Phytophthora Blight

  • Symptoms

  • Trigger

  • Biological Control

  • Chemical Control

  • Preventive Measures

Phytophthora Blight

Phytophthora drechsleri

Fungus


In a Nutshell

  • Water-soaked lesions on leaves.
  • Brown to black sunken lesions on stems and petioles.
  • Sudden death of infected plants.

Hosts

Red gram, Pigeonpea

Symptoms

Infected plants show water-soaked lesions on the leaves. On stems and petioles, brown to black and sunken-in lesions appear. Above the stems lesions the plant starts to wilt and can finally die. An infection of young seedlings leads to damping off (sudden death). If the plant does not die, large galls develop on the stem.

Trigger

Phytophthora Blight is a soil-borne fungus. It overwinters in plant debris. Humid conditions like drizzling rain and temperatures around 25°C favour an infection. Leaf wetness of 8h is required for an infection. Pigeon Peas develop a resistance to the disease after some time.

Biological Control

The infection risk can be reduced by applying potassium fertilizer.

Chemical Control

You can treat your seeds with 4 g metalaxyl per kg of seeds to prevent Phytophthora Blight.

Preventive Measures

Avoid water logging.,Sow plants on top of ridges.,Provide good drainage.,Apply crop rotation.