• Wilting is the initial symptom.
• Yellowish brown coloured Sclerotia appeared on the infected tuber.
• Rotting of the tuber.
• Milky white and floccose appearance of the tuber.

Identification of pathogen:

Mode of spread and survival:

• The mycelium and sclerotia of the organisam subsist in the soil and are responsible for the infection of the crop.
• The pathogen is disseminated with infected soil, in running water and on farm implements.
• Mycelium and sclerotia may also be carried to soil with the seed tubers.
• In dry soil scleritia can remain viable for more than two years.

Epidemiology:

• Optimum temperature 30-35ºC.
• Alternate period of wet and dry soil condition.

• Treating seeds with mercury compounds after harvest reduces tuber rot.
• Treating the furrows at planting with PCNB @ 15kg/ ha reduces the disease incidence.
• The disease is low in the variety Kufri Sindhuri.
• Among the Indian commercial cultivars, Kufri Bahar, Kufri Chamatkar, Kufri Jyothi, Kufri muthu and Kufri swarna are resistant.
• The disease can be controlled to a certain extent by growing non susceptible crops like corn and sorghum.