ORCHARD INDUSTRY

Wairarapa Age, 13 March 1929, Page 5

ORCHARD INDUSTRY

ADDRESS TO HIGH SCHOOL CLASS. AN INTERESTING SURVEY. PLANTING, PRUNING AND PESTS. In the course of an interesting address to the Wairarapa High School agricultural class yesterday, Mr. J. W. Whelan, Orchard Instructor to the Department of Agriculture, dealt with the planting and pruning of fruit trees and with the control of various diseases and pests. The class was in charge of its instructor, Mr. S. A. La Boche. In the opening passages of his address, Mr. Whelan told the boys something about the recent expansion and present prospects of the fruit industry in New Zealand. The industry, he said, foas becoming quite important. Last year, one million cases of apples were exported from this country —the millionth case, adorned ( with the fern-leaf brand, being presented to the Prince of Wales—and this year they hoped to reach the million mark again. The value of the fruit industry to the country was £1,600,000 per annum, £600,000 of that money being brought into the country in return for exports of fruit. During the last eight or nine years the industry had advanced by leaps and bounds. Once the export of fruit had been stabilised, there was no reason why the industry should not become as important as the export of meat and butter.

THE INFANT TREE. Demonstrating as he went with specimen young trees, Mr. Whelan said that it was very important that a fruit tree should be properly pruned during the first two or throe years, so that it might be correctly shaped. What was wanted was a tree open in the centre, with leaders spaced evenly all round. This shape admitted light and air, favoured good growth and facilitated very considerably the control of orchard diseases. Trees should be planted on a site

of northerly aspect on a slope if possible but in any ease on land well drained. 4 It was a great mistake to plant a tree that had been grown for more than two years in the nursery. An older tree suffered in transplanting from the damage to its roots. A common mistake in the first year’s plaining was to cut just a few inches off each leader. This had the effect of stimulating growth at the extremities of the tree and ultimately a meagre growth of fruit was obtained at these extremities, with much bare wood below. The proper way was to prune each leader three or four buds up from the main stem. The number of leaders depended very much on the growth of the' tree, but the leaders should be eighteen inches to two feet apart all round the tree. Starting with three leaders in the first year’s pruning, one, two or three might be added in the second year’s pruning, or it might not be possible to add any. It was advantageous, however, to have a few extra leaders to come and go on. Leaders should not start off from the same level. If they did, there was a danger that when the tree had grown and was carrying a load of fruit it might I split down. A tree that came from the ! nursery with two or more leaders start- . ing from the same level should be cont verted into a 11 whipstick” with a view . to the training of new leaders later.

> PESTS AND SPRAYS. , On the subject of pests, Mr. Whelan - said that the busy time in the orchard 3 was when the sap rose in the spring. - Nature at that time liberated all sorts ) of pests and diseases and the orchard- , its had to live practically with a spray - pump in his hand- Orchard pests and J diseases were divided into four classes: ’ (1} Eating insects, (2) sucking insects, (3) parasitic fungi and (4) bacterial s diseases like fireblight. As the most common and most injurious of the eating insects, Mr. Whelan instanced the

codlin moth. He detailed the life cycle of this insect and went on to state that the time to spray for all eating insects was from the period when 75 per cent, of the blossom petals had fallen. Arsenate of lead was used, and the aim of the orchardist was to keep forming fruit and foliage covered with a film of poison from the time the petals fell until just prior to the picking of . the fruit. Unfortunately, the weather sometimes interfered with spraying, but where it was kept going in the right conditions, the grubs of the codlin moth simply committed suicide, after they hatched out, by eating arsenate of lead. An old way and a good way of controlling codlin moth was to tie a bit of sacking right round the stem of a tree. The -,codlin grub, moving up the tree, found in the sacking band attractive winter quarters. If they were taken off about the middle of winter, the sacking bands would be found to con tain hundreds of codlin grubs. These could be destroyed by immersing the sacking in water for a few days. There

was no need to destroy it. This method was efficacious, Mr. Whelan explained, because the codlin grubs either fell to the ground in the apples into which they had penetrated, or lowered themselves to the ground by a silken thread. Later they climbed up the tree to take up . their quarters in readiness to be hatched out in the following spring. J Mr. Whelan spoke interestingly also of the leaf-rolling caterpillar, the pear slug, the bronze beetle and other pests. The bronze beetle when perfect, he said, attacked fruit trees, but at the pupae stage ate the roots of grass and was known as the grass grub. Horses had been known to sink to their fetlocks in land badly infested with this pest. No completely successful measures of pro- < tection against the bronze beetle had yet been devised. At the grass grub stage it was best dealt with .when land was being ploughed, by birds following up the plough. The best way to deal with a single tree attacked by the bronze beetle was to spread a sheet on the ground and shake the tree briskly. Hundreds of beetles would fall on to the sheet and could be destroyed. Mr. Whelan dealt also with methods of controlling sucking insects and other ■ pests, and in reply to a question by one i of the boys, made some interesting observations on fireblight which are re(ported in another column. At the close of his address, Mr. Whelan was thanked by Mr. La Roche and cheered by the boys.