Phytophthara blight in Pigeon pea

    Phytophthora blight is a devastating disease that kills young plants. The disease occurs throughout India.

Etiology

            Causal organism : Phytophthora drechsleri f.sp. cajani

Disease cycle

            The disease is soil borne. The fungus survives as dormant mycelium in soil and in infected plant debris.

Symptoms

• Phytophthora blight resembles damping off disease as the seedlings die suddenly
•  Infected plants have water-soaked lesions on their leaves
• Brown to black, slightly sunken lesions on their stems and petioles
• Lesions girdle the main stems or branches which break at this point

               Brown to black sunken lesion on the stem                                       Complete drying of the plant

Epidemiology

 Cloudy weather and drizzling rain and temperature of 25⁰C  and leaf wetness of 8hrs favorable for disease development. Warm and humid weather following infection results in rapid disease development. Pigeon pea gradually develops tolerance to the disease as they grow older and not infected after they are 60 days.