Biological efficacy of chitosan nanoparticles and black poplar buds ethanolic extract against potato dry rot

The purpose of the recent study was to evaluate the effectiveness of chitosan nanoparticles (CSNP) and black poplar buds extract (BpE) to protect potato tubers from post-harvest Fusarium dry rot. A high virulent Fusarium isolate was recovered from natural infected tubers in Astrakhan region and subjected to molecular identification using ITS rDNA gene and identified as Fusarium sumbucinum . CSNP were successfully prepared by ionic gelation method with size ranged from 79.4 to 186.4 nm as observed by scanning electron microscopy (SEM), and a positive zeta potential of 53.1 mv. CSNP at a concentration of 2 g/l, and BpE at a concentration of 40 g/l completely inhibited Fusarium fungal growth on PDA medium in vitro . CSNP at a rate of 20 g/t and BpE at a rate of 400 g/t significantly reduced the incidence of dry rot under natural infection during 8 months of storage by 54.7 and 58.5% and reduced the disease index by 65.7 and 72.3%, respectively, and there was not a significant difference between the two treatments. These results demonstrate the potential of CSNP and BpE for protection of potato tubers against the fungal postharvest decay.