Chitosan for Plant Growth Promotion and Disease Suppression against Anthracnose in Chilli

Chitosan is naturally occurring compound potentially used in sustainable agriculture to control plant diseases and enhance growth. An attempt was made to control anthracnose or ripen fruit rot of chilli caused by Colletotrichum capsici in the field under inoculated condition and to increase the growth and yield of chilli by different concentrations of chitosan as seed treatment and foliar application methods. C. capsici isolate “So” was found to be the most virulent against chilli at the time of pathogenicity test. Chitosan at 1% concentration was found to be most effective against the radial growth of C. capsici. Subsequently, seed treatment or foliar spray was done with C. capsici spore suspension (5×106 ml-1) and different concentrations of chitosan as per requirement of the treatments. Anthracnose or ripen fruit rot of chilli and post-harvest disease incidence (DI) and percent disease index (PDI) were significantly lowest in the treatment T8, where seeds were treated with 1% chitosan combination with foliar spray of chitosan (0.5%) in pathogen inoculated condition. On the contrary, anthracnose or ripen fruit rot of chilli and post-harvest DI and PDI were significantly highest in the treatment T1, where seeds were treated with C. capsici. Germination percentage, growth promoting components, yield and thousand seed weight (TSW) were also highest in treatment T8 compared to all other treatments. As a result, the combined use of chitosan as seed treatment (1%) and foliar spray (0.5%) appeared to be most effective in controlling anthracnose of chilli and increased yield and yield contributing characters