THE ORCHARD.

New Zealand Journal of Agriculture, Volume XXVII, Issue 4, 20 October 1923, Page 262

THE ORCHARD.

Fruit-trees of various, descriptions will now be in the summer stages, with young fruits and heavy growth of foliage. The fruits advance very rapidly in size, necessitating repeated sprayings to keep them protected against attacks from insect pests and the multitude of fungus spores. The same applies to foliage, which is of quite as much importance to the welfare of the tree as the production of fruit is to the. grower. Every effort should be made to keep the foliage as healthy as possible. ■ Unless the fruit and foliage are kept well covered disease-prevention is almost impossible, -yet this must be done in such a way as to eliminate russet, burning, or other damage to either fruit or foliage.

SPRAYS AND SPRAYING

Arsenate, of Lead. is used for the control of biting and chewing insects such as cod 1-in-moth, leaf-roller, cut-worms, &c., and is used at the rate of 2 lb. (if in powder form) or 3 lb. (if paste) to 100 gallons water. To ensure the best results being obtained it is essential that all parts be thoroughly covered with the- spray. With the rapid new season’s growth this means repeated applications of not longer than twenty-one-day intervals.

Bordeaux Mixture (3-4-40) is used for the prevention and control of fungus diseases. As a summer spray for fruit-trees bordeaux should . be used with the utmost caution, owing to the liability of damage to fruit and foliage. Never in any circumstances should it be used unless tested and proved to be alkaline. It is not really necessary on apple and pear trees except for black-spot control, and should be used only when spot is either feared or present. Before application arsenate of lead may be added to bordeaux.

Lime-sulphur is used for the prevention and control of fungus diseases, young scale, mites, &c. -There are many forms of this solution, from home-made to the many brands of commercial manufacture. The solution varies in density according to manufacture, and should be tested for specific gravity in order to permit correct dilution. Recommended dilutions are always based on 33 0 Beaume. Whatever brand is used purity should be the main consideration first and every time, and concentration only a guide to dilution. A false concentration test can easily be established by adulteration with salt or sugar, both of which cause damage to . the trees and crop. Use at a dilution of 1 gallon to 100 gallons water for pip-fruits, or 1-125 for stone-fruits, and apply, sufficiently often to keep the. growth covered. Lime-sulphur may be used in combination with arsenate of lead, but when so mixed a free acid is formed which must be neutralized by the addition of lime, or burning of foliage will take place ; 3 lb. of lime per 100 gallons will suffice.

Atomic Sulphur is used in particular for the control of powdery mildew, but is a very useful supplement to lime-sulphur for the control of brown-rot, and tends towards improving the texture of the foliage. ‘ When used alone 10 lb. .per 100 gallons is correct; when in conjunction with lime-sulphur 4 lb. to 6 lb. per 100 gallons. It may be applied with arsenate of lead and lime-sulphur plus lime.

Nicotine (40-per-cent. extract) is used for the destruction of aphis, leafhopper, &c., applied at the rate of 1 pint per 100 gallons. It may be mixed with arsenate of lead, lime-sulphur, and atomic sulphur, or the whole combined plus lime. If used as a single spray a spreading-medium is required, such as soap, 3 lb. per 100 gallons.

The present seasonal uses of the sprays would be as follows :—

Pip-fruits—Arsenate of lead, 2 lb. powder to 100 gallons ; lime-sulphur, 1 gallon to 100 gallons ; plus lime, if mixed, 3 lb. to 100 gallons (all three every 21 days) ; plus atomic sulphur, 4 lb. to 100 gallons, if variety is subject to mildew; plus nicotine, 1 pint to 100 gallons, if hopper or mealy bug are present. Bordeaux 3-4-40, alone or in combination with arsenate of lead.

—Lime-sulphur, 1 gallon to 125 gallons water; plus atomic sulphur, 6 lb. to 125 gallons water (one application of each during November) ; plus nicotine, 1 pint to 125 gallons water, if aphis is present.

CULTIVATION

Cultivation of the land should be continued. Where the land is heavy for the cultivator a very shallow ploughing may be done,- but the land should not be left rough any longer than necessary. .

THINNING.

Now that crops can be estimated, thinning may be done. Even where the crop is light it pays to remove all fruit from one- and two-year-old leaders in the interests of growth, and to reduce the number of fruits per cluster in the interests of thorough spraying and cleanliness of fruit. With a medium to heavy crop thinning pays every time. This practice is recognized by the successful orchardist as most necessary. Thinning allows all misshapen, underdeveloped, diseased, or injured fruit to be removed, regulates the crop from year to year, reduces to a minimum the production of culls and minimum-sized fruits, permits better colour, ensures more freedom from blemish, and does not overtax the tree or land.

No hard-and-fast rule can be laid down as to the number of fruits allowed to remain on the tree ; all is governed by the circumstances of tree condition, land, &c. As a general rule, all fruits should be removed from one- and two-year-old leader wood, all clusters reduced to ' singles, or at most doubles, and fruits removed from the extremities of unstable lateral wood.

—W. H. Bice,

Orchard Instructor, Hastings.

CITRUS FRUITS.

At this period citrus-trees should be showing considerable activity, especially those that have suffered in any way severely by frost damage ; and as warm weather will have caused scale and other sucking insects to be on the move it is desirable that control measures be adopted at this juncture. For this purpose the prepared red oils are recommended as a spray, to be used at the rate of i part of oil to 40 of water. Owing to the difficulty at all times experienced in covering the under-part of the foliage of citrus-trees with spray material it will be found advantageous to adopt the use of a spray-gun for this work. The larger, number of the young scale insects may generally be found on the under-side of the leaves alongside the leaf-rib, and these must be reached if effective control is to be obtained.

As citrus - trees that have been frosted come into activity growers will be enabled to see what portions of the damaged wood it is necessary to remove. Good clean cuts should be made when this work is undertaken, cutting to an outside shoot in each case.

Growers are advised to use those brands of red oil that have proved effective, rather than experiment with oils the qualities of which are, as yet, an unknown quantity. ...

STRAWBERRY-GROWING.

Fruit should be harvested immediately it ripens, not only to save depredations by birds, but also to prevent the taking of too much nourishment from the plant. Where necessary, spraying with Burgundy mixture for the control of leaf-spot may be continued, but it is not advisable to use this spray more often than is absolutely necessary. Watch for the appearance of runners, which should be pinched out during the fruiting season, before they grow too long and thus take nourishment from the plants.

Unfortunately, during the last few seasons a very unsatisfactory method of marketing strawberries has been adopted by quite a large number of the growers in the Auckland Districtnamely, the practice of " topping up ” the chips with larger berries than those which are contained in the lower parts of the container. This is to be discouraged in any shape or form, and it is hard to realize how producers can be so blind to their own interests as to continue the practice, which must necessarily reflect back to them from the consumer.

FIREBLIGHT

Any infection from this disease should be showing up at this time, and it is necessary that the very keenest lookout should be maintained, so that the diseased parts may be detected and immediately removed and burnt as already directed in previous notes.

— J. W. Collard,

Orchard Instructor, Auckland.