INDOOR GRAPE CULTURE.

New Zealand Herald, Volume LXVII, Issue 20496, 22 February 1930, Page 5 (Supplement)

INDOOR GRAPE CULTURE.

POINTS FOR ATTENTION.

The frequent and heavy rains experienced almost throughout tho whole growing season of the grapes have necessitated extra care and attention being given to their cultivation. Such moist, humid conditions have naturally resulted in exceptionally rapid growth, requiring almost constant work in keeping lateral growths under control. With most of the earlyripening varieties there should be little difficulty in obtaining well-coloured and

ripened fruit. It is with some of the latest kinds, such as Gros Colman and a few others, that are by no means easy to thoroughly colour and ripen, unless favoured by exceptionally fine, warm weather during the next two months. In growing these late varieties there is always a difficulty, particularly when they are carrying a heavy crop of fruit, in maturing and ripening the fruit before cold, unfavourable weather sets in. In growing these late varieties without the

aid of artificial heat they should be started as early as possible in the season, to allow of them being grown without any unreasonable amount of forcing, so that they will be thoroughly coloured and ripened before the end of March. After that time it is almost hopeless to expect the fruit to properly mature, as the decreasing temperature and increasing moisture tends more to the decay of the berries than to their ripening.

It is natural that growers of late grapes want to keep the bunches as late as possible, or until the highest market value can be attained. To do this, however. the fruit requires to be thoroughly coloured and ripened. Well-ripened fruit can, with careful treatment, be kept hanging on the vines for weeks, providing the vines and foliage is healthy and free from disease.

PROTECTION OF LATE CHOPS. To keep grapes late in the season in a sound condition a comparatively dry atmosphere is essential, and it is almost impossible to maintain a dry atmosphere when the floor of the house is composed of damp soil, but if the floor is composed of concrete or asphalt the temperature can be much better regulated, only during the autumn, when the fruit is ripe, but during the whole growing season of the vines. In addition to this a much cleaner and more healthy atmosphere can lie maintained.

During moist, humid conditions, free ventilation should bo given. In this, however, care must be exercised to avoid sudden draughts or extremes of temperature. Every effort must be made to keep the foliage ia a clean, healthy condition, as it is upon the healthy condition of the foliage that the success of the crop depends. Every means must be taken to keep the mealy bug under control. By fumigating tbo house with the hydrocyanic gas every three or four weeks the vines can be kept comparatively free from this pest. To be thoroughly effective, however, the work must be judiciously performed, so that the gas is distributed in every part of the house. Before fumigating all soft sublater.il growths should bo removed. These, in fact, should in no case be allowed to accumulate, but should 1,0 removed from time to time, as they

BED SPIDER AND MILDEW. Other pest 3 that vine growers have to contend with are red spider and mildew. So far the red spider has given little trouble this season, the result, no doubt, of the moist season experienced. But although the excessive moisture is detrimental to the growth and increase of this pest, snch conditions are often the cause of mildew attacking the vines. In far too many instances, however, it is the result of excessive moisture at the roots. In seasons such as the present the advantage of having the borders thoroughly drained can be fully realised, particularly where the vines are planted in soils of a stiff, retentive nature, with little or no provision to take away surplus water. Under such conditions success could scarcely be attained, no matter how skilled and careI ful the operator may be with the indoor j treatment.

Whether mildew has made its appearance or not, sulphur should bo freely distributed through the house, as prevention is better than cure, for if once mildew is allowed to attack tho foliage it is by no means easy to eradicate. But should the foliage or fruit become attacked there is no better remedy than dry sulphur carefully dusted over the foliage or fruit affected, while it i 3 also one of tho most effective means of keeping red spider under control.