually the big orchardists mix together tho insecticide and the fungicide spray mixtures, and apply both at one operation. This effects a great saving of labour, and is offectivo. The copper poison in tho Bordeaux mixture kills the germinating, fungus spores, and the arsenate of lead poisons tho newly-, hatched maggot of tho codlin moth. Both these preparations mix together well. How to Apply. Most orchardists aro well acquainted with the essential points in tho work of spraying. These aro chiefly a mistlike fineness which causes tho fluid to settlo softly upon the fruit like a mist, correctness as to quantity applied,. so that the fruit is covered completely but no drops form, and proper choice of periods for the application. For codlin moth trees should bo sprayed just after the potals have fallen, and at intervals of 15 or 17 days afterwards • till the crop is gathered. For the fungus pests there should bo winter sprayings of Bordeaux mixture, and a complete spraying just before the buds open in spring, and afterwards at intervals as may be necessary, but with a weaker solution. The summer and spring sprayings may be done in conjunction with those for codlin moth.