RESUMO
The use of chitosan as an alternative for fungicides has received more attention worldwide. Hence, this study aimed to evaluate in vitro and in vivo antifungal activity of chitosan against Fusarium solani causing root rot in fenugreek. Chitosan treatments ranged from 0.1 to 2gL-1 were tested against F. solani on to potato dextrose agar and in potato dextrose broth. The results revealed that increase in concentrations of chitosan significantly reduced growth, dried biomass, sporulation and spore germination of F. solani. The hyphal swellings and distortion of F. solani mycelia were induced by chitosan. Fenugreek seeds treated with chitosan at 2 gL-1 and 0.5 gL-1 showed reduced F. solani infection and increased seed germination, respectively. In pot and field studies, fenugreek seeds treated with chitosan at 2.0 gL-1 greatly reduced root rot disease severity and also enhanced yield parameters. The activity of defence enzymes, such as chitinase, ß-1, 3-glucanase and total phenol were increased in chitosan treated in fenugreek plants. This increased activity offered protection to fenugreek plants against F. solani to a greater extent. The results showed that chitosan could be used as inducer of defense response and has the potential of controlling fenugreek root rot disease.
