In the Orchard and Vineyard

New Zealand Journal of Agriculture, Volume 65, Issue 6, 15 December 1942, Page 361

In the Orchard and Vineyard

Orchard Notes

Spraying, Green Cropping and Harvesting Stone Fruit

WITH the advent of hot dry periods, insect pests become more troublesome. Codling moth and leaf roller caterpillar may do considerable damage to the maturing crops if spray coverage is inadequate during the summer months. Lead arsenate lg lb —lOO gallons of water should be applied at intervals of 18 to 21 days.

During this month a close watch should be kept for the first appearance of red mite and to prevent the increase of this pest, which may seriously debilitate the tree foliage, summer oil 1-100 should be applied and repeated in ten days if necessary. (Summer oil should not be applied within ten days of sulphur sprays).

Leaf hopper is especially troublesome in dry periods but may be readily controlled by adding nicotine sulphate 1-800 to one of the sprays being applied at the period when the hopper is in the nymph stage. As both red mite and the nymphs of the leaf hopper habitate the undersides of the leaves, care must be taken when applying sprays to ensure that the undersides of the leaves are thoroughly wetted.

der just when they come into flower. For ploughing under in autumn they should be sown in early January, and in late February for ploughing under in spring. From 1 to 2 cwt. per acre of superphosphate should be sown with the seed. On soils which are liable to scour during winter rains, it may be of advantage to let the green crop remain throughout this period and plough under in spring. As. this leafy crop acts as a dewatering agent of the soil it is of benefit to grow the crop during winter on waterlogged soils, and those liable to winter flooding. Wet soils carrying a green crop throughout the winter months are always in better mechanical condition in the spring than bare soils left unploughed or those left in fallow. Harvesting Stone Fruit December ushers in the commencement of fruit harvesting with the early peaches and plums. One of the difficulties with the early varieties is to se- .

In districts where ' ripe spot and bitter rot are usually troublesome, Bordeaux 1-2-50 may be substituted for ■the sulphur sprays from beginning of January. When Bordeaux is applied during the summer months a wetting agent is required to reduce the blotchiness of spray deposit on the fruit. A suitable wetting agent is casein. Thoroughly'mix while dry J lb. case with i lb. hydrated lime and shake gradually into a gallon of water while stirring vigorously; add to 100 gallons spray. Green Cropping The provision of organic matter is one of the surest ways of increasing the fertility of the soil. In many of our orchards soils the organic content has become seriously depleted due to years of intensive cultivation and lack of ploughing under of green matter. Build up the fertility of your soil by growing and ploughing under some satisfactory green crop such as blue lupins, field peas, vetches, etc. Blue lupins have proved the most satisfactory green crop for most conditions and types of soil and these should be sown at the rate of 1| bushels per acre. They are ready for turning un-

cure sufficient size in the fruits and heavy thinning is generally necessary in order to achieve satisfaction in this direction. Greater care is necessary in the handling of the stone fruit crop than with pip fruits due to the softer nature of the fruit and the greater liability of damage and consequent wastage. Tins which can be easily sterilised are the recommended picking receptacles. The stage of maturity at which to pick is determined by the time which is to elapse before the fruit reaches the market and the distance the fruit has to travel to market. Fully ripe fruit is soft, bruises readily, and will not stand transportation. Several pickings should be made, each time, harvesting only those fruits, which have reached the desired stage of maturity. Pick the fruit carefully and avoid handling fruits affected with brown rot. Affected fruit should be gathered separately and destroyed. During grading and packing the fruit should be handled with the greatest

care to avoid bruising. Firm fruit may be handled over the grading machine provided that the machine is clean, and free from grit and hardened dirt which would tend to mark and damage the fruit. With riper fruit many growers prefer to hand grade and pack direct from the picking tins. Typically coloured, well formed fruits free of disease and pronounced skin, markings should constitute the first grade. . When packing fruit for distant markets discard all bruised fruit and any with cracks, which

would be likely causes of decay. Wood wool protection at top and bottom of the case and correct height of pack should ensure safe carriage. Shed sanitation is one of the most important factors in satisfactory handling of stone fruit. The shed should be kept clean and all reject fruit removed and destroyed each day. Potent causes of rots affecting the fruit during transport are the spores of brown rot or other rots which I’have 1 ’have come from diseased fruit in the shed. Picking receptacles should also be kept clean and

diseased fruit should never be placed in them. Special containers should be used for gathering or holding fruit affected with rots and these should be cleaned and sterilised from time to time. The expenditure of care and attention during harvesting and packing will bring its reward through the fruit opening-up in better condition.

—R. G. I. HAMILTON,

District

Supervisor, Horticulture Division, Auckland.

Citrus Notes

Plant Nwiritian

. (Continued) ' Iron Chemical Symbol: Fe. Occurrence in Nature: An impure dorm of iron occurs in meteorites. Iron also occurs . as the oxideshaematite, limonite, magnetite, as the carbonate — siderite, and as the sulphideiron pyrites. , • Function: Iron exists in the plant in combination. It is essential for. the formation of chlorophyll, where its action

is regarded as catalytic. Its action is linked with that of potassium. Recommendations: Most soils, except white clays, contain plenty of iron. In the presence of calcium and manganese it is often unavailable to plants. It is necessary only in infinitesimal amounts. In its absence “chlorosis” develops and this can be cured by spraying with an 8 per cent, solution of ferrous sulphate. Iron deficiency is most common on calcareous or alkaline soils and therefore is not generally to be

found in the citrus-growing areas of New Zealand. Iron may be applied as limonite and occurs as a by-product in basic slag which contains 6 per cent, to 25 per cent, iron oxide. Manganese Chemical Symbol: Mn. Occurrence in Nature: Manganese does not occur free but as oxides, carbonate and sulphide. Function: Manganese plays a similar role to that of iron, i.e., it has catalytic action in the formation of chlorophyll. It inhibits the action of harmful bacteria attacking the roots, i.e., it is prophylactic. Recommendations: Manganese absorption is closely related to the pH of the soil. Lack of manganese occurs on neutral or alkaline soils; but on acid soils, rich in manganese, poisoning may occur through an excess of manganese absorbed. Legumes are most sensitive to a lack of manganese. The symptoms of manganese deficiency are similar to those of iron deficiency, i.e., chlorosis develops. The young leaves show a fine pattern of green veins on a lighter green background. On mature leaves the contrast between the two shades of green makes identification difficult, as the mature leaves may show no pattern and be entirely green if manganese is only slightly deficient. The size and shapes of the leaves may be normal. Manganese deficiency may occur on acid soils as well as on alkaline. Manganese is rapidly leached from very acid soils, so liming is advisable to bring the pH up to 6. Results have been obtained in the Auckland district by spraying with 5 lbs. manganese sulphate, 2J lbs. hydrated lime to 100 gallons of water, during the month of September. It is also applied as a byproduct in basic slag which contains 1 per cent, to 6 per cent, manganese dioxide. An application of manganese sulphate increases ammonification and nitrification. The action ,of manganese is linked with that of nitrogen..

Boron Chemicar Symbol: B. Occurrence in Nature: Boron does not occur free but as boric acid, borax and borates. ' Function: Boron is a prophylactic or preventive against disease. It stimulates the formation of the conducting' element of the root and promotes nodule - formation of legumes. In its absence calcium assimilation is reduced or inhibited. Recommendations: The absence of boron results in a browning of the internal tissues, e.g., internal cork of apples, brown heart of swedes, and similar diseases of tobacco, sugar beet, and cauliflower. The optimum quantity is 1 part in a million. In California 3 parts per million of soluble boron in the soil is harmful, yet a trace of boron is necessary for the proper growth of all citrus trees, 5 lbs. per acre is detrimental. Boron deficiency is generally associated with an alkaline soil and has been observed on citrus trees in Florida during drought conditions.

—A. M. W. GREIG,

Citriculturist, Auckland.

Don't neglect internal parasites in poultry. Full information is available in the Department’s free bulletin No. 19.

Cool Storage Notes

Overhauling the Refrigerating Plant

WHILE the. refrigeration plant is not in operation, and the storage chambers are emptied of fruit, a thorough examination of the ammonia compressor, condenser, and water circulating pump should be made by a competent refrigerating engineer. When the ammonia compressor is opened up for inspection particular attention should be given to—' 1. The compressor valves, valve sealings, and tension springs. 2. The compressor pistons, piston rings, and cylinders. 3. The main bearings, also crank and small-end bearing. 4. The compressor shaft or piston rod, and gland packing. 5. Scale and oil traps. 6. Stop valve and expansion valve spindles and gland packing. 7. The condenser pump, and replacements and repairs effected where required. 8. The double pipe condenser for detection of corrosion on the cooling surfaces, or ammonia leaks.

9. All piping should, be scraped free of rust and scale, and given a coat of a reliable anti-corrosive paint. , ' 10. The power unit and power transmission belting should be thoroughly overhauled. " The building timbers and insulation of both the chambers and battery rooms, particularly when malthoid has been used to protect the timber, should be thoroughly examined, as dampness from condensation often brings about a rotting condition in the timber at the back of the malthoid. If the building has been erected on timber stump foundation, it is advisable to examine these stumps just below ground level, as rotting of the stumps 'may be taking place. All cool storage repairs should now be under way, to have the whole of the equipment in good running order so that efficiency may be maintained throughout the coming season.

—A. A. POWELL,

Cool Storage

Officer, Wellington.