Asian Journal of Microbiology and Biotechnology

Cotton (Gossypium spp.) is an important fibre crop, but its production is constrained by Fusarium wilt. The present study assessed the influence of sowing date on wilt incidence and evaluated selected botanical extracts and biocontrol agents against the pathogen under in vitro conditions. Field experiments were conducted at the Agricultural Field Research Centre, Hanumangarh, Rajasthan, during Kharif 2023–24 and 2024–25 in a randomised block design with three replications. Cotton was sown on five dates from 1 June to 29 June, and disease incidence was recorded at 15 days after first symptom appearance, 30 days after symptom appearance, and maturity. Early sowing reduced wilt incidence in both years. The 1 June sowing recorded the lowest mean disease incidence of 8.75%, 14.90%, and 23.30% at the respective stages, whereas the 29 June sowing recorded the highest mean incidence of 34.55%, 53.15%, and 74.00%. The inhibitory effect of six botanical extracts was tested at 2.5%, 5.0%, and 7.5% concentrations using the poisoned food technique. Neem showed the highest inhibition of mycelial growth, with 68.51%, 73.70%, and 79.63% inhibition at the respective concentrations, followed by tulsi with 64.44%, 70.37%, and 76.30% inhibition. Among the biocontrol agents, Trichoderma harzianum produced the highest inhibition of 85.19% at 5% culture filtrate concentration, followed by Trichoderma viride with 82.96% inhibition. The results indicate that early sowing, neem extract, and effective Trichoderma spp. may contribute to integrated management of Fusarium wilt in cotton.