PATH 372 Diseases of Horticultural Crops
PATH 372 Diseases of Horticultural Crops
PATH 372 Diseases of Horticultural Crops
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3) Choanephora blight /Wet Rot (Choanephora cucurbitarum)<br />
Symptoms:<br />
The pathogen attacks flowers, buds and tender young shoots.<br />
This disease produces a blossom blight as well as a fruit rot stage and occasionally<br />
a leaf blight.<br />
Blossoms exhibit a lack <strong>of</strong> turgidity as petals begin to wilt.<br />
Luxuriant growth <strong>of</strong> the pathogen is seen on infected portion which appears as<br />
black pin heads or Stiff whisker-like strands <strong>of</strong> the causal fungus, topped with<br />
black heads (sporangia) grow <strong>of</strong>f the infected blossoms causing a blossom drop.<br />
Young fruit may become infected, s<strong>of</strong>ten and abort with the black fungal growth<br />
apparent on the fruit.<br />
Management:<br />
A dopt recommended spacing to maintain adequate air circulation.<br />
Select the seeds from healthy fruits and treat the seed with captan or<br />
thiram@3g/kg seed<br />
Spray Mancozeb@0.25% or Copper oxy chloride@0.3%<br />
Grow resistant varieties like Seoul hot, Liachi-2, AT-Good, etc.<br />
4) Mosaic complex<br />
Chilli mosaic virus, Potato Virus Y, Cucumber Mosaic Virus (CMV), Tobacco<br />
Mosaic Virus (TMV) and Tomato spotted wilt virus<br />
Symptoms: Symptoms vary with the infected virus<br />
TMV:<br />
• Backward bending <strong>of</strong> petiole<br />
• Raised blisters and mottled areas <strong>of</strong> light and dark green areas on the foliage<br />
• Leaves point towards ground.<br />
• Necrotic spots on stem.<br />
• Fruit ripens unevenly and is reduced in size<br />
CMV<br />
• Downward curling along with midrib<br />
• Most plants exhibit some degree <strong>of</strong> "shoestringing" (narrowing <strong>of</strong> the leaves) in<br />
addition to stunting, yellowing, and whitish spotting <strong>of</strong> the leaves.<br />
• Fruit may be small and distorted.<br />
PVY<br />
• Vein banding<br />
• Small, crinkled leaves.<br />
Spread<br />
Sap transmissible (TMV)<br />
Aphids: Myzus persicae, Aphis gossypii, A. craccivora<br />
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