GLADIOLI AFTER FLOWERING

Otago Daily Times, Issue 22568, 11 May 1935, Page 21

GLADIOLI AFTER FLOWERING

The new corm 6 of gladioli must be given a i chance to plump up after flowering has finished, but there is no need, nor is it advisable, to wait until the foliage is thoroughly ripened before lifting. A start can usuallv be made about six weeks after the spikes'have gone, and every effort should certainly be made to get the conns in storage by the end of April. If, as is probable, the foliage is still green and full of sap. it is advisable to partially dry it off before cutting it away. This is best accomplished by hanging the corms in bunches, with the foliage intact, in a cool, airy shed, which is at the same time proof against early frosts. On no account must they be left lying in heaps or thickly-packed trays, for then the sappy foliage will mould, and the corms too, will be affected. The plants are hung with the corms uppermost, and the bunch is of small enough dimensions to allow a free circulation of drying air.

In a few weeks' time the foliage can be cut cleanly away an inch above the corms, which can then be cleaned, graded, and store J away for the winter months.

Throughout a close look-out must be kept for disease. This is a problem of increasing importance to the gladiolus grower. During the past few years the spread of the rot diseases, scab, and wilt has been alarming in its virulence, and yet, with concerted effort, these troubles could easily be kept in check. One point alone, namely, the ease with which fresh stocks can be propagated, from spawn and cormels, makes it nothing less than sheer folly to replant badly-diseased and worn-out corms. There is only one method of dealing with plants that have been attacked by the hisarium wilt, and that is by burning those affected without delay. This is best done in the growing season, just as soon as the trouble is noted. The fungus sets up a root-rot, and the natural result is an almost complete cessation of growth. Affected corms will never give satisfactory results, and, as the disease is often difficult to detect after the corms have been dried, they are frequently left to spread the disease

in future seasons. Although not a certain indication, brown discolorations on the base of the conn near where the new roots appear are generally associated with this disease.

Scab or neck-rot disease, which sets up a neck-rot of the foliage, is easily recognised on the conn by the round, dark brown, shiny depressions which have a definitely raised and light-coloured margin. Dry and hard rota, though totally distinct diseases, cannot be distinguished from each other on the corm unless by microscopic examination. Both appear in the form of doilt-cbloured spots, which, in storage, increase greatly in fiize and deepen in colour, in extreme cases either disease may progress until the whole surface of the conn is covered and mummified. In all three cases very badly-attacked conns are best destroyed by burning. Mild attacks should be treated by cutting away the affected parts with a sharp knife and then soaking the corms in a 2 per cent, formalin solution for two or three hours. It is, of course, necessary to remove the greater part of the husks from the corms before a thorough examination can be made. Even though no signs of disease have been present on the foliage, this should always be considered an essential. Inspection of the corms during the winter months will then be a matter of moments. Brown and hard rot often fail to show on the conns for some considerable time after lifting, and for that reason regular inspections must be carried out. The conns are best stored in shallow trays, and, to prevent the spread of disease to healthy Kpceimens, cool, dry, and airy storage conditions must be provided. A warm, damp atmosphere is to be avoided at all costs. Trays similar to those used for sprouting potatoes, and constructed with raised ends to facilitate placing one on top of the other, But at the same time allowing free circulation of air, will be found most suita.ble, and also economical in gpace where room is limited.

Diseased specimens, even after treatment, must, of course, be stored in separate trays, and should have some finelypowdered charcoal dusted over them to dry up the wounds caused by cutting away the diseased portions, and so prevent excessive bleeding. Another point—it is ngt advisable to save cormels and spawn! from diseased corms. Only the healthiest stock is worthy of progagation, and most varieties are prolific enough to provide ample material from just a few corms. Spawn should always be stored separately in shallow paper-lined trays, away from heat of any description, or the already tough skins will harden to _ a point which makes their germination in the following season extremely doubtful.

Many varieties show signs of deterioration after a number of years in the production of flat, hollow-centred, and obviously unhealthy, though not necessarily diseased, conns. These also should be discarded, and their pla«e taken by healthy young stock raised from cornels or spawn. Experience has proved beyond all doubt that a vigorous young conn, three or four years old, will give infinitely superior results to an old specimen, be it even twice the size._ ' The husks of the eorms are a fair indication of their health and strength. Oh young and vigorous specimens they are bright and clear in colour. Loose,, dark-col-oured husks invariably cloak disease or old and worn-out corms.

A considerable amount of shrinkage during the winter months is inevitable, and turning of the corms should be a weekly task, otherwise sweating will certainly take place, and will, in most cases, lead to the corms forming premature roots. This initial root growth is not that on which the conn will subsist during the following season. Jt makes only sufficient roots to maintain the growth of the new corm, which, when developed, sends out the far-reaching thong roots. Nevertheless, it is a very much mistaken policy to imagine that allowing the corms to form the initial roots during storage will do no harm. It 13 an expenditure of energy which should be conserved until after the corms are planted.—Lothian, in Amateur Gardening.