REACTIONS OF SOME COTTON VARIETIES (GOSSYPIUM HIRSUTUM L.) AGAINST SEEDLING DISEASE IN TURKEY

The aim of study was to determine the reactions of some cotton varieties (Gossypium hirsutum L.) registered in Turkey against seedling root rot pathogens in-vivo. Twenty varieties were tested to determine reactions against Rhizoctonia solani, Fusarium spp. and R. solani+Fusarium spp. in the growth chamber. A pot trial was carried out in a randomized plot design with four replications. The emergence (E), pre-emergence damping-off (PrE), post-emergence damping-off (PsE) and hypocotyl disease index (HDI) values of the fungicide (F) and non-fungicide (NF) treated cotton varieties were determined in the experiment. The highest E against R. solani and Fusarium spp. was found Stoneville468 and Pg2018 (90%), Sezener76 and ipek607 (90%) in the NF; Gaia (100%), Ba440 (97.50%), Julia and Adn712 (97.50%) in the F respectively. The lowest PrE against R. solani was determined Stoneville468 and Pg2018 (%10) in the NF; Gaia (0%) and Ba440 (2.50%) in the F. The lowest PsE against R. solani and R. solani+Fusarium spp. was detected Acala Royale (52.46%;54.17%) and Gaia (52.78%) in the NF; Acala Royale (39.44%;37.78%) in the F respectively. The lowest HDI value against R. solani and R. solani+Fusarium spp. was found Acala Royale (1.67;1.74) in the NF; Acala Royale (1.55;1.54), Gaia and Adn712 (1.65), Stoneville468 and Julia (1.71) in the F respectively. The lowest PrE against Fusarium spp. was determined Sezener76, Ipek607, Acala Royale (10%); the lowest PsE against Fusarium spp. was determined Acala Royale (54.48%) in the NF respectively. The lowest HDI value against Fusarium spp. was found Acala Royale (1.78) in the NF. As a conclusion, Gaia and Stoneville468, Sezener76, ipek607 and Acala Royale were the first to precipitate in the PrE and PsE and HDI to R. solani and Fusarium spp. Acala Royale and Stoneville468 were predominant in the PsE and HDI against R. solani+Fusarium spp.