Growing Food: A Guide to Food Production

from pests by interplanting them in various configurations with protective

( companion ) plants such as onions, garlic and marigolds.

Diseases: Blight can be just as big a problem with tomatoes as with potatoes.

Controlled with two-weekly sprays of Bordeaux mixture (copper sulphate).

Bacterial Wilt makes plants wilt very rapidly, without yellowing, and die; worse in

the wet tropics and in waterlogged soil.

Fusarium Wilt. The plants wilt, the leaves become yellow. The symptoms of

Sclerotium Wilt are that plants wilt rapidly, and feathery white growths appear on

the stem, mainly at ground level.

Verticilium Wilt (“sleepy disease”) is caused by a fungus which attacks the roots

and base of the stem, especially in cold wet soil. Earthing up larger plants with good

soil may save them, as new roots may be formed above the infection; otherwise the

plants droop and die.

Septoria Leaf Spot causes brown water-soaked spots to appear on the leaves, which

may then fall off.

Grey Leaf Spot may cause complete defoliation.

Virus Diseases include Tobacco Mosaic, Spotted Wilt, Cucumber Mosaic, Curly

Top and Tomato Yellow Top—all spread by aphids and handling, and may originate

in nearby plants of other Solanaceae plants, or cucumbers. Some virus disease may

even originate in tobacco, so cigarette smokers may transmit this disease to the

tomato plants while working with them.

Blossom End Rot occurs on the young fruit when vigorously growing plants are

stressed, by either too much or too little water, or when the roots are damaged. The

tip of the fruit dies and turns dark brown; the whole fruit may become infected.

Greenback causes fruit to remain green and unripe on the base around the stalk;

unripe area appears hard. This disease develops most rapidly in strong sunlight, and

is associated with potash deficiency. Susceptibility to Greenback varies according to

the variety.

YIELD

The global average yield of tomatoes grown on a field scale is about 10 MT/ha.

More than 25 MT/ha is produced in more sophisticated systems.

UTILISATION

• rich in Vitamins A, C and others as well as certain minerals, particularly

•

•

potassium (250 mg/100 g). Carbohydrate content (fructose and glucose) is about

242 TONY WINCH

The ripe fruit of tomatoes is eaten raw or cooked. It is about 90% water, but is

3% and there is very little fat or protein.

The green fruit is used in pickles and preserves.

Tomatoes are processed into soup, juice, sauce, ketchup, purée, paste and

powder. There is also a very large tomato canning industry.

be controlled by introducing their natural predators. Tomatoes are often protected

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