LEAFLETS FOR GARDENERS AND FRUITGROWERS.

Otago Witness, Issue 2308, 26 May 1898, Page 8

LEAFLETS FOR GARDENERS AND FRUITGROWERS.

No. 24.— Peach Curl, Blister, Leaf Curl, or Frenchinq (Exoascus deformans). . ' By T. W._ Kirk, . F.L.S., etc., London, Government Biologist. This disease attacks various stone-fruits* but especially the peach. The peculiar curled or blistered, aunearance which' the

young leaves of peach trees frequently pre- J stock preparations, first take 3gal from the "sent in spring is caused by a microscopic I stock solution of sulphate of copper, \nd fungus which attacks their tissues. Ihe • add to 17gal of water in a barrel. Second, blisters sometimes extend across a leaf, ■ from the stock solution of milk of lime, after sometimes along it. The entire leaf may > thoroughly stirring, take 2gal, move or less, bs so puckered-up as to be unrecognisable, j and pour slowly into the sulphate of copper or only a portion may be attacked. The i solution placed in the barrel, all the time illustration, which is taken from a photo- stirring and carefully watching the colour ; graph, shows them in all stages. It was when a clear sky-blue colour shows, iminefrom a tree very badly affected. The foliage diately stop adding the milk of lime ; it is becomes leathery, the blisters assuming then -ready for use. The foregoing may be various colours, from the normal green to considered a 22gal formula. For a SOgal red, purple , or white, or combinations formula add additional Bgal of water ; or of these. The foliage generally falls off, for a 60gal formula, add 38gal of water, stirand another crop is Ihrovra out, thus the j ling thoroughly all the time.

tree is exhausted, and the yield of fruit greatly lessened and deteriorated, or in severe attacks completely lost, because it usually falls a few weeks after setting. The attacks are worse in damp draughty situations and in changeable weather. The disease lives through the winter on the buds and in the wood, thus scions and buds from a diseased tree will carry the disorder into localities where it was previously unknown. Preventives and Treatment. — Nursery stock is frequently very badly affected, therefore take care that the yoxing trees are obtained from a reliable firm. Be most particular to avoid scions or buds from any tree that has had the least trace of the disease within two years. Keep a sharp look-out, and directly the disease appears in a peachorchard give the tree the greatest, attention and care ; no trouble should be spared at this stage. "A stitch in time saves nine." All prunings and fallen leaves from diseased trees should be raked up and burned-, especially in nurseries. Bordeaux mixture, properly made and applied, will check the disease. Soon after the JeaA-es have fallen, pruue the Irca and treat leaves paid prunings as suggested «,bove ; then spray the tree with Bordeaux mixture, full strength (22gallon). Again, just before the buds burst, with a Aveaker solution (60-gallon), and just after the petals have fallen with the same strength. The DraECTioNS iron matiixg- Bordeaux Mixtuhe aub : — Bordeaux Mixture, an excellent Standard Formula, convenient for reducing co any Required Strength: Take sulphate of copper (perfectly pure), 61b ; fresh unslaked lime, 4tt> ; water, 22gal. Place the sulphate of copper in a piece of sacking or any light clctb. Suspend it by a string from the top of the barrel, a *ew inches below the surface of the water, to dissolve, using IBgal of Avater. Then slake in a wooden tub 41b of perfectly fresh lime in as small a quantity of Avater as possible, adding the water little by little, never enough to cover the lumps, until slaking has been com pleted, Avhen slowly make up to 4gal. When cool, thoroughly stir and strain sloAvly the milk of lime into the copper solution, stirring thoroughly Avhile mixing and for an additional minute or tAVo, when it is ready for use as a winter spray, and is called a 22*gal mixture. By adding the requisite quantity of water, at the same time observing to keep the mixture thoroughly stirred, it caa lie diluted to a 30, 50, or 60gal mixture f oe spring and summer use.It is important to observe the method of combining the ingredients ; also, that the copper should be pure, and that unslaked lime should be used, not air slaked. It is further important to note that in order to obtain the best re&ults the mixture should be applied Avithin eight hours from the time it is prepared, or at most 22 hours owing to a complex chemical change which takes place. N In the application of Bordeaux mixture a general line of treatment to be recommended is : During winter, or before the buds start in spring, spray all the fruit trees with che 22gal strength ; again, just as the petals drop, Avith the 60gal mixture. If the Bordeaux mixture is made and applied as above it adheres tenaciously to the wood and foliage ; there seems no need for the addition of treacle. Stock Solution, Bordeaux Mixture. Owing to ordinary Bordeaux mixture" requiring to be used at least within 24 hou^ from the time it is made, stock solutions are noAv prepared ready, for mixing of both milk of lime and sulphate of copper. This is found a great convenience for use in large orchards. These stock solutions are prepared as follows : — Firstly , by dissolving in a barrel 100fl> of sulphate of copper to 50gal of water by exact measurement, so that each gallon will hold in solution 21b of copper sulphate ; secondly, a stock solution of milK of lime is prepared by dissolving slowly in water 1001b of fresh stone lime, to be made up to 50gal, so that each r allon of the solution will contain 21b of lime. This j solution of milk of lime, if kept airtight, wil ■ remain' fto for u,se (or several days. After about the filth day it would be better to make fresh. Ia prerM"£ Bordeaux, ittiiidirl folil jM l