Vegetables, Small Fruits, and Flowers.

New Zealand Journal of Agriculture, Volume 57, Issue 6, 20 December 1938, Page 543

Vegetables, Small Fruits, and Flowers.

Contributed by the Horticulture Division.

Maintaining a Supply of Humus in the Soil.

T TND.ER: a system of intensive culti/J. - yation system of intensive - vation the supply of decayed ■■■>' animal and vegetable matter in the soil —known as humus-is lost in a few years, chiefly by means of oxidation brought about ,by frequent cultivation. Not only are the plant foods lost, but the physical condition of the soil is seriously affected. Where a good supply of humus is present the soil is rich and friable and has remarkable water-retaining powers.- ■. In its absence water is released rapidly and completely and the soil is reduced to harsh intractable clods, which, when broken down, form a dust in which there is little of that bacterial activity which is such an important feature in a really fertile soil. .. .A few crops and other plants may be grown without humus, if the physical condition of the soil is dealt with satisfactorily—a very difficult accomplishment—but in commercial cropping, and with the majority of garden plants, the maintenance of a supply of humus is indispensable to success. In the plantation and shrubbery, planted in land in fair condition, the supply of humus is maintained reasonably well by means of the annual f all of leaves and litter. Further, in the orchard a herbaceous crop may be grown and ploughed or disked in with little interference to the management of the trees. It is in the management of crops of that large class of plants known as annuals that the difficulty chiefly arises where they are grown intensively.Three Methods. There appears to be three ways of dealing with the problem. The first is to grow one crop per annum, and as soon as that is cleared to sow the land down in a suitable cover-crop for ploughing under before a marketable crop is planted again. This system is adopted by some tomato-growers, who have carried it out for a number of years with fairly good results. ....

'’ Where .cropping is more intensive and it is' necessary to harvest two or even three crops from " the same land each season it is necessary -to sow the land down in .grass after about three years of this treatment and to - graze it well with farm stock for a similar period before breaking it up again for cropping. During the grazing-period most of the plant diseases will be eliminated and humus ■ will accumulate. The third method is to apply dressings of well-cured manure as may be necessary. It should be ' clearly understood that artificial fertilizers will not take the place of this dressing, ’ just as-manure cannot do the work of artificial fertilizers. Both are indispensable to • obtain the best results in commercial’- cropping over extended periods on the same piece of land. Obtaining Supplies. In a country with a mild climate where -little stabling-is done it is often difficult to obtain the necessary supplies of manure for the operation of - this . method. A considerable amount is available from pig-pens, fowl-houses, stables, cow-sheds, and shearing-sheds, but it is frequently allowed to become a nuisance instead of being treated as a valuable product. • -.Where.’ straw is used for stabling the manure it can be stacked to allow it to cure-before it is applied to the land. In its absence, as is very commonly the case, a pit protected from the weather is required, or a concrete bin with one side planked up. The material should be accumulated in this, spreading it carefully so that.filling will be done evenly. In addition-to the materials mentioned, practically any kind of organic waste may be included as long as it -will decay . within a reasonable time. Specially useful are rough, grass and weeds found growing along hedge bottoms and in waste and vacant places. Cut with a scythe or horse-mower before the plants form seeds, the material should be stacked

with the manure, ..when bacterial action will soon reduce it . to a decayed state suitable for the land. There is also the advantage in this way of keeping ..weeds under control, in which lies very many advantages. . . . Quality Improved. In cases where the supply of humus in the soil is maintained by either of these methods and moderate quantities of artificial fertilizers . are used with discretion the quality of the crop especially is improved, the danger of loss from disease is greatly reduced, and the land is kept in good heart. Harvesting Onions, Shallots, and Garlic. These crops, grown from sets planted in early spring, now begin to ripen. In the drier and cooler districts the operations of harvesting are not so urgent as in the warmer localities, especially where they are also humid. In such places the indications of ripeness are not so marked, and a second growth very quickly makes its appearance and spoils the keepingqualities of the bulbs. Under such conditions it is important to watch the crop closely. . The first sign of maturity with onions is the plant, falling over just above the bulb, , and, in the case of shallots and garlic, the foliage .begins to turn , colour. By lifting the crops in fine .weather soon after these • indications. are noticed the keeping-qualities of the bulbs can best be' preserved. The bulbs are placed in windrows to dry off, . and as soon as this is accomplished they are trimmed with shears and carted to a cool, well-ventilated shed to cure. During this process the bulbs harden up, and if it is done with care to avoid bruising the bulbs will keep for a maximum period if they are afterwards stored in a dry, cool, ventilated place. • . Humid, close conditions ruin the quality of the bulbs and induce growth, if not

decay. They may be stored on slatted . shelves, in open-mesh bags, or slatted cases. For choice bulbs the best method is to leave the dry tops on and braid them into strings and hang them up in a suitable place. Condition is thus maintained, and the life is greatly lengthened by this method. The shallots are of mild flavour, and are specially suitable for sauces and pickles. Protecting the Late Potato Crop. Troubles which sometimes threaten this crop are late blight {Phytophthora infestans) and potato moth (Phthorimea operculella) . The late blight is a fungus disease especially prevalent . during warm, humid weather, when it sometimes causes serious loss unless a Bordeaux spray is applied promptly and repeated at intervals of about two or three weeks, as may be necessary. A strength of 3-5-40 is often sufficient— is, 3 lb. bluestone, 5 lb. hydrated lime or freshly slaked quicklime, and 40 gallons water. In more serious attacks a stronger mixture may be applied, as, for instance, 4-4-40, or even stronger still. The plants must be well covered by means of a fine spray, taking special care to cover the under-side of the leaves. The first appearance of the disease is usually darkened areas on the edges of the leaves, which quickly spread until, when conditions are favourable to it, the whole plant is blackened. Some protection is afforded the tubers if the moulding-up is done well and the soil is brought up to a sharp ridge. The potato moth is most active in dry, hot weather. Good moulding-up affords a measure of protection for the tubers. An application of arsenate of lead will also destroy the caterpillar larvae before they penetrate the tissues of the plant. Both of these troubles are propagated by sowing infected seed or leaving infected tubers or potato waste lying about. By practising hygienic methods, good culture, and spraying as may be necessary , there is usually little loss from these causes. As these diseases spread rapidly in storage, infected stocks cannot be held for any length of time, but must be consumed promptly. . > Vegetables for Sowing and Planting. Important crops for planting during January are savoy and red cabbage, kale, broccoli, cauliflower, leeks, and celery. Sowings may be made of turnips,' globe beet, early carrots, and salads. In the colder districts spring cabbage is sown towards the end of the month, but elsewhere during February. In warm districts a sowing of peas (an early maturing variety) will provide a late crop, as also

will dwarf beans. Spinach may be sown in a rich soil in a sheltered position. Runner beans in a dry position, as on a wall, should be sprayed well with clean water during the evening and the ground kept well watered. If this is done there will be less complaint that the beans are not setting. . ' ' . Treatment of Small Fruits. As the harvest passes, brakes of small fruits should be cleaned up, or, if their career is finished, pulled out and burnt. There are far too many brakes of bush fruits aged and diseased on which sprays and manures are wasted ; they are merely a source of infection, and are quite unprofitable. Before that stage is reached new plantings should be made on fresh land, so that when one crop has to be removed another comes into profit. .When the berries have been gathered the old canes of raspberries and loganberries which have borne the crop should be cut close to the surface of the ground and carried out and burnt. The new canes for cropping next season should then be sprayed -with a suspension of arsenate of lead to protect them from the attack of the native bud-moth (Carposina adreptelld), which often does serious damage by destroying the buds during autumn and winter. In black currants, also, the wood which has borne the crop should be cut low, just above a bud. * The . new wood produced this season will carry the next crop. Land for planting berry fruits should be taken in hand as soon as the early potato or other crop is cleared, and the land thoroughly cleaned and prepared for planting strawberries as soon as the plants are available, or hard-wood plants about the month of May. The varieties should be chosen with the greatest care, choosing mainly those which have proved themselves in the locality, with perhaps, in addition, a few plants of a promising new .variety for trial. The plants should be of medium size, well rooted, and free from disease. If they are not grown on the place they should be located and ordered now. Selecting Trees and Shrubs for the Homestead Garden. Furnishing the garden affords exercise for skill and taste if it is to be effective. It will be successful if it harmonizes with the surrounding landscape and generously provides the services expected of it both in utility and attractiveness. It is a mistaken approach to the problem to descend too quickly into the detail, instead, first of all, of deciding on the height, breadth, and situation of the main masses of vegetation. When these are

realized and acted on such mistakes as having shelter-belts too high and too close to buildings will be avoided. Not only must plants be of a suitable size and habit for the position they are to occupy, but it is also important that they be eminently adapted to the climate, soil, and situation in which they are to. be planted. For instance, in decidedly high country most of our conifers thrive exceedingly well—spruce, fir, pine, cedar, larch, &c.—and also our principal deciduous trees, such as poplar, willow, oak, sycamore, birch, &c., which ' brighten the autumn months. They also grow well in the colder districts. Flowering Shrubs. In warmer localities, especially in those which are humid, the very large number of evergreen trees and shrubs naturally grow well. They include most of our native plants, : which are not excelled in this class by trees from any country, and also the many species ■of cypress and eucalyptus; ? Most of our flowering shrubs require a moist soil and a somewhat shaded position, but others suited to a dry, sunny locality include the Acacia varieties, the native Pittosporum eras si folium, Spartium junceum, Ceanothus varieties; Cistus (“ gum ” cistus), Cytisus (the “ brooms ”), Callistemon varieties, ■ Nerium oleander, Albizzia varieties, Myoporum, Arbutus, Leptospermum, Romneya, . Buddleia varieties, Dodonia, Metrosideros tomentosa (pohutukawa), and Tamrix species, and also Agave, Aloes, and succulent plants generally. . Further, these plants are mostly suitable for seaside planting where, if the ground is moist, the fan-palm, species of Chamaerops, may be included, and also .in warm localities, the palms Phoenix canariensis, and W ashingtonia filifera. In the poorer sandy lands by the seaside the Monterey pine and cypress (Pinus insignis and Cupressus macrocarpa'} also flourish, in addition to Pinus canariensis, P. maritima, and P. muricata. Selection of Plants. Selections of plants based primarily on their suitability for the local soil and climate will always give the best results if they are suitably arranged—an operation which affords the finest field for the expression of good taste. Planting schemes should now be carefully worked out, nursery stocks inspected, and the selection ordered for delivery as soon as they are available, which will be about May, which is the beginning of the planting season.

Wm. C. Hyde,

Horticulturist,

Wellington.