1. Leaf disease symptoms
(i) Greenish-grey spots are seen on the tips and edges of the leaves. The spots are round or uneven in shape.
(ii) The spots are large, light brown in color and eventually turn reddish black or blackish brown.
(iii) Rotting occurs with dark wet spots on the leaves.
(iv) A velvety coating is formed on the affected area.
(v) Root mycelium and conidiophores are seen on the underside of leaves.
(vi) Spots spread to petioles or petioles.
(vii) Diseased leaves become scorched.
(viii) Dry rot in tubers.
2. Stem disease symptoms
(i) In cloudy and humid weather the spots spread from leaves to stems and the plant droops.
(ii) At 12-250 C, the spots spread throughout the plant body.
(iii) If the attack is severe, the infected plant gives off a bad smell like rotten eggs.
(iv) Diseased plants die and turn black.
3. Disease symptoms in potato
(i) Reddish-brown spots appear on diseased potatoes or tubers.
(ii) Reddish brown black spots are seen on the skin of diseased potato.
(iii) Tuber moist rot.
(iv) Dry rot in tubers.
(v) Potato or tuber yield is reduced.