Post-harvest tuber rots: Sclerotium rolfsii
- 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 organism 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.
- 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.