HORTICULTURE.

New Zealand Journal of Agriculture, Volume 43, Issue 2, 20 August 1931, Page 144

HORTICULTURE.

An Insect Pest of the Raspberry.

The caterpillar larvae of the Carposinq adreptella moth has been very busy destroying the buds on new canes in many raspberry plantations during the past autumn. Specimen canes have been received during the winter months with most of the buds eaten put. The wood, apparently, is not to their taste, as attention is confined entirely to the widely spaced large dormant buds, which are eaten right out, and they are not renewed by the plant. As these buds normally push out and bear the fruit of the coming season, the serious loss of crop is readily imagined. Unable to bear a normal crop of fruit, the energies of the plant will be devoted to sending up a new crop of sucker canes. To save these from another serious attack from this insect pest is a problem the grower has to meet.

Although this insect is a native of the country, commonly attacking blackberry, we have little information regarding it beyond its identity. It appears to confine its attention to plants of the genus Rubus. Hudson states that the adult insectthat is, the mothappears from September to March. Presumably the moth lays its eggs soon after emerging from the cocoon ; the eggs hatch out in a few days, and the young caterpillars commence to feed immediately with their usual zest. If that is so, the crops are open to attack during the period of September to March inclusive. ■

For the first three months of this period the plants are in active growth, and the injury is not so mortal as that inflicted during the autumn, when, the dormant season approaching, growth ceases. Insect pests' which feed on plants during the dormant period are always specially destructive. The damage to the specimen canes sent in during the winter must all have been done since the month of December, when the new canes were practically just appearing through the soil.

This pest is widely distributed, and the present severe attack is a reminder that it is not to be regarded lightly. It provides another reason why arsenate-of-lead insecticide should be added to the bordeaux-mixture spray which is applied during the spring on the old canes, and in autumn on the new ones after pruning, to protect them from fungus attacks. 11 lb. of arsenate of lead in paste form, or fib. if used as a dry powder, should be carefully dissolved in a little water, then diluted further before stirring it into 50 gallons of bordeaux. To 4 gallons of bordeaux 2 oz. of paste or 1 oz. of powder will be a sufficient dose if it is well dissolved and then diluted before stirring it into the fungicide. Spraying should be done from the top downwards in a manner that will cover well the buds and angles in which they are placed.

The Tomato Crops.

The tomato crop will now be growing under glassin houses for early cropping, and in frames for planting out in the months of October or November, according to the local climatic conditions and market demand. A successful tomato crop depends very much on the way it is managed during the changeable spring weather. During the summer, when the weather is warmer and the plants well established, they require com-

paratively little attention if plenty of air is then admitted to the house in which they are growing. Any mistakes in watering, or ventilation now, however, quickly do damage that is almost irreparable. While stunting plants by chilling them should be avoided, it is almost as bad to grow coarse, sappy plants by keeping them too warm and moist. Thrifty growth, plenty of blossom, and a rather dry, buoyant atmosphere are what should be looked for at the present time where this crop is growing under glass,

For young plants now growing in frames for planting out later the period is also critical. Sturdy, clean plants may be grown now by giving tepid water sparingly and airing the plants promptly in warm, sunny weather. Damping-off disease and crown-canker are the. commonest penalties for mismanagement at the present time. The worst feature in these attacks is that many of the affected plants are not noticed until they have been planted out in the field some time and the disease has made some progress. Replacements have to be made, and .an uneven crop is one of the results.

Land on which the tomato crop is to be grown outside should be ploughed so soon as the previous crop is harvested. A good application of bonedust before ploughing and a dressing of lime harrowed in afterwards is suitable treatment in many instances.

Other Half-hardy Fruits.

Egg-plants and chillies are other half-hardy fruits of this class which are becoming popular, and may now be sown for planting out later. Melons, cucumbers, and even marrow plants may be raised under glass now in pots for planting out in a rich, light, moist soil. An early crop of small marrows is a choice crop that is usually in good demand.

Vegetable Crops.

During the changeable weather usually experienced at this season it is important to take immediate advantage of the drier intervals to hoe growing crops recently established, also fallow land that has to be cleaned in preparation for another crop. Such periods are also valuable opportunities for sowing seeds. A small hand-drill does the work expeditiously and well. It should be carefully adjusted to sow the seed thinly, so that little or no thinning has to be done afterwards, a laborious operation that greatly increases costs. On heavy land especially great care is needed to work it only when it is dry, and in some seasons these opportunities are so rare as to delay the work seriously ; but nothing is gained by breaking this important rule.

Plant now cauliflower, cabbage, and main-crop potatoes, and sow maincrop carrots, beet, peas, spinach, white turnips, and salads, .It is usually advisable to group the early-maturing crops, so that they may be cleared in time for planting the land with the important winter crops during the months of December and January. In preparation for this planting, leeks arid celery, seed should be sown towards the end of the month. For such half-hardy crops as French and runner beans, marrows, and pumpkins, which are sown outside in the months of October and November, the preparation of the land should be undertaken as soon as it is available.

The Home Garden.

The successful home garden depends chiefly on a tasteful arrangement and the good health and fertility of the plants. This applies with equal force to the lawns, which can usually be greatly improved by giving them ■some attention now in addition to the usual mowing. Most lawns are much improved by applying a dressing of sulphate of ammonia two or three times at an interval of three or four weeks, commencing the treatment now.

The latest recommendation is to mix three' pants sulphate of ammonia and one part sulphate of iron with twenty parts sand, break it down fine, mix it through a sieve, and apply 4 oz. per square yard. This will not only strengthen the grasses, but also destroy the weeds. Lawns on light land would-be' improved if they were rolled occasionally now with a roller of moderate weight. Combined with the fertilizing treatment before mentioned, this will go; a long way towards preventing the attack and remedying the effects of grass-grub. ■ . ■ Another pest of lawns, especially when the ground is usually rather wet, is the earthworm. The casts from the burrows spoil the appearance of the lawn, and when numerous they are detrimental in other respects. The remedy for this condition is a solution of bluestone (sulphate of copper). Dissolve 1 lb. with hot. water and dilute it up to 50 gallons. This should be applied to 100 square yards of lawn. The solution should be contained in vessels of wood, copper, glass, or stoneware, as tin or iron decompose the bluestone. Another important precaution is to apply the-solution in dull weather when rain threatens, and more especially towards the end of an afternoon. Under such conditions the pest is near the surface and more readily destroyed. Some of the choicer flowering shrubs are given special attention in the way of annual pruning. • Trees and shrubs which flower on wood formed last season should have that growth cut back, after flowering, to the buds at its base. This treatment encourages the development of the new wood for flowering next year. Heaths,' forsythias, diervillas, deutzias, philadelphus, rambler rose, lilacs, &c., are of this kind. The work should be done .so soon as the flowering period is over. , Another seasonable operation at the present time' is to repot such house plants as require it. If the pots are filled with roots and more growth is desirable, it may be obtained by shifting the plants into larger pots. Many plants may be divided, potted up, and so increased. Or the top soil may be removed and replaced with fresh and richer soil. In doing this it is important to make up a suitable mixture ; it should be composed of a good fresh fibrous loam that is rich and in good condition, sand to keep it open, and humus (preferably in the form of leaf-mould) to enrich it and give those qualities which enable the mixture to retain moisture, without which no plants can make much growth. A little bonedust, old soot, and wood ashes will also often be beneficial. Water the plants well shortly before the operation, pot them up firmly, and water very cautiously afterwards until they are well established. W. C. Hyde, Horticulturist, Wellington.

The Alien Flora of New Zealand.— Referring to Dr. H. H. Allan’s article on this subject in the Journal for June last, it has been found necessary, owing to pressure on space by matter of more immediate concern, to defer indefinitely the publication in the Journal of the proposed lists of alien plant species.

Current Horticultural Literature.— We have received the first number of Horticultural Abstracts, issued by the Imperial Bureau of Fruit Production, East Mailing, Kent, England. This publication has arisen in response to the express desire of horticulturists from all parts of the Empire, culminating in a resolution adopted at the First Imperial Horticultural Conference held in London, August, 1930. Its aim is to collect under one cover summaries of the more important current horticultural literature, special emphasis being attached to fruit-production, storage, and allied subjects. These summaries will be of sufficient length to indicate the contents and scope of the papers concerned. Each volume will consist of four parts, which it is proposed to issue quarterly. Price, is. 6d. per number, or ss. yearly, post-free.