Field Resistance of Gossipium arboreum to Fusarium wilt

摘要

Fusarium wilt caused by Fusarium oxysporum f. vqsinfechm (A + K) Snyder and Han sen is an important disease of deshi cotton which was first observed in India at Nagpur by Evans in 1908. The disease usually occurs in patches which progressively increase in size are common and are said to be "wilt sick". The disease causes severe losses through the death of seedling and growing plants. Affected plant if survived shows stunted growth develop smaller bolls and immature lint, It was a major problem of diploid-cotton in the past and the damage caused by this disease used to go up to 60 per cent. At present also in North India the incidence has been recorded up to 60 per cent in Gossypium arboreum varieties in certain fields (Sheo Raj, 1992). Hence beforethe release of diploid cotton varieties and hybrids the testing for their resistance is pre-requisite.