THE ORCHARD.

New Zealand Journal of Agriculture, Volume 47, Issue 5, 20 November 1933, Page 323

THE ORCHARD.

Seasonal Spraying. The combination spray recommended for use in last month’s notes for control of black-spot, powdery mildew, codling moth, &c., up to mid-December, should after that period be substituted by the following : Lime-sulphur 0-083 per cent., plus colloidal sulphur 2 1b. ; lead arsenate . 1J lb. powder (or 3 lb. paste) per 100 gallons water. Continue applications according to climatic conditions. In normal circumstances from fourteen to twenty-one-day intervals should suffice. In those districts, however, subject to fogs or heavy dews, or should showery to wet days set in, the period between sprays should be reduced accordingly. When applying any spray thoroughness should always be the main object, and from now onwards, owing to increased density through the trees being in full foliage and possibly carrying their full complement of fruit, the need for greater care and thoroughness arises. As mentioned in previous notes, spraying can only be 100 per cent, efficient when every part of the tree and its appendages are not only thoroughly covered but applied with sufficient force to drive the spray into every corner and cavity present on the tree. Lack of thoroughness and care in this direction may cause serious monetary loss by leaving some of the tree parts uncovered and thus provide an opening for disease to attack and spread at will. A careful watch for black-spot should be kept from the time the leaves unfurl from the bud. Soon after this stage of growth the disease may be expected to appear in the form of small scattered spots on the under surface of the leaf, while a little later the embryo fruit may show the first sign of attack on the calyx and pedicels. In making up 0-083 P er cent, lime - sulphur mixture, if the polysulphide content of the brand is “ 12 ” the correct dilution is 1-144 ; if “ 15,” 1-180 ; if “ 18,” 1-216, &c. Continue spraying pears with bordeaux 3-4-50 for control of pear scab, as recommended in September notes. Thinning of Fruit. Apart from the removal and destruction of spot-infected fruits, &c., from the trees, thinning of applies should not be carried out until after the natural dropping which occurs each season about the middle of December. It is inadvisable to apply summer oil just prior to this occurrence, owing to the fact that such oil apparently intensifies the dropping action. Thinning is an operation which consists of removing from the trees all fruit which is imperfect, insect infected, diseased, overcrowded in clusters, and all surplus fruit which can well be dispensed with, and which it is obvious the tree is incapable of nourishing and bringing to profitable size. On the other hand, overthinning (which may easily result if the work is carried out before the natural dropping takes place) must be avoided, otherwise oversized fruit will result, which puts it out of bounds as far as export is concerned. Another object to be aimed at when thinning is to space the fruits so as to prevent them coming into contact one with the other ; . in this way the risk of injury by codlin moth and leaf-roller caterpillar, &c., is very much lessened, if not eliminated.

Judicious thinning not only increases size but also improves appearance. It thus pleases and attracts the consumer, commands a fair price even on a glutted market, and is more profitable to the grower. Small, malformed, and poorly coloured fruit, on the other hand, gluts the market, brings down prices, and more often than not does not pay for the handling. The foregoing remarks refer to the thinning of all fruits.

Grafts. Where top working of fruit trees has been carried out during the past grafting season it is a wise precaution to now look over the trees, and where good growth has been made to loose the binding without disturbing the scion or wax. The safest and simplest method is to sever the binding by drawing a sharp knife from top to bottom of it well away from the scion itself. No other action is necessary. Any surplus growths within reason which may have occurred can be allowed to remain, with a view to absorbing as much' of the surplus sap as possible, thus eliminating to a large extent the risk of silver-leaf (Stereum purpureum). Fireblight. A fairly comprehensive note was given last month on this subject. The danger period (blossom) for a general or wide infection will now be passed. However, the danger of local infection will be present as long as sucking and biting insects are allowed to move about at will. Fireblight is very much more virulent on pear than apple trees. Branch canker on the latter is not usual, infection being confined more to the blossoms and laterals. On pear trees, however, the organism spreads very rapidly to the larger limbs, and when this occurs there is little or no hope of saving the tree. Therefore it is recommended that such infected trees be taken out by the roots and destroyed by fire at the earliest possible moment. Cultivation. This important operation should not be overlooked on any account. Keep the soil well pulverized by harrowing, . &c., in order to maintain the capillary attraction of the soil, keep weeds down, and generally improve soil conditions, so as to give the trees every possible chance to thrive and produce a maximum of top grade fruit. When each implement used for cultivation is finished with for the season it should be stowed away in a dry shed in readiness for use when again required. The plough or any implements with a bright surface should be thoroughly greased so as to prevent rust setting in during the period they are not in use. This precaution will incidently save much time and annoyance when such implements are again brought into use. The easiest and simple , way is to heat a piece of unsalted mutton fat and thoroughly rub over such surfaces ,as mouldboards, &c. —J. W. Whelan, Orchard Instructor, Palmerston North.

Citrus Culture. As soon as the early spring rains have ceased and the weather seems more settled cultivation of the soil round the trees should be given attention, in order to conserve moisture as much as possible and assist the trees to function. Cultivation should be-such that a fine tilth is obtained, but should not be deep enough to disturb the surface-feeding roots. ,

Owing to the past winter having been comparatively free of severe frosts spring growth should now be well started, and any undesirable shoots may be rubbed out, which will save time later on. All newly planted trees should receive particular attention, and any water shoots which may be growing on the inside of the tree must be entirely removed, also all growths which may have started from below the original budding. A strong and vigorous tree must be aimed at, and this can only be obtained by building on a good foundation.

A careful watch should be kept for any signs of fungus disease. Prevention is better than cure, so an application of bordeaux 4-4-40 as soon as the main crop of blossoms has set will assist in the control of verrucosis ; and as the blossoming extends over a long period further

applications will be required as occasion arises. Should thrips be in evidence nicotine sulphate' 1-800 can be applied in ; combination 'with the bordeaux. .■ Scale insects should be dealt with as mentioned in last month’s notes

L Paynter,

Orchard . Instructor, Auckland.