General Maintenance Work

New Zealand Journal of Agriculture, Volume 60, Issue 4, 15 April 1940, Page 304

General Maintenance Work

Orchard Notes

APART from the harvesting of late varieties of apples—work which continues in some instances throughout May and into Junethere is little urgent routine work which requires attention during this period. Normally the harvesting work is not so continuous as in the preceding months, and time may be available for giving attention to maintenance work of a general nature and jobs which require doing periodically. It is too early to start pruning, as defoliation is not sufficiently advanced, but time may be well employed by giving attention to drains and shelter belts. Orchard Drainage On flat land with insufficient natural drainage improved drainage becomes a matter of first importance if maximum tree development and production is to be secured, as fruit trees suffer severely if the water level is allowed to remain too high for a lengthy period. Exceptionally wet periods from time to time have disclosed weaknesses in a good number of orchards, and have pointed to the need of more drains or deeper drains. Existing drains require attention by cleaning the open drains and freeing the outlets to covered drains. Trees which have become stagnant in growth or have failed to gain full stature through water injury will make a recovery and renew their growth once the drainage has been made adequate. Roots will penetrate deeper without injury later, and trees will not suffer so much in subsequent dry periods, as is the case when rooting has been kept shallow. It is an advantage to have this work done before the winter rains set in, when land remains wet for relatively longer periods. Shelter Belts Although shelter for orchards is very necessary and in most orchard districts

some shelter belts have to be provided, it is important that they be kept under control. Excessively tall shelter for relatively small areas ’ may cause excessive shade and keep a wide strip of land excessively dry, resulting in a much greater loss in production than is likely under normal conditions without the full amount of protection. In an area which is too confined conditions are created which, favour the development of fungus diseases, „ particularly powdery mildew of apples. When Lombardy poplars are used they should be brought down to a reasonable level at regular intervals, as they increase in height so rapidly and have proved very exhausting. They should be brought down .to a height of 20ft to 30ft every three years. In order that the work may be spread it is a good plan to undertake a third each year; otherwise an undue amount of time may have to be employed in one year and some . other essential maintenance work suffer. . - Ploughing and Manuring Deep ploughing of the orchard at least once a year is advisable, and to gain the most beneficial results it should be done in the late autumn. The action of rain and frost so improves the physical condition of land, especially heavy land and clay soils, that the desirable good tilth early in the spring is more easily attained. For most orchard lands requiring manures it is necessary to apply a complete ration consisting of materials containing phosphoric acid, potassium, and nitrogen. Phosphoric and potassic fertilisers are best sown before the deepest ploughing, which may be in the autumn, but nitrogenous chemical fertilisers should not be applied until the spring.

Normal applications of fertilisers on the poorer soil types, which constitute a fair proportion of the total fruit area in the Dominion, would be 4 cwt. superphosphate, 2 cwt. sulphate of ammonia, and lj cwt. potash per acre, or alternatively, 6 cwt. of blood and bone with the additional potash. Late Spraying Of Peaches If opportunity offers it is an advantage to spray peaches with Bordeaux mixture 5-4-50 at “leaf-fail.” Some varieties which are recognised as being very subject to leaf curl often require two applications of a fungicide before bud-movement of leaf buds to secure complete control. Broken weather in the spring may make it difficult to spray according to plan. An application at “leaf-fall” will satisfactorily take the place of a spray at “budmovement” and, having been applied, makes the position more secure in the event of any delay. Harvesting Late Apples The main variety of apples still to be harvested is the Sturmer. It provides a very large percentage of the total apple crop, and is grown by almost every apple grower. It will be cool stored to a greater extent than any other variety, and quantities will have to be retained in ordinary storage for a fair period. Careful handling is essential to secure the best results. Freshly picked Sturmers take on small bruises readily, in addition to grader markings. A space of three or four days between picking and passing over a grading machine allows for just sufficient toughening of the skin to prevent much of the marking . which would otherwise occur unless extreme care were employed.

Fruit for long cool storage is best taken from the main picking. It may be necessary to delay delivery of part of the Sturmer crop, in which case the smaller and less mature fruit could, with advantage, remain for a late picking.

Ripe-spot will appear if picking is unduly delayed, but growers should keep the remaining crop under close observation to avoid any damage in this way. The best possible orchard storage conditions should be provided to pro-

long the storage life as much as possible and at the same time avoid wilt. Earlier notes have dealt with this aspect of orchard storage. .

—N. J. ADAMSON,

District

Supervisor, Nelson.