LATE BLIGHT IN POTATOES

Press, Volume LXXXVIII, Issue 26887, 13 November 1952, Page 6

LATE BLIGHT IN POTATOES

WELLINGTON CROPS THREATENED EFFECT OF WARM, WET WEATHER (New Zealand Press Association) WELLINGTON. November. 12.. An outbreak of late blight, which is likely to reach epidemic proportions, is threatening Wellington’s potato crops, and may spread to the commercial gardens of the Wairarapa and Manawatu districts. Officials of the Department of Agriculture confirmed this today. Already once-promising potato crops in Wellington have become complete losses because of the blight. The Department of Agriculture warns gardeners, both amateur and commercial, that further warm, wet weather will bring a blight epidemic, unless the spread of the infection is checked by immediate spraying. To wait till the blight is evident is too late. Late blight is a fungus disease, and is well known to gardeners. It usually attacks potato plants after Christmas in the Wellington, Wairarapa, ana Manawatu districts, when the main potato crops have been gathered, and only old plants are in the ground. The prolonged spell of warm wet weather which the lower part of the North Island is experiencing, and which ig very unusual for this time of the year, is ideal for the spread of the blight. If the ’ blight spreads to commercial potato crops in the Wairarapa and Manawatu districts in this early stage of their growth, the position will become very serious. The symptoms of late blight are brown to black dead areas at the tips or margins of the leaves. These areas spread downwards, the rate of advance depending on the weather. The entire leaf my be killed in four days if moist, warm weather continues. Dry. hot weather slows up the advance.

To control the blight, potato plants should be sprayed with a strong Bordeaux mixture when the shoots are from six to eight inches the Department of Agriculture said today.