Orchard Pests.

Levin Daily Chronicle, 15 August 1918, Page 3

Orchard Pests.

SPRAYING OF FRUIT TREES (Issued by the N.Z. Agricultural Department. The orchardist of to-day has to contend with many diseases in order to grow fi-uit successfully. In many cases the grower lias no knowledge of the proper spray to apply for the particular disease he is trying to eradicate. There are a number of men in tlie various districts who make a business of spraying trees ; among these men are a few who appear to have a very rudimentary knowledge of disease control, so that gi'owers (particularly those possessing small orchards) should be careful in whom they employ for this important work. Those who hold a certificate for spraying and pinningl issued by the Horticulture Division can be relied on. As a guide to disease control we will divide the diseases affecting fruit trees into three groups: Chewing insects, sucking insects, and fungi. _ As chewing insects attack the foliage or fruit it. is necessary to cover the surface of the foliage and fruit with a coinpound poiso- , nous to insects; for this purpose use Arsenate of Lead at a strength of 31bs paste, or 21bs powder, to 100 gallons of water (2ozs. to 4 gallons). Although tliis poison is harmless at this strength, to persons and animals, it is death to the following chewing insects: Codlin moth, leaf-roller caterpiller, bronze beetle and pear slug. For codlin moth apply the spray first as soon as most of the petals of the flowers have fallen, following with a further application every 21 days throughout the season.

Sucking insects obtain their food penetrating the tissues with their rostrums .(beaks) so thai* poison applied on the surface of the plant would be of little avail in checking them. For control of these pests it is necessary to use a spray that will kil by asphyxiation, or by contact. Red oil is, therefore), tlie best spray for the following sucking insects: Woolly aphis, green .aphis, scale, red mite, and mealy bug. Apply in the dormant season, on apples and pears, using red oil 1—12; on stone fruits, I—ls.

As an early sumtaier control for woolly aphis use a soap emulsion of Black Leaf 40, I—Boo, adding lib soap to 100 gallons water. Probably the most serious of all are the fungus diseases, so that thorough spraying is necessary in order to combat them thoroughly. For control of brown rot, powdery mildew, rust, etc., of stone fruits, spray first with. Bordeaux, 8—6 —40, when the buds show pink, not earlier, following by a lime-sulphur spray, 1—125 when three parts of the blossoms have "fallen, again when fruit lias set with lime-sulphur, 1—125, and again 111 about four weeks with lime-sulphur, 1—125. For black spot .and powdery mildew on apples and pears, apply 8—6—40 Bordeaux _in the open cluster bud, following with saime sprays as mentioned for stone fruits.

As it is the earnest endeavour of the Horticulture Division to assist growers in combating diseases atacking fruit trees and plants, any further information required will be willingly given on application to the Government. Orchard Instructor, Department of Agriculture, Palmerston N.