The Home Orchard in Autumn

New Zealand Journal of Agriculture, Volume 94, Issue 2, 15 February 1957, Page 161

The Home Orchard in Autumn

THE bright colours of ripening fruit are a gratifying sight after the effort and care spent during the season. Routine work is required for the harvest season as well as for the others. In this article S. P. Money, Horticultural Instructor, Department of Agriculture, Wellington, discusses orchard hygiene, the harvesting and storage of crops, use of cover crops, and other seasonal work.

ORCHARD hygiene is most important during autumn, when much fruit is near • maturity. Diseases such as brown rot of peaches and plums or black spot of apples rapidly spoil a first-class crop. . Citrus During February and March citrus trees should be inspected regularly for scale and other insect pests. As infection is not always confined to the fruit,, careful examination of wood, foliage,

and fruit is necessary. A sure indication that aphids or scale insects are present is the appearance of a black, sooty film on the foliage and fruit. To control all insect pests trees should be sprayed with summer oil, 1 pint to 4 gallons of water. ' Passion Fruit During autumn the fungous disease grease spot is prevalent on the leaves and fruit of passion fruit vines. It appears on the green and the. purple fruit as greasy, brown, circular mark-

ings, which become . more noticeable toward the end of autumn and earlywinter. This disease causes defoliation, dropping of fruits, and destruction of badly infected vines. The application of bordeaux mixture 3 : 4 : 50 (4oz. of bluestone and s{oz. of hydrated lime to 4 gallons of water) at monthly intervals, especially between March and September, assists in checking this disease. Sunscald should not be confused with a disease of passion fruit, as it is not a disease; the light-brown

patches are usually caused by the fruit skin being exposed too long to the direct rays of the sun under still air conditions. This especially applies to fruit which has fallen to the ground.

Grapes

. Grapes are approaching full maturity in mid-autumn, and protection should be given against birds, which attack grapes in most parts of New Zealand. If the individual bunches are not covered, as is done by some home orchardists to get good quality, fruit vines on a low trellis may be covered with fish netting. Another method is to put a length of Jin. -mesh wire netting along either side of the trellis, the two top edges being tied together through or over the trellis.

Botrytis rot, a fungous disease, attacks bunches of grapes late in the season. Infection usually follows injury to the fruit caused by birds and insects or splitting of the fruit during wet weather. The disease appears in the bunches as a felty mass of grey mould, which rots the fruit. Control by spraying has not proved very satisfactory. At the late stage at which botrytis makes an appearance spraying would leave an undesirable residue. Apart from this, the waxy bloom on the fruit makes effective spray coverage very difficult. Enclosing of the bunches in suitable bags is the most effective- measure against botrytis. Thinning of the foliage to permit quicker drying of the bunches after rain reduces the incidence of botrytis, as does protection from bird and insect damage.

Strawberries

Strawberry beds for autumn planting should be prepared early in the season to allow the soil to settle before planting out is done. The area

selected must be well drained or raised to allow free drainage, as wet conditions are conducive to poor growth and root rot diseases. Strawberries are gross feeders and prefer a soil rich in humus. Before planting, a base dressing of manure consisting of plant foods which will become available over a fairly long period should be broadcast over the whole area and worked in with the final cultivation. This manure may consist of 3 parts by weight of blood and bone, 3 parts by weight of superphosphate, and 1 part by weight of sulphate of potash applied at 4oz. to Boz. per square yard. During the growing season applications of manures should be sufficient to maintain growth and fruit size. These dressings should consist of elements which will be available fairly quickly to the plants. A mixture of 3 parts by weight of dried blood, 1 part. by weight of sulphate of ammonia, 1 part by weight of superphosphate, and 1 part by weight of sulphate of potash should be applied at loz. to 2oz. per square yard. The first application should be made when the first blossoms appear and further applications where it appears necessary. The manure mixture may burn if it comes in contact with the leaves. Spraying with bordeaux mixture 3 : 4 : 50 (4oz. of bluestone and s|oz. of hydrated lime to 4 gallons of water) to control leaf spot of strawberries, currants, raspberries, and other brambles should be continued during autumn. Cover Crops In most districts cover crops can be sown successfully in autumn. There are many advantages in growing cover crops. Root systems of such crops, especially those of the grain types, are

very effective for improving the structure of the soil. When the crop is later turned in it contributes valuable humus material to the soil. One of the most important features of growing a cover crop is to allow enough time for the crop to mature and if possible to become fibrous before it is turned in. If it is a crop which does not dry out easily, it is important that it be left until it has “hardened” and the sappy nature of the new growth ,is past. The reason for this is that soft, sappy growth, before fibre has developed, is of little use to improve the soil when dug in. It has a high water content and is broken down by soil bacteria very quickly, so that spring rains can easily leach much of it out of the soil before the trees and plants can derive benefit from it. A crop which has been allowed to dry out or mature is much more useful. When this material is turned in the lasting mechanical effects of accumulating material aerate the soil through succeeding wet winters and provide moisture-retaining qualities during following summers, as it is more difficult for the soil bacteria to break down the hard plant material. Kinds of Cover Crops The three main types of cover crops are legumes, cereals, and brassicas. Legumes Legumes are generally preferable to other crops, as, beside the desirable qualities for a cover crop mentioned above, they are able to provide nitrogen through their ability to fix free nitrogen from the air in their root nodules. This nitrogen is released as the plant decomposes in the soil. Lupin is the most popular of this group, being very widely grown

HOME ORCHARD ... throughout the country. One disadvantage is that lupin is a slowgrowing crop which takes at least 20 weeks to reach a suitable stage for digging in. The young plants are very frost tender and must be sown early enough to allow them to become established before severe frosts occur. Successive crops of lupins should not be grown every year, as the plant is susceptible to a number of diseases, notably Sclerotinia sclerotiorum. Continued cropping could allow a build up of this fungous disease, which also attacks garden crops such as tomatoes and lettuce. Other legumes used as cover crops are field peas and occasionally red clover. Cereals Cereals are important for use as cover crops. Those most commonly grown are barley (Black Skinless and Cape varieties), Algerian oats, and ryecorn. The last-named is very widely grown as a cover crop in the tobacco areas of the Nelson Province. All are easy to establish and capable of producing a quick-growing bulk of

green material. Oats and > ryecorn particularly can be grown on a wide range of soils and under cool conditions. Brassicas ■ Brassicas are not nearly as important as legumes and cereals. The only brassica which is quite suitable f®r an orchard cover crop is mustard. It has the advantage of making quick growth and is ready for turning in before other crops, but the growth made is soft and sappy and decomposes very rapidly. No one type of cover crop should be grown continuously, as this can be responsible for increasing soil-borne diseases. One plan is to grow lupins for 1 year and two different types of cereal for the following 2 years. Some people grow a mixture of field peas and oats. The oats help to support the peas. This combination can be followed by a crop of ryecorn or some other cereal. Lupins and cereals can also be used in combination. Sowing To be of the most benefit the crop should be sown at a time when its

competition is least felt by the trees. The best period as far as the trees are concerned is after the fruit crop has been harvested, usually in late February to early March, but this is not practicable among mid- and late-season varieties of fruit. In dry autumns it may be desirable to delay sowing until after rain. On most soils phosphate is the most important fertiliser for cover crops. For cereals the addition of a small amount of nitrogenous fertiliser such as blood and bone or dried blood may be desirable. Superphosphate at loz. per square yard is sufficient for legumes, and |oz. of dried blood should be added for cereal crops. Recommended sowing rates for seed of cover crops are:— oz. per sq. yds. Blue lupin . . 1-2 3 Barley . . .. 1-2 6 Oats . . .. 1-2 6 Ryecorn . . .. 1-2 6 Mustard . . . . 1-2 60 The crop should be left to harden as much as possible before it is turned in, and a light dressing of blood and bone applied then will overcome the temporary shortage of nitrogen while the bacterial action is taking place.

Harvesting and Storage of Fruit

Apples and pears required for storage should not be harvested until they are fully mature. If young and old trees are growing together, it is best to use fruit from young trees first, as usually this does not store as well as fruit from older trees.

Apples and pears are mature when the seeds are brown or black but the flesh is still crisp and firm. .Fruit tends to mature first on the higher and more exposed parts of the trees; thus it may be necessary to make several pickings for fruit of even maturity.

Before it is stored the fruit should be sorted into large, medium, and small sizes, as the smaller fruit usually has the best keeping qualities. Any diseased, bruised, or damaged fruit should be discarded.

Shallow trays placed in racks in a cool, dry position are the best for storing fruit, for in trays fruit can be inspected without being handled and the risk of bruising .is reduced. If fruit cases are used, they should be lined with several layers of newspaper or a layer of corrugated cardboard. The cases should then be stacked so that air can circulate freely around them.

Cape gooseberries ripen in autumn and should be harvested when the husks change from green to a light straw colour. The berry at this stage also changes to a bright yellow. The berries do not ripen all at once and frequent pickings are necessary for reasonably uniform maturity.