VEGETABLE GARDEN

Timaru Herald, Volume CXLV, Issue 21186, 5 November 1938, Page 15

VEGETABLE GARDEN

SPRAYING FRUIT TREES The spraying of fruit trees to destroy both insect and fungoid pests is an operation which has to be carried out at intervals from the time the leaf and flower buds develop until the fruit is almost fully developed, and though we may miss some of the pests, by regular attention their depredations are considerably reduced in a normal season. One of the most troublesome pests is the grub stageof the codlin moth (carpocaspae pomonella). This moth is a beautiful creature, three-quarters of an inch in the spread of its wings, the forewings being ashy brown, with dark streaks uniting into a broadlsh band towards the base. On the hinder portion of the forewings is a large reddish brown patch, spotted and surrounded by a golden mark. The moth emerges from the chrysalis about the time the apples and pears are in flower, and the female lays an egg in the eye of the fruit. This soon hatches out into a grub which at once sets about eating its way into the core at first feeding on the pulpy part and eventually on the pips. When fully fed it tunnels its way to the surface, and, if the fruits have not fallen to the ground it lowers'ltself by means of a silky thread. Grub-infested fruits often fall to the ground when the grub simply emerges and wanders about until it finds a tree or some other suitable place up which it can crawl and hide. It then spins a cocoon and becomes a chrysalis and in this form spends the winter. Numbers are destroyed by binding pieces of rough sack

or haybands round the trunks into which the grubs crawl and these can be removed and burned.

The usual treatment is to spray the trees with arsenate of lead, 21b. of the paste being dissolved in 50 gallons of water; The spraying has to be done immediately the petals fall, for in a short time the eye closes and then the poison cannot enter. When the grub starts to eat its way into the fruit it swallows some of the poison, and this does not agree with it. This operation has to be repeated when the fruits begin to swell.

Powdery mildew is one of the most troublesome diseases of the apple, and one which is frequently neglected. Trees Infected with this disease present a sickly appearance, they become partly defoliated, and carry only about a fourth the leafage of a normal tree. It attacks leaves, young shoots, blossom buds, and fruits, forming white or greyish cobwebby patches. Leaf infection occurs as soon as the leaves emerge from the resting buds, and it spreads progressively to subsequent leaves, buds and fruits.

To control this and other fungoid pests and also codlin moth, a combined spray is recommended, this consisting of lime sulphur one part to 100 of water, together with arsenate of lead 31b. dissolved in 100 gallons of water. This spray is applied as soon as the petals fall, and in 10 days the lime sulphur spray is repeated. A further spraying of the combined lime sulphur and arsenate lead spray is given every month until the fruits reach maturity. By applying a combined insect and fungoid spray time and labour is saved, and quite effective results are obtained.

APPLE SCAB The time for spraying against apple scab is now rapidly approaching, arid all recent experience goes to emphasise the Importance of early application of sprays. After years of research work on this, the commonest of apple diseases, there is still some doubt as to the source of the spores that give rise to the earliest infections. In America it is considered that such infections come from spores produced on last year's leaves lying on the ground. In England it has long been known that the fungus causing apple scab can overwinter in diseased pustules on the twigs of certain varieties, and that these twig pustules give rise to fresh infecting spores in early spring. The wood of other varieties, chief among which is Bramley's Seedling, is not susceptible to the fungus, however, and it has been thought that the earliest Infections on this variety must have come from last year’s leaves on the ground, as in America, Recent research work in Ireland has shown that, even on Bramley's Seedling, pustules of the apple scab fungus may overwinter almost unnoticed on bud-scales, or on the bark just below the’ base of the scales. Spores produced In these pustules are splashed about the trees in spring rains, and give rise to the very early infections. Recent observations in the Wisbech district also emphasise the very early occurrence of the first infections. Whether most of the early infections in England come from leaves on the ground, or from pustules on twigs and bud-scales, is still largely an open question. The practical significance of these observations is that the early sprays are the most important. Spraying should aim at preventing the establishment of infections on the very young foliage and fruit, for early infections, once established, rapidly produce new spores a thousandfold. For the best resWts two pre-blossom applications of sj)ray, one at the “greenflower” and one at the “pink-bud” stage, are necessary, even for Bramley’s Seedling and other non-wood-susceptible varieties.

LIQUID MANURE AND ITS APPLICATION Liquid. manure is so often recommended for pot plants, flowers, vegetables and fruits that a few notes on its preparation should be useful. It can be prepared from either cow, sheep, horse or poultry manure, or from soot, guano, or from either sulphate of ammonia or nitrate of soda. It is usually made by placing about a barrowload or less of the separate manures in a coarse sack and soaking this in separate barrels of water, or the more concentrated manures can be dissolved in water and applied direct. Fresh manure which has not been exposed to the weather should be soaked for preference, and this should be soaked for two or three days before any of the liquid is drawn off. It will be easily understood that the different manure will provide liquid of different strength, the poultry being the strongest, sheep next, cow next, and horse last. The first draw off will naturally be the strongest in fertilising properties, though it may not have the strongest smell or the darkest colour, and it should be used in a more dilute form. The colour of weak tea is often recommended, but colour is not a very good guide, and one part to four of clean water would do to commence with, the proportion of manure becoming greater as the strength decreases. If the liquid is drawn off regularly it will be necessary to renew the manure once a fortnight or three weeks, for it soon becomes exhausted, and too weak to be of any value. When applying to pot plants once a week during their growing period it is necessary to give a much weaker solution than that applied to plants in the open, and in every case both for pot plants and those in the open, it should be applied when the soil is moist, in dry weather after a watering with clean water. If applied to plants when dry it runs off through the drainage hole or into the subsoil before the roots have a chance to take it up. When chemical manures such as guano or sulphate of ammonia or nitrate of soda are used, about a tablespoonful of guano and a desertspoonful of either sulphate of ammonia or nitrate of soda may be dissolved in a gallon of water and applied direct. These manures are very valuable for stimulating vegetable and flower crops in the spring. They are clean and easy to apply, and are very useful where it is not convenient to have more or less smelly barrels about, though they are not quite such complete fertilisers as liquid made from animal manures. It only one barrel is available, and several kinds of manure are to be nad, it is quite possible to put some of each kind in the bag and to dilute accordingly.