SPRAYING OF FRUIT TREES.

Manawatu Herald, Volume XL, Issue 1864, 15 August 1918, Page 3

SPRAYING OF FRUIT TREES.

(By G. H. Cunningham, Government Orchard Instructor.)

■ The orchardist to-day lias to contend with many diseases in order to grow fruit successfully. ' In many cases the grower has no knowledge of the proper spray to apply for any particular disease, and frequently uses a spray that is of no use whatsoever in combating the particular disease he is trying to eradicate. There are a number of men in the 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 growers (particularly those possessing small orchards) should be careful whom they employ for this most important work. Those who hold a certificate for spraying and pruning issued by the Horticulture Division can be relied upon. As a guide to disease control, we will divide the diseases affecting fruit trees into three groups — chewing insects, sucking insects, fungi. As chewing insects attack the foliage or fruit, it is necessary to cover the surface of the foliage and fruit with a compound poisonous to insects; for this purpose use Arsenate of Lead at a strength of 3!hs. paste, or 21bs, powder, to 100 gals, water (2 oz. to 4 gals.). Although this poison is harmless at this, strength to persons and animals, it is death to the following chewing insects: codlin moth, leaf-roller caterpillar, bronze beetle, and pear slug. For codlin moth apply the spray firs! as soon as most of the petals of the flowers have fallen, following with a further application every 21 days throughout the sea-

Sucking insects obtain their food by penetrating the tissues with their rostrums (beaks) so that poison applied on the surface of Hie plant would be of little avail in checking them. For control of these posts it is necessary to use a spray that will kill by asphyxiation, or by contact. Red oil is, therefore, the best spray for the following sucking insect^: woolly aphis, green aphis, scales, red mite, and mealy bug 1 Apply in the dormant season,- on apple and pears, using red oil 1 —12; on stone fruits I—ls.1 —15. As an early summer control for woolly aphis use a soap emulsion of black leaf 40, J —Boo, adding 111), soap to 100 gals, water. Probably the most serious of all arc* the fungus diseases, so (hat thorough spraying is necessary in order to combat them successfully. For control of brown rot, powdry mildew, rust, etc., of si one fruits, spray first with Bordeaux B—f8 —fi —40, when the buds show pink —not earlier —following by a lime-sulphur spray, 1—125 when three parts of (he blossoms have fallen, again when fruit has set with lime-sul-phur 1 —125, and again in about four weeks with lime-sulphur 1— 125. For black spot and powdery mildew on apples and pears, apply B—f8 —fi —40 Bordeaux in the open cluster bud, following with same sprays as mentioned for stone fruits. As it is the earnest endeavour of the Horticultural Division to assist growers in combating diseases attacking fruit trees and plants, any further information required will he willingly given on application to the Government Orchard Instructor, Department of Agriculture, I and C., Palmerston North.