Shoot rot and leaf fall (Phytophthora nicotianae)

Symptoms

• During the south west monsoon months of June -August, extensive leaf fall and shoot rot symptoms are observed.
• Black elongate lesions are first developed on the stem with exudation of gum.
• Later, infection spreads up and down, causing the tender stem to collapse and tender leaves to shrivel up.
• The lower mature leaves are also infected with black elongated lesions on mid rib, which later spread to the main lateral veins and the leaf blade. The infected leaves are soon shed.

Management

• Prune off the affected twigs well below the site of infection and destroy them.
• Protect the cut surfaces by spraying Bordeaux mixture (1 %).

Chemical Control

Extremely Toxic

Highly Toxic

Moderately Toxic

Slightly Toxic