HOME ORCHARD

Wairarapa Times-Age, 27 October 1939, Page 7

HOME ORCHARD

BLIGHTS BEST MEANS OF COMBAT. VARIOUS TYPES OF SPRAYS. (Continued.) (Bulletin published by the Department of Agriculture.) SCALE INSECTS. Scales," being sucking-insects, are found adhering to the bark of the tree or to the surface of the fruit and leaves and are mostly armoured —that is, covered by a natural shell-like shield. Mussel Scale. —This is a scale which attacks the apple, pear, and plum, and treatment gives considerable trouble where neglected to orchardists throughout the Dominion. If its presence is not detected and speedy and effective steps taken for its control, it spreads very rapidly ,a large number of eggs being produced by the female insect during the season. Maire Scale.—A native scale attacking deciduous and citrus fruit-trees, ornamental trees, and shrubs generally. Infection from this pest spreads very rapidly. The scale is somewhat round, of a dirty-greyish colour, and usually about the size of a large pin-head. San Jose Scale. —A troublesome insect pest attacking both stone and pip fruits, and one which may be considered to cause considerable damage in the orchard if not detected and effectively controlled. This scale, as compared in size with those already mentioned, is miniature,-is-of a greyish-white colour, and circular. Upon close examination it may be found that the immediate centre is of a yellowish colour, and in this respect it is easily distinguishable from the other scale insects mentioned herein. . Treatment. —The above-mentioned scales on deciduous fruit-trees are easily controlled by spraying with winteroil emulsion, 3 pints to 4 gallons of water, during the dormant season, preferably in July. However, if this spray has been omitted the young scales may be killed in the early summer, while they are on the move and before their shell forms and hardens, with summeroil J pint to 4 gallons of water, or nicotine sulphate (40 per cent standard) four-fifths of a fluid ounce (five teaspoonsfuls to 4 gallons water), first dissolving 2 oz common soap in the water. WOOLLY APHIS (American Blight). This is an insect pest too well known to need much description. It attacks many varieties of apples, and is most destructive. Its appearance is easily noticeable —a white woolly substance forming on the parts of the tree attacked. Infestation generally commences on the young wood or at the base of a leaf-stalk —the insect penetrating the wood tissues and sucking the plantjuices therefrom, causing the formation of warty growths on the parts affected. The insect increases rapidly, and, being protected naturally by the woolly substance and also by the growths and crevices caused by its attack, it is very' necessary in combating this pest by spraying that the compound used should be applied with considerable force in order that the insect may be well reached. Spraying is recommended as follows: During the dormant season, with win-ter-oil at a strength of 3 pints in 4 gallons of water; • and during summer months, with summer-oil J pint, to 4 gallons of water; or with nicotine sulphate (40 per cent standard) fourfifths of a fluid ounc.e (five teaspoonfuls to 4 gallons of water) to which is added loz of arsenate of lead (powder ed form). Soap should not be used in this combination. RED MITE. This pest, like the scales, is a suck-ing-insect living on the plant-juices of the leaves during the summer, and harbouring during the winter months in crevices in the bark or under forks ol the branches, etc, on apple and stone fruit trees. The insect itself is very small, brick-red in colour, and increases very rapidly. When neglected the affected leaves are distinguishable at a considerable distance by their sickly appearance, and eventually drop off. On apple-trees the treatment during the winter is similar to that advocated for woolly aphis —namely, spraying with winter-oil emulsion at a strength of 3 pints in 4 gallons of water. For stone-fruits use 2 pints of oil in 4 gallons of water. For summer treatment spray with summer-oil A pint to 4 gallons of water, or with lime-sulphur I—lBo1 —180 (equivalent to 4 fluid ounces to 4 gallons of water) several times at short intervals. It is'advisable to allow an interval ol at least three weeks to elapse between the applications- of sulphurs and of summer-oils in order to avoid injury tc the leaves. FUNGUS BLIGHTS. Fungus blights include black-spot on apples and pears, powdery mildew.on apples, and leaf-curl on peaches and nectarines. Black-spot (apples).—This fungus winters on the fallen leaves, and when conditions are suitable in early spring spores develop. These latter settle on the leaflets at the base of the cluster ol buds (known as blossom-buds) where the spores germinate and in due course attack the fruits. The spraying is directed to prevent their germination. APPLES. The following spray treatment for black-spot and powdery mildew control on apples is recommended:— (a) For Cox’s Orange Pippin. Sturmer Pippin, and other tender-skinned varieties —' (1) Green-tip: Lime-sulphur 1 pint ■ *to 4 gallons water. (2) Tight cluster of blossom buds (pre-pink stage): Lime-sulphui' 8 fluid ounces to 4 gallons of water. i 3) Pink: Lime-sulphur 4 fluid ounces plus colloidal sulphur loz (weight) to 4 gallons water. (4) Petal-fall (when about 75 per cent of petals have fallen): Lime-

sulphur 4 fluid ounces plus colloidal sulphur loz (weight) to 4 gallons water. (5) Remainder ,of summer: Repeat No 4 application at about eight-e'en-day intervals, according to weather conditions. (b) For other varieties it is recommended that Bordeaux mixture (5 —4 — 50) be applied at “green-tip” stage. To make this, use bluestone 6Joz, burnt lime, unslaked, sJoz, and water 4 gallons. Subsequent treatment should be carried out during the season on the lines outlined above. Black-spot (pears).—The attack of this fungus is similar to that of blackspot on apples. PEARS. The following spray treatment is recommended for control of black-spot:— (a) For Winter Cole, Josephine, and other tender varieties of pears — (1) Green-tip: Bordeaux mixture (5 —4->-50) lime. (2) Tight cluster of blossom buds: Lime-sulphur 8 fluid ounces to 4 gallons water. (3) Pink: Lime-sulphur 8 fluid ounces to 4 gallons water. (4) Petal-fall (when about 75 per cent of petals have.fallen): Limesulphur 4 fluid ounces to 4 gallons water. (5) Calyx (within ten to fourteen days petal-fall): Lime-sulphur 4 fluid ounces to 4 gallons water. (6) Remainder of summer: Repeat application No 5 at about eight-een-day intervals, according to weather conditions. (b) Other varieties of pears — (1) Green-tip: Bordeaux Mixture (5 —4 —50). To make, use bluestone 6Joz, burnt lime (unslaked) sJoz, ond water 4 gallons. (.2) Tight cluster of blossom buds (pre-pink stage): Bordeaux mixture (3 —4—50). To make, use bluestone 4oz, burnt lime (unslaked) soz, and water 4 gallons. (3) Pink. Bordeaux mixture <3—4 — 50). ,(4) Petal-fall: Bordeaux mixture (2 — 3 —50). To make, use bluestone 2Joz, burnt lime (unslaked) 4oz. and water 4 gallons. (5) Calyx (within ton to fourteen days of petal-fall): Bordeaux mixture (2 —3 —50). (6) Remainder of summer: Bordeaux mixture —3 —so). To make, use bluestone 2oz, burnt lime (unslaked) 4oz, and water 4 gallons. Leaf-curl (peaches and nectarines). —The fungus causing this disease commences to become active at the “greentip” stage of leaf-bud development ii* early spring, and is most troublesome during cold, wet seasons. It is readily held in check by spraying the trees in spring when the buds are swelling. Bordeaux at the following strength is advised: Bluestone, 6Joz; burnt lime. 5. l ,oz; water, 4 gallons, mixed as directed. An alternative treatment for leafcurl is as follows: Winter formula— Lime-sulphur. 2 pints; water, 4 gallons. PREPARATION OF BORDEAUX MIXTURE. The following directions apply to the quantities of bluestone and lime already given:— Dissolve the bluestone in 2 gallons of water; slake the lime slowly in another vessel, and make up to 2 gallons; then pour both solutions simultaneously into a third vessel. In using the mixture during the dormant season it should show a slight acid reaction —that is, when tested with litmus paper. Bluestone is readily soluble when placed in a piece of sacking and allowed to touch the surface of the water or suspended an inch or so below it. or by using hot water. The efficiency of bordeaux mixture depends upon the intimate blending of the two solutions obtained by pouring both of them simultaneously into a third vessel. It is imperative that the chemicals used be pure and the lime fresh. The best results are obtained when the application is made as soon as possible after blending the two solutions. If allowed to stand for more than eight hours the fungicidal properties of the mixture largely, depreciate.