Blight/ Purple blotch

Blight/ Purple blotch
Blight/ Purple blotch:
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C. O. Alternaria porri (Ell.) Neergaard
A.palanderi Ayyangar

Symptoms:

• Small, whitish, sunken lesions appear on the succulent leaves
• Later, lesions enlarge, coalescing and cover large patches of leaves and to gridle the succulent leaf
• On severity infection spreads to the bulbs, resulting its decay
• Affected plants fail to flower
• Damage is considerable when the fungus is carried with the bulb to the storage

Management:

• Treat the seeds with Thiram or captan @ 3g/Kg seed before sawing
• Spray mancozeb @0.255 on the onset of disease and there after two sprays at an interval of 15 days.


Smut

Smut
Smut:
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C. O. Urocystis cepulae Frost

Symptoms:

• Fungus attacks the cotyledons of young plants soon after their emergence causing dark, elongated eruptive spots.
• On older leaves, lesions may extend from the base to the tip and appear as blisters
• Severely affected plants may be died in a month
• Blisters produce on the outer scales on the bulb
• Blister expose masses of black smut spores on rupturing

Management:

• Use resistant variety, avoid sawing of local susceptible variety.
• The disease can be controlled by seed treatment with Thiram @ 45 gm for 0.45 kg of seed