Powdery mildew
1. Powdery mildew:
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C. O. Erysiphe cichoracearum Dc.

Symptoms:

• Grayish powdery growth on the lower as well as upper surface of the leaf
• Severer reduction in fruit yiels

Management:

• Effectively manage by wettable sulfur @ 0.2%. Three sprays, first at the onset of disease and there after interval of 15 days


Yellow vein mosaic/ Vein clearing
2. Yellow vein mosaic/ Vein clearing:
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Symptoms:

• Characterized by yellowing of the entire network of veins in the leaf blade
• On severity, the young leaves turn yellow , become reduced in size and the plant becomes stunted
• Flowering of the plant is restricted, the fruits, if formed are small, rough and harder than any stage of plant growth.
• Virus transmitted by white fly (Bemisia tabaci)

Management:

• Grow reseistant variety pusa savani
• Rouging out the diseased plant
• Periodical spraying of suitable insecticides to manage the white fly population.


Cercospora leaf spot

3. Cercospora leaf spot:
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Symptoms:

• Cercospora malayensis Solh and Sv. Causes brown, irregular spots
• Cercospora abelmoschi Ell. And Ev causes soty black, angular spots
• Both leaf spots cause severe defoliation and common during humid seasons

Management:

• Spray Copper oxychloride fungicide @ 0.25% or mancozeb @ 0.25%