Efficacy of different fungicides against Fusarium wilt of cotton caused by Fusarium oxysporum f. sp Vasinfectum

Fusarium oxysporum f. sp. vasinfectum (Atk.) Snyd. & Hans was isolated from wilted cotton plants collected from Shahdad Pur and Tando Jam. Pathogenicity test of Fusarium oxysporum f. sp. vasinfectum was conducted on four cotton varieties viz, Cris-9, TH-41/83. CIM-448 and Shahbaz-95. The growth of artificially inoculated plants of Cris-9 and TH-41/83 significantly reduced and plants were completely dried after 20 days of inoculation. The numbers of germinated plants were also lower as compared to Shahbaz-95 and CIM-448. Carbendazim at its three doses significantly inhibited the mycelial growth of the fungus followed by Thiophanate methyl and Dithane M-45. There was not significant difference in mycelial growth of the fungus on Thiovit (35.75 mm) and control (37.87 mm) in which fungicide was not used. The maximum root and shoot length of cotton varieties was recorded with Carbendazim followed by Thiophanate methyl, The growth was significantly increased in Shahbaz-95 and CIM-448 as compared to Cris-9 and TH-41/83 varieties. Carbendazim also significantly reduced the colonization of Fusarium oxysporum f. sp. vasinfectum on root pieces of Cris-9 variety. The growth of Cris-9 also increased when plants were inoculated with low level of inoculum (10.75cm and 12.25cm) than at high inoculum levels (6.72cm and 5.85cm).