Journal of Advances in Biology & Biotechnology

Cotton anthracnose caused by Colletotrichum gossypii is a serious disease affecting cotton, an economically important fibre crop, resulting in substantial losses in terms of quality and yield. The present study was conducted to assess the effectiveness of nine new-generation fungicides for managing C. gossypii under in vitro and field conditions. In vitro evaluation showed that there were significant differences among the fungicides with respect to suppression of mycelial growth, conidial germination and sporulation of Colletotrichum gossypii. Gloit 300 EC (Propiconazole 13.9% + Difenoconazole 13.9% EC) produced the highest mean inhibition of mycelial growth (95.20%) and germination of conidia (93.66%) across the tested concentrations of 0.05, 0.10, 0.15 and 0.20%. Propiconazole 25 EC and Difenoconazole 25 EC followed this treatment, whereas Azoxystrobin 25 SC had the lowest inhibitory impact on the growth of mycelia and spore germination. Marked differences among fungicides were also observed in the suppression of sporulation. The fungicides were also tested in the field for control of cotton anthracnose, boll rot and leaf spot. Gloit 300 EC and Propiconazole 25 EC applied as foliar sprays at 0.1% significantly reduced disease severity and increased seed cotton yield, with the maximum yield (1328 kg ha⁻¹) recorded in plots treated with Gloit 300 EC. The study indicates that triazole-based fungicides, particularly the combination of Propiconazole and Difenoconazole, were effective in managing cotton anthracnose and associated foliar diseases under field conditions.