THE ORCHARD.

New Zealand Journal of Agriculture, Volume XXXIX, Issue 1, 20 July 1929, Page 55

THE ORCHARD.

SPRAYING.

Early next month will mark the beginning of a new season’s activities in the control of pests and diseases. As . this is one of the main factors in fruit-production, and success depends on months of well-directed effort, a brushing-up of one’s knowledge of control methods now will prove helpful. The spraying diary recommended by the writer some time ago, if such has been kept, might be studied also with the idea of putting into practice lessons it may have taught. Spraying-materials should be ordered, and the spraying outfit put in readiness. The overhaul of the spray outfit should be given a place of preference on the list of wet-day jobs during the winter. . Then the fruit-grading machine will require a good cleaning and the making of adjustments. Picking-boxes could be repaired and renailed,, and all implements cleaned and oiled.

A good working knowledge of the materials used in spraying may be gained from studying the Department’s bulletin on “ Control of Orchard and Garden Pests and Diseases.” The various materials recommended, and their uses, may be briefly summarized as follows :

(1) Poisons for chewing and biting. insects : Arsenate of lead is almost universally used for control of such chewing-insects as codlinmoth, leaf-roller caterpillar, and pear or cherry slug. . Fruit and foliage must be kept thoroughly covered with the spray, and applied in anticipation of attack.

(2) Contact sprays for sucking-insects : Red oil has proved most effectual for such pests as mussel, San Jose, and other scales, aphides,

pear-mite, thrips, &c., and is used towards the end of the dormant period or as the buds show some movement. Contact sprays are applied when the pest is actually present. Other contact sprays used • for certain purposes are lime-sulphur and Black Leaf 40. Lime-sulphur is very useful in the control of red mite and San Jose scale, mostly as a summer insecticide; it is, however, used chiefly as a fungicide, and as such serves both purposes. Black Leaf 40 used as an insecticide in the growing-period,, acting as a fumigant, controls such pests as -hopper and aphides.

(3) Fungicides for the control of fungus diseases : Lime-sulphur, bordeaux, and finely precipitated sulphur have their specific uses, and are employed in the control of such diseases as black-spot on apple and pear, leaf-curl on peaches and' nectarines, bladder or pocket, plum, powdery mildew on apples, shot-hole fungus on apricots, and brown-rot on stone-fruits.

Stone-fruit requires attention first, and the necessity for using an insecticide should be determined on the condition of the trees. Red mite and San Jose scale, if present, would require treatment with oil, making an application at 1-17 immediately before budmovement. ' It is necessary at this particular time of the year to select ■ a good sunny day for applying oil, so as to ensure better penetration into cracks and rough s surfaces. Where there is a heavy infestation of scale the only satisfactory means of dealing with it is to remove the heavily-infected branches and spray thoroughly the remaining portions. Badly infected branches located during picking operations should be marked at the time.

Bordeaux is used a little later, at a strength of 8-6-40, for the control of leaf-curl, shot-hole, bladder-plum, and peach-rust. This application should be made when the buds begin to swell. Delaying this spray till the blossom-buds are expanded may allow spores of leaf-curl and shot-hole to become active and infection to take place. On varieties liable to.severe attack a second bordeaux spray, at strength 3-4-40, may be applied when colour is showing in the buds. The practice of applying an oil spray following bordeaux is not recommended, as the application of oil so delayed necessitates such a reduction in ’ strength as to render it of little use, otherwise buds are damaged. Bordeaux may be applied following closely after oil if a spreader is used.

COMPLETION OF PRUNING

Pruning should now be well in hand, and every effort made to complete it before there is any movement in the buds. Any interference with the tree during the growing-period causes a check, and on weak trees is particularly undesirable: Trees which still appear too heavily spurred and which made but poor . growth should receive especial attention in the way of extra spur-pruning, ; so as to reduce the amount of blossom and encourage growth. . Heavy spur-pruning,-leaving the stronger and younger spurs, will frequently cause quite a burst of growth from fruit-spurs, and often gives better results than a drastic cutting-back of a tree that requires renovating.

All prunings should be gathered and burned as a sanitary measure in the control of disease. By using a pruning-sheet of

hessian or other material the gathering of prunings' is made easier and complete. A pruning-sheet requires to be a square, the side of which is equal to- the distance between trees, with an opening from the middle of one . side to the centre and bound on the edges. Two men working together can readily shift the sheet from tree to tree.

PLOUGHING AND MANURING

Where the ground is in suitable dry condition cover-crops should be ploughed in. Trees should be dug round before the spring to bury all leaves and rubbish. Most lands require occasional limings, and lime may be applied at any convenient time during the winter. Probably an average of 1 ton per acre every three years will suffice. It is better to spread the. lime prior to ploughing. Fruit-trees require annual applications of fertilizers if heavy and regular' crops . are to be expected. The general application of fertilizers may be deferred till nearer the spring. However, if slower-acting organic manures such as blood-and-bone are to be used, applications may be . made now with advantage.

REWORKING OF TREES

Many varieties which at one time were regarded as quite profitable to grow, having their particular virtues,' are now, through changed conditions, regarded' as inferior and unprofitable in the main. Such trees may be worked over to more suitable varieties by grafting. The operation is performed in the spring. Scions should be selected now, taking medium-sized last year’s growth and preserving them in good fresh condition by heeling-in in a place which is cool, shaded, and sufficiently moist but not wet. Trees which through overcropping, neglect, and other causes have become debilitated may be rejuvenated by working over in the same manner.

Trees intended for working over could now be cut down to within a few inches of the height at which it is intended to graft. This saves much time. in the spring if much grafting is to be done. The final cut is then made at the time of the grafting operation.’ The choice of variety is a matter which cannot be covered by a general recommendation. Local conditions, existing varieties in the orchard, and suchlike considerations must guide one largely, and it would be better to consult the nearest Orchard Instructor in regard to such an important matter. • —N. J. Adamson, Orchard Instructor, Hastings.

Citrus-culture.

Land may now be prepared for new plantations, careful consideration being given to providing adequate shelter and thorough conditioning of the ■ ground. Good drainage is the first essential. If the land is not of such a porous nature as to permit the excess water to percolate away readily under-drainage must be provided. Tile drains of suitable dimensions according to the length of drain are preferable, but if for financial reasons these cannot be provided, drains of logs and brushwood will give good service for some years. A thorough working of the upper subsoil is also advisable, but it

should be done uniformly over the whole area with a subsoil-plough, not merely by digging under where the tree is to stand. This latter method is bad practice, as it encourages the water to stagnate locally to the detriment .of the tree. General surface levelling should also be done while the area can be regulated without interference from trees. Throughout the whole preparation it should be remembered that. working the land when it is not in a fit state will have a compacting effect difficult to correct later. It is better to delay operations until the soil works, freely.

Varieties of lemons recommended for planting are as follows : Lisbon : The well-known variety of constant and early - cropping habit practically all the year round, but heaviest in late winter. Eureka: Quite as desirable and fruitful, as Lisbon; the tree is practically thornless, and the main crop carried in summer. Meyer : A recently introduced variety of special merit for domestic planting ; more frost-resisting than Eureka or Lisbon

Among preserving-oranges, the Poorman . yields a heavy and constant crop wherever citrus fruits can be grown. Medium to large fruits, the largest of which may be used for breakfast purposes. Season of harvest May to September.

In sweet oranges the following are recommended : —Navelencia : A good orange of late season. Valencia Late : A navel orange of late season. Lou Jin Jancy and Pineapple : Varieties of recent introduction with great promise ; they should be tried in a limited wa b- —W. H. Rice., Orchard Instructor, Auckland.