VEGETABLE GARDEN

Timaru Herald, Volume CXLIII, Issue 20669, 6 March 1937, Page 15 (Supplement)

VEGETABLE GARDEN

INSECT PESTS WHICH ATTACK VEGETABLE CROPS Diamond Back Moth (Plutella masculinpennis).—This is a pest which is not so very destructive in districts where there is an ample rainfall during the summer and autumn, but where there is a deficiency during these seasons it is very destructive. The adult moth is about a quarter of an inch in length when sitting with its wings folded. The prevailing colour is grey and brown, while on each wing there are three whitish triangular spots near to the hind margin. These meet when the wings are folded, and then appear like diamond-shaped marks along the back of the moth, the character by which the species can easily be recognised. The adult moths appear in November and December. The females then lay their eggs on any plants of the cabbage tribe, including I such weeds as charlock and hedge mus-

without staking iri all but the most windy gardens. L. candidum, the Madonna lily, is a good border plant which should be left alone when doing well, and when it must be replanted this should be done in early autumn. Lime rubble mixed with the soil will suit this lily. L. auratum, the golden rayed lily of Japan, is well known, and where it does well will grow up to Bft tall. The variety platyphyllum has broader foliage and a better construction. L. Henry! is a very vigorous Chinese lily growing up to nine feet tall with an immense spike or orange yellow flowers. This is a lime-loving lily and should not be planted in acid, peaty soil. L. Parryi grows to a height of four to five feet, bearing pendant funnelshaped flowers of pure golden yellow and very fragrant. It must have good drainage to keep the bulbs dry during the winter. L. Humboldti magnifleum grows to a height of from five to six feet, its flowers being pale orange with large dark crimson or purplish spots. A good woodland plant. L. pardalinum is a vigorous plant growing to a height of five to eight feet its flowers being various shades of orange or red, more or less spotted with brownish purple. One of the finest of all lilies for the stream or lake side.

L. Wilmottiae is a free flowering Chinese species of graceful habit. The stiff stems carry up to 40 large reflexed flowers or vivid orange scarlet. L. giganteum is the most magnificent of all the lilies. The flower stems are up to 10 feet in height, with a raceme of long white flowers flushed with purple and deliciously scented. It may take four to five years to work up a bulb to the flowering stage, and after flowering the old bulb dies. Young ones spring up round the old stem, and by planting a few every’ year there are always a few reaching the flowering stage. It is a good plant for the woodland or shrubbery. L. longiflorum Harrisii (Easter lily) is a wellknown variety extensively cultivated in Bermuda. L. speciosum in its varieties is a good plant for the autumn border, and Tigrinum is a well-known and old species suitable for the border. Other species and varieties are L sulphurgale, martagon Dalmaticum, Fortunel, Hansoni, Davidii, Washingtoniianum, tenuifoli Brownii, and chalcedonicum. L. Formosanum is a dwarf species with thin, grassy foliage and pure white flowers. This species is easily raised from seed, and seedlings will flower in the first year.

tard. The eggs hatch into caterpillars, which are green in colour, and live in a light web which they spin across the undersurface of the leaf upon which they feed. When full fed in about three weeks they spin small, white silken cocoons within which they turn into chrysalis. It is not certain how many generations there may be found in any month until the late autumun, if the weather remains dry.

Fortunately the moth has several natural enemies which help to keep it in check, birds destroying many of them. Watch has to be kept for the first appearance of the caterpillars, and the following remedies tried. As the caterpillars live on the under sides of the leaves and they are more or less protected by their web they are not easily got at by ordinary spraying. One method is to dust the plants (their food) very thoroughly with ground lime or lime and soot, and still better results are obtained by substituting a powder Insecticide such as nicotine powder. To secure the even distribution of the insecticide which is essential for success it is better to use a proper powder distributor rather than depend on distributing it with the hand. Wet spraying with arsenate of lead can also be carried out When the plants are young, but it would be a mistake to use a poison spray when they are almost fully developed and fit for use. It is also desirable to destroy all weeds of the cabbage family which may be growing about and which would keep on supplying broods of in-

sects ready to attack our cultivated plants. Cabbage aphis, which is slaty blue and attacks all members of the cabbage family, including swede turnips, is very troublesome in dry seasons, and is rather difficult to destroy. Like all other members of the aphis fami’y it breeds very rapidly and soon does considerable damage by sucking the sap out of the plants and causing the leaves to curl up. Spray with hot soapy water, to which some nicotine has been added. Dissolve half-pound of soft soap in four pints of boiling water, allow the solution to cool and then add three-quarter fluid ounce of 95 per cent."nicotine. For use take one fluid ounce of this mixture and make up to a pint with soft water. Spray carefully with this, and in a few days hose vigorously to wash off the dead or partly dead insects. LIQUID MANURE The manure should be placed in a small sack, and suspended in a large tub or tank filled with water. The liquor obtained must not be used neat. It should be diluted with water till it is the colour of pale straw. This weak solution has the great advantage that it can be used constantly in place of clear water, and hence the plants are encouraged to make steady progress, instead of being rushed on one week only to receive the severe check of semi-starvation the next.

But while natural manures, applied in a liquid state, have their especial value during hot weather, there is much to be said in favour of artificial fertilisers, applied dry when it is cool. It is not then desirable to water frequently, and if the use of liquid stimulants were continued the plants would then either go short of moisture or else necessarily receive more concentrated doses of plant food. Neither course is desirable. Dry chemicals, however, will be gradually dissolved by soil moisture, and, if applied regularly will keep up a steady supply of nutriment.

Great care Is necessary in the applications of such chemicals to delicate green-house plants. On no account should they be scattered haphazard all over the surface of the soil, as it is undesirable that any should come into direct contact with stems or leaves. Many chemicals are distinctly cSustic in effect, and may cause serious injury to naturally tender tissues. The right method is to apply the fertiliser with a teaspoon, and to spread it well away from the plant. When it is merely a cause of stimulating a plant in a general way. a balanced compound is much to be preferred to feeding with isolated chemicals. But there are occasions when other methods are desirable. For example, if the foliage of a plant shows distinct signs of yellowing, it is almost certain that it lacks nitrogen and possibly potash as well. In any case, it is wise to combine these two, as the potash tends to counterbalance the overluxuriance of growth produced by nitrogenous fertilisers alone. Sulphate of ammonia and sulphate of potash are the best chemicals to use. They may be mixed in the proportion of three parts of the former to two of the latter, and applied as a very light dusting to the soil. Sometimes a plant will make too much lush and succulent growth. It “runs to leaf,” to use a gardening expression. Here, again, is a chance for the unbalanced fertiliser. Superphosphate of lime is the chemical to use, and it may be applied in exactly the same manner as the compound recommended above. It is always essential to be careful not to use either liquid or dry manure in too strong doses; this is most frequently done in the case of dry chemicals. It is so easy to scatter a really heavy dose when merely applying the proverbial “pinch” of this, that, or the other. An overdose of, say, sulphate of ammonia will literally paralyse a plant; its leaves droop by degrees, according to the severity of the overdose, and if all are not involved at first, they will probably follow. The roots will be found killed. Unpotting, and removing the soil, and repotting in manure-free compost is the only remedy.