Plant Pathology Section

Cotton diseases are taking a toll of the crop every year in Pakistan. The major diseases of this crop in Pakistan are bacterial blight incited by Xanthomonas campestris pv. malvacearum, boll rot caused by various primary and secondary pathogens and root rot caused by Rhizoctonia solani while minor diseases enlisted in this country area seedling rot (various pathogens associated with seed or already present in the soil), anthracnose Collectotrichum capsici and C. gossypii), stunting (cause yet not known), leaf curl (virus transmitted by whiteflies), alternaria leaf spot (Alternaria macrospera and other species), cercospora leaf spot (Cercospera gossypina), myrothecium leaf spot (Myrothecium roridum), choanephora wet rot (Choanephora cucurbitarum) and the diseases caused by nematodes.

The losses caused by certain diseases are very obvious, as in case of root rot where the plants are killed outrightly while in others the losses caused are not evident and hard to quantify at various stages of plant development. In case of bacterial blight, the lesions developed on the leaves will cause a certain amount of loss by defoliation and on the stem and branches, by killing the fruiting branches and weakening the plant. This disease on the bolls will cause partial or full loss of the bolls attacked in addition to staining of lint and deterioration of cotton seed.

Usually a single control measure is not completely effective to control any disease and an integrated approach is more helpful. Certain practices which contribute to control one disease usually help in controlling others as well. In addition to chemical control, planting disease free seed, sowing resistant varieties, following crop rotation, destruction of the infected plant debris and many other practices should be included in plant disease control strategy.

Bacterial Blight:

Seedling rot and seed treatment of cotton:

Boll Rot:

Root rot:



Myrothecium leaf spot:

Cercospora leaf spot:

Cotton Leaf Curl:

Cotton nematodes:

Sooty mould: