PATH 372 Diseases of Horticultural Crops

Infection restricts flowering and fruits are not formed, if formed, turns smaller,
harder and rough. Loss in fruit yield ranges from 50-100% based on disease
incidence
Disease cycle
P.I: Infected plant parts
S.I: The virus is transmitted by the whitefly, Bemisia tabaci.
Management
Tolerant varieties: Parbhani Kranti, Pusa savani, Janardhan, Haritha, Arka
Anamika and Arka Abhay
The disease spread can be restricted by spraying Monocrotophos, 1.5 ml/l.
2) Cercospora leaf spot: Cercospora malayensis, C. abelmoschi
C. malayensis causes brown, irregular spots and C. abelmoschi causes sooty
black, angular spots on lower surface of leaves
Both the leaf spots cause severe defoliation and are common during humid season.
Disease cycle
P.I: The fungi survive through conidia and stromata on crop refuse in soil.
S.I: Air borne conidia
Management
Spray mancozeb or zineb@0.2% or carbendazim@0.1% for disease control a
month after sowing and repeat at fortnightly intervals based on disease incidence.
3) Powdery mildew: Erysiphe cichoracearum
Symptoms
Grayish powdery growth occurs on the under as well as on the upper surface of the
leaf causing severe reduction in fruit yield.
Management
Dust finely ground sulphur at 30 kg/ha or spray wettable sulphur@0.3% or
Dinocap@0.1% , three to four times at 15 days intervals.
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