Chitosan and β-Cyclodextrin-epichlorohydrin Polymer Composite Film as a Plant Healthcare Material for Carbendazim-Controlled Release to Protect Rape against Sclerotinia sclerotiorum (Lib.) de Bary

The influence of beta-cyclodextrin-epichlorohydrin (beta-CD-EP) polymers on the improvement of the solubility and antifungal activity of carbendazim has been investigated. Meanwhile, the potential of the chitosan and beta-CD-EP composite film used as a plant healthcare material for carbendazim-controlled release to protect rape against Sclerotinia sclerotiorum (Lib.) de Bary has been evaluated. beta-CD-EP-1 and 2 (beta-CD content, 750 mg/g and 440 mg/g, respectively) were found to significantly improve the solubility of the guest molecule carbendazim (17.9 and 18.5 times, respectively) and the 1: 1 stoichiometry of the host-guest was confirmed by the Job's plot. A slight synergism was observed for the beta-CD-EP/carbendazim complex against S. sclerotiorum (Lib.) de Bary, indicating an enhancement to the bioavailability of carbendazim. The in vitro release studies revealed that beta-CD-EP polymers could efficiently modulate carbendazim release behaviors, such as the release retard and rate. The in vivo efficacy experiments demonstrated that the beta-CD-EP/carbendazim and chitosan composite film could significantly prolong the effective duration of carbendazim at a concentration of 100 mu g/mL compared with spraying carbendazim at 500 mu g/mL. Thereby, a highly useful and strategic concept in plant disease control by a plant healthcare material-the chitosan and polymeric beta-CD-EP composite film-is provided, which could also serve as a concept for related plant diseases.