VEGETABLE PESTS.

Sun (Christchurch), Volume I, Issue 107, 11 June 1914, Page 11

VEGETABLE PESTS.

HINTS FOR SMALL GROWERS.

There are numbers of people in the country and suburban districts who grow vegetables in small quantities for home consumption. Now, many of such recognise that if they are to preserve their crops against the serious blights which attack them, it is necessary to. use the spray pump, but the majority would rather run the risk of having their patches destroyed than go to the trouble of making the Bordeaux Mixture and other simple washes, and applying them. This is chiefly owing to their not knowing what a really simple operation it is, and that to make the quantity required for a fair-sized garden, even where there are a few fruit trees, ; the only vessels required are" a kerosene tin and a'Mason ?« fruit jar. A simple formula for making Bordeaux mixture is as follows: — Bluestone (sulphate of copper) l|oz Unslaked lime .. ... .. .. 2oz Water ~ .» ~ .. .. .. lgal First dissolve the bluestone in a Mason jar with hot water (taking care not to use the water hot N enough to crack the jar). Slake the limejn the kerosene tin, and after adding the water, strain the mixture to take out the coarse particles and add the bluestone solution to it, stirring thoroughly. Don't reverse the process and dissolve the bluestone in the kerosene tin. For slacking the lime.only sprinkle it with a small quantity of water, adding more as may be necessary until the lumps of the burned lime have broken down to a fine white powder. As will be seen from the above, the process of making Bordeaux Mixture is a simple one, while the cost is little more than nominal. The mixture, as made above, is somewhat stronger in lime than usual, and is for use on potatoes. - TOMATOES ANT) POTATOES. The principal diseases " attacking potatoes are the Early and Irish Blights, both of which can be kept under control by spraying with the Bordeaux Mixture made as above.

There are three fungus diseases to which "tomatoes are liable —the Irish Blight,;, of ten called the potato blight (Phytophora infestans), Blaek Spot (Macrosporium tomato), and rust (Cladosporum fuloum). Of these, the last-mentioned is probably the least harmful in this country, but in some seasons it checks the growth of the plants considerably. Black. Spot, with which most growers, unfortunately, are familiar, is the source of considerable loss as the ripening season progresses, but regular spraying will do much towards keeping it in- check. For spraying tomatoes, add three pints of water to the formula given above to reduce the strength. Both potatoes and tomatoes should be* sprayed about once every ten days.

It must be borne in mind that the fungus which eauses the blight will attack any unsprayed portion of a potato or tomato leaf on even sprayed plants, so that it is necessary to do.the work thoroughly wish, to ensure success. Endeavour to Coat every portion of the plant, the under as well as the upper side of the leaves. When the tomato plants commence to set their fruit, the caterpillar will make its unwelcome appearance, and "soz of Swift's arsenate of lead the above compound will go a long way towards checking its ravages. It is perhaps rather late to mention that spraying should be commenced when the plants are eight to ten inehes high, and where tomatoes are always grown to spray regularly from the . start, season after season, and not to trust to a good season to pull you through.

CABBAGE AND CAULIFLOWERS. Leaf Spot and Leaf Rot, of frequent occurrence on these plants, may be eontrolled with the Bordeaux Mixture (same formula as for potatoes) if applied as soon the diseases are observed, they being easily recognisable—the names well describing their appearance. Burn all diseased leaves.

Club Root, as the name Implies, is a disease which attacks the roots, formicg large club-like swellings. As with most others, so with this infectious disease, preventive methods must be em,ployed. Destroy all infected roots"; plants for transplanting should be raised in clean pots; grow crops other than cruciferous plants for a year or two on infected land, care being taken to keep down all weeds belonging to the cabbage family. Heavy dressings of lime should be applied to the land. ■ The aphis and moth are very troublesome all over New Zealand. Frequent dustings with lime or spraying with hot water or (in the early stages) kerosene emulsion, are effective, but the first applications must be thorough. Hot water should be boiling when on the fire, as it will have cooled sufficiently by the time it reaches the plants, which will stand very hot -water without any injurious effects.

ONIONS. . Onion mildew is so common that it hardly needs description. here, but for the uninitiated it may be mentioned that it firßt appears oh the leaves in the form of yellow blotches, on which quickly develops a greyish mildew that rapidly affects the whole leaf, eventually destroying it. As a precaution, collect and burn all leaves of infected crops. A sure preventive of this disease is to spray the crop with Bordeaux Mixture (same formula aB for potatoes) as so6n as it appears, and repeat the application if necessary.

BEANS AND PEAS. Anthracnose in some form or another attacks the pods of peas, broad and French beans, and renders them quite unfit for consumption or market. If sprayed with Bordeaux Mixture (potato formula) as soon as the disease appears, and later, if necessary, it is easily controlled. The trouble may be recognised by the dark-coloured sunken spots caused thereby. All affected pods should be gathered and burnt, and only seed from healthy plants sown. CUCUMBERS, MAEROWS, PUMPKINS; AND TOMATOES. -

Leaf spot and mildew were very troublesome last season oh these plants. Bordeaux Mixture (tomato formula, viz., three pints water added to formula given at head of this article) will be found quite effective in controlling these diseases if applied sufficiently early— as soon as" the disease appears, and continuing at intervals, of ten days to a fortnight, the applica-: tiohs to be made, on a dull day or towards evening. ,

GENERAL. From the above, it will be noted that the one wash—Bordeaux Mixtures-is a panacea, if properly applied at' the right tithe, for most fungus diseases of vegetables and floriculturists will find the weaker formula also of inestimable benefit in the control of many of the fungi attacking their flowers.