Take care of
Potatoes are growing strongly now. In most places they have been
earthed up. Remember, when earthing, not to draw the soil up to a greater
height than about 6 in. and do not leave a flat top or trough to the ridge.
Finish it off to as sharp a point as possible. This prevents spores of
potato blight from being washed down by rain to infect the tubers. Don't try
to earth up when the soil is wet.
To a large extent the danger of blight attack depends on the
weather; if dry, only local attacks are likely and will not cause serious
damage; given frequent spells of warm, moist weather, the tops may be
completely killed by the end of July or in August. The effect on the crop
would be serious if the tops were badly affected. The weight of crop would
be greatly reduced; and if the disease spreads to the tubers themselves,
they may rot in the ground or after you have stored them.
WHAT TO DO. If you live within 10 or 12 miles of a large industrial
centre, where the air is laden with fumes and smoke, do not spray, but seek
advice locally: the secretary of your local allotment society, the
horticultural committee of the council or the park superintendent should be
able to help you. Gardeners who are not in areas likely to be affected by
fumes from factories should, as a form of insurance against blight, spray
their potato foliage...
ED NOTE: [a
formula for Bordeaux mixture was not included as it is illegal in several
countries to use the homemade fungicide - see
Home Mixing of Bluestone is Banned? - also see
Soil Association for more information on potato blight.]