Submitted by Spicepedia
The disease appears usually in the nursery where seeds germinate (primary nursery) during rainy season when there is excessive soil moisture due to improper drainage. Prolonged dampness is conducive for disease development.
The disease is caused by soil borne fungi such as Pythium vexans and Rhizoctonia solani. Fusarium oxysporum also causes similar seedling rot.
Leaves turn pale yellow, followed by rotting of the collar portion of seedlings. As infection advances the young tillers fall off. The infected seedlings die and collapse in masses.
In primary nurseries, thin sowing may be practiced to avoid overcrowding of seedlings. Adequate drainage facilities may be provided to prevent water stagnation. Maintain proper phytosanitary measures in the nurseries by removing infected and dead seedlings. When the initial symptoms are noticed, drench nursery beds with 0.2 % copper oxychloride (COC) @ 3-5 litres/ m2. Two to three rounds of drenching may be adopted at an interval of 15 days. Pre treatment of seeds with Trichoderma or Pseudomonas before sowing reduces the chance of early incidence of the disease in nurseries. Further, application of Trichoderma to the nursery bed @ 100 g/m2 reduces subsequent disease spread.