Alternaria leaf blight
Caused by: Alternaria dauciProblem Category: Fungal Disease
Symptoms: Green-brown water-soaked lesions on leaves which enlarge and turn dark brown or black; lesions may coalesce causing leaves to yellow and die; lesions may be present on petioles
Comments: Disease emergence favored by wet foliage and warm weather; rain and fog enhance the development of the disease; fungus survives in soil on crop debris but is killed when the debris decomposes
Management: Disease can be difficult to control in wet, warm conditions; apply appropriate fungicides when first symptoms appear or as a protective measure in humid areas; treat seeds with fungicide or hot water prior to planting; apply gibberellic acid to carrot foliage to promote upright growth and promote air circulation through canopy
Control: spray 2 times 10% Cowdung+Asafoetida solution in 10 days interval.