HORTICULTURE

New Zealand Journal of Agriculture, Volume 54, Issue 3, 20 March 1937, Page 186

HORTICULTURE

Vegetable Crops.

One of the modern problems in vegetable-growing is the maintenance of a sufficient supply of humus, in the. soil under a system of constant and intensive cropping. In the past this has been done satisfactorily by applying heavy dressings of stable manure at suitable intervals. Such supplies are now not available, and, where no effective substitute is used the soil becomes, more or less, a dry lifeless dust, or, in wet weather, a sticky paste in which good crops may not be grown even with the most generous and wellconsidered mixture of artificial fertilizers. Even on the farm, in the warmer districts especially, little or. no ■ stabling is done, and well-cured animal manures for this purpose are scarce. On the lighter soils the problem of maintaining fertility is often best met by sowing down the land in grass and clovers, and grazing it for three years before breaking it up again for cropping for a similar period. On limited areas of high-priced heavy land this solution is not acceptable,- and the question remains as to how this demand can best be met. . . ■. .. . ' '. ■ ‘

Where the land is adjacent to a sea-beach where seaweed sometimes accumulates,-that material should be used, as its value for the purpose is comparable'with stable manure. Unless, however, it is conveniently placed the cost of collection and carting may render this supply uneconomical. Poultry-keeping is sometimes practised partly with the object of obtaining a supply of manure, and the method is always worthy of consideration. In very many cases the supply of humus has to be maintained by means of an inadequate supply of farm and stable manure supplemented by grass and other vegetation which may be harvested in the vicinity and fermented down, together with such green crops as may be grown on the. land and turned under. ■ . •

To make a compost heap of the class referred to, select a situation that is inclined to be humid rather than dry, and remove about i ft.' of soil from

a strip about 8 ft. wide and as long as desirable, placing the soil equally along each side. In the strip so cleared build the stack about 5 ft. or 6 ft. high as the material becomes available. Any vegetable or animal material that will decay in a few months is suitable. Build the stack firmly with straight perpendicular sides and “ damp down ” any dry material. Fermentation will soon commence, and the temperature will be sufficiently high to destroy most injurious organisms. Top off the stack with grass and weeds mown before they seed, during the month of December, in odd corners and headlands. Wet it as may be necessary, and then cover with the soil which was removed from the foundation. This may be kept in place by logs placed along the edge of the top of the stack and wired into position. When more material again commences to accumulate start another stack. If fermentation is slow an occasional dressing of sulphate of ammonia and phosphates will hasten it if the material is kept moist. As the main crops are now cleared the portion' of land selected for planting early crops during the months of July , and August should receive a. dressing of manure which is turned under. If 4 cwt. or so of basic slag or bonedust per acre and the . same quantity of kainit are worked in afterwards, the land should be in good condition for planting out salad and other crops in early spring. The kainit has the additional advantage of destroying slugs and other insect, pests which are often troublesome at that, season. ■ The remaining land as it is cleared, and so much of it as is not required for immediate cropping, - may be sown down in Algerian oats, bushels, and horse-beans, 1 bushel, per acre; or Cape or black baring.,and.vetches in the same proportions. These hardy crops in most localities will make good growth during the winter months, when the land can best be spared from commercial cropping, and provide in roots and tops considerable humus in the land when turned under to decay before further planting is done. They also have a beneficial effect in crowding out weeds, and so cleaning the land. Such land will usually be in good heart for the. growth of these green crops, but consideration may be given, to the application of a moderate dressing of fertilizers with a view to obtaining maximum growth. On small areas white mustard is sometimes sown. The crop is comparatively light, but still useful : it suppresses weeds and helps to prevent the waste of nitrates which may otherwise I be washed away if the land is left bare. It may be sown at a rate of about 2 oz. per square rod. The tomato crop at this season is often slow in colouring owing to low temperatures. If mature fruit is placed in. a temperature of 65° to 75 0 F. before or after packing it will redden perfectly. In a temperature over Bo° red colouring is retarded. Light is not a factor in the operation. T Mushroom-culture-has made considerable progress here recently. Beds 9 in. deep in sheds have given best results, and are also most economical with the limited supply of stable manure which is available. The main difficulty has been the control of extreme temperatures in summer and winter. To some extent it has been met by covering the beds with dry straw, but this method is inconvenient, especially where the beds are built in tiers to economize space. A well-built, insulated, and properly, ventilated shed- is no doubt the solution to-this difficulty. It also facilitates the control of insect pests, &c., by permitting effective fumigation and excluding much reinfection if the ventilators are screened. Continuous cropping can only be maintained where the conditions are under control and scrupulous cleanliness is observed in all of the operations. In a piece of clean, well-drained land the spring cabbage crop is now planted out. The plants should be set well, down to the first leaves and the soil carefully firmed about the roots, especially when using a dibber.

Cabbage, cauliflower, and lettuce plants are often sown during the month of April for planting out in early spring. In the cooler districts the protection of a cold frame is required. j '

Small-fruits and Sundry Crops.

Trials of varieties of hardy fruits for commercial purposes were started .at the Wisley Gardens of the Royal Horticultural Society, England, in 1922, under the administration of a representative committee, and examined at intervals by appointed judges. The most promising varieties were given a further test at sub-stations throughout the country. The first report was made in 1932, and the following are some of the outstanding results : Black Currants. position held by the four standard varieties (in •order of ripening), Boskoop Giant, Seabrook’s Black, Goliath, and Baldwin, is not immediately challenged. Daniels September is quite the best lateripening currant, and in some districts may rival Baldwin. Raspberries.— The three most satisfactory varieties in the trials were Lloyd George, Red Cross, and Pyne’s Royal, with Norfolk Giant as the most promising late variety. ' Red Currants. Earliest of Fourlands, Laxton No. 1, and Perfection were the best of a moderate entry. Gooseberries.— Leveller and Lancashire Lad are the standard varieties. Many entries were planted late and were not sufficiently established for judging commercial qualities at the time of the report. Leveller is' a fairly vigorous plant of spreading habit, with large oval dessert fruit, yellow-green in colour, and practically smooth surface. A heavy cropper and excellent quality. Lancashire Lad is a large oval culinary fruit, dark red, with hairy surface when ripe, but useful for harvesting in green state. Growth upright in habit; a heavy bearer. Raspberry Lloyd George has been planted in many parts of the North Island, and has given great satisfaction, looking very much as if its triumphs elsewhere were to be repeated here. But it cannot be too strongly stressed that commercial plantings should be done only with varieties of small fruits that have been proved suitable for one’s locality and market. The above lists, however, contain interesting, suggestions for .further trials in localities where fruit of this class is grown. Crops of this class, harvested as they are about mid-summer, require a moist, well-drained soil for commercial cropping, gooseberries and red ■currants being to some extent exceptions. A somewhat open situation is also desirable, but in this respect black currants are the least particular. The preparation of the land should now be completed as soon as possible, so that it may settle down well before planting commences. A generous dressing of manure, including perhaps blood and bone manure, trenched in or double-ploughed, will be suitable. When these crops are established only shallow ploughing and cultivation can be done without ■serious injury to the crop. - As regards spacing, much depends on the quality of the soil and the vigour of the varieties planted. Usually the distance between rows is 5 ft. to 6 ft., but in extreme cases 7 ft. to 8 ft., more especially for large plantations where the bigger implements are used. The tendency of late years has been to close up the distance between plants. Raspberries are •often planted singly 1J ft. to 2| ft. apart in the row, and black currants 3 ft. For the first season or two the dwarfer vegetable crops can be .grown in the alleys if first care is given to the welfare of the permanent crop. On the farm a special area should be devoted to these crops with a view to providing supplies for the household. It would be most convenient if ■other permanent crops such as asparagus and rhubarb, also culinary herbs, &c., could be included. In this way the needs of the crops are best supplied, .and the management is most economical.

Where nuts are grown the grass under the trees should be mown, or the surface otherwise ' smoothed out in the most suitable manner to facilitate harvesting. Then as soon as the nuts are ripe the trees should be well shaken and the nuts gathered, repeating the operation at intervals as may be necessary. Leaving the nuts on the ground exposed to dews and rain

for but a short period, depreciates the appearance and quality. Even when gathered promptly the nuts should be cured by drying them off well before storage. This is done in a ventilated shed or in . the open, the nutsbeing placed in trays 6 in. or so deep with slatted bottoms, and well stirred from time to time. If curing is done outside, the trays should be stacked, and covered at night to keep them dry. When cured the nuts should be put over a riddle to eliminate waste and under-sized specimens beforemarketing. Nuts required for planting should not be dried, but stratified in damp sand or sandy soil until they are sown. The Homestead Garden. . In the flower-garden herbaceous plants now receive most consideration. Anemones, ranunculus, tulips, hyacinths, early-flowering gladiolus, are among the spring-flowering bulbous plants which are now set out ; alsowallflowers, polyanthus, pansies, &c., for a display at that season. These often take the place of summer-flowering annuals which are now going off. Sweet peas and other hardy annuals for spring flowering may be sown ; alsoadditions and alterations may be made to perennial herbaceous borders. The present time, indeed, is suitable for the periodical overhaul which isrequired to keep the herbaceous border in first-class condition, or that operation may be deferred until early spring. In new gardens where the borders after subsoiling or trenching have been given shallow cultivation for a few weeks to destroy the crop of weed-seeds-sufficiently near the surface for germination, and allow the ground to settle, herbaceous plants may now be set out. The effect is generally, best when the group of plants of each variety is rather large. Border carnations deserve special consideration for this work in seaside gardens. In a well-drained open situation they flourish amazingly and are attractive in every way foliage and flowers, colour, and fragrance. Autumn-sown lawns have had good rains, and should come away strongly. When the grass is an inch or two high it should be cut when dry with a lawn-mower which is well lubricated and carefully set. It is generally best at this stage to raise the knife as high as possible and set it evenly and firmly. If cutting is repeated when necessary the grasses stool out and a good turf becomes established before the winter season.

—W. C. Hyde,

Horticulturist, Wellington.