Tomato Plant Pests and Diseases



Tomato Plant Pests and Diseases

Verticillium Wilt

Tomato Verticillium Wilt This is a tomato plant trouble — known as Sleepy Disease — which results in severe wilting and yellowing of the plant. It is usually caused by the fungus Verticillium alboatrum which attacks the roots and base of the plant and eventually poisons the sap. Although its effects are very similar to those produced by root-rot it can be identified by the fact that in sleepy disease the wilting normally affects the lower leaves first, whereas with root-rot the wilting usually starts at the top of the plant.

Another difference is that, unlike root-rot, this trouble is most apparent in cool air and soil conditions. Internal discolouration of the stem, which with root-rot seldom affects more than the lower few inches, may extend to the top of the plant.


Tomato Blossom End Rot

This is a physiological disorder of tomato plants which becomes visible as a dark flattish area on the apex of the fruit, although it is present on the inside of the fruit before then. It occurs chiefly on the first-formed fruits and is caused by insufficient water reaching them. Vigorous tomato plants with large, soft foliage are the most liable to be attacked as on such plants the leaves tend to absorb moisture which should be going to the fruits. The best method of preventing the trouble is to aim at well-balanced growth with a good root system which can take up sufficient water for both leaves and fruit.


Tomato Blotchy Ripening

This is the term given to a condition of tomato plants in which instead of the fruit ripening to an even red colour they become blotched with yellow or orange. It may be due to potash deficiency and then may often be corrected by two or three dressings of sulphate of potash, applied at up to 2oz. per square yard. The best thing, however, is to make sure of a balanced fertiliser treatment before planting, and to aim at a good root system, together with adequate soil moisture, so that the plant can take up the necessary potash. Blotchy ripening may also occur when fruits are unduly exposed to the hot rays of the sun under glass.


Tomato Leafmould

This fungal disease causes much trouble on tomato plants grown under glass. Pale yellow spots appear on the upper surface of the leaves and a brownish-grey mould on the under surface. It spreads rapidly in hot, moist conditions and the leaves may wither completely. Ventilation and effective air circulation are important counter measures and affected leaves should be removed. Control with a zineb spray.

01. December 2010 by Dave Pinkney
Categories: Fruit & Veg, Salads | Tags: | Comments Off on Tomato Plant Pests and Diseases

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