pectins and carbendazim

This study aims to encapsulate the fungicide carbendazim using a biodegradable polymer (pectin). First, we have obtained calcium pectinate beads (CPG-Carb) by ionotropic gelation using calcium ions as a crosslinking agent. These beads were then coated with silica starting from tetraethoxysilane (TEOS), by a sol-gel process to form hybrid beads (CPG-Carb-SG). The morphology, composition and structure of both beads were characterized and the controlled release assays of the fungicide were studied in both water and soil columns. The encapsulation efficiency for CPG-Carb was slightly higher (75%) compared to CPG-Carb-SG (67%) due to carbendazim loss during the impregnation and condensation steps. The release rate in water and soil columns was about 4 times lower for CPG-Carb-SG than CPG-Carb demonstrating the efficiency of the silica coating to delay the release of carbendazim. Moreover, the release of CPG-Carb-SG is due to the erosion of the silica layer during the first two weeks. After this period, the silica layer was degraded, and the release is then controlled by the swelling of the organic part of the bead as observed for CPG-Carb. Finally, the biodegradability of the pectin, and the release profile make such systems promising candidates for sustained and economical pesticide delivery systems.

Topics: Benzimidazoles; Carbamates; Pectins; Silicon Dioxide; Soil; Water

Synthesis and controlled release study of polymeric nanoformulation of carbendazim (2-benzimidazole carbamic acid methyl ester) using chitosan and pectin is reported in this article. The formulation was subjected to morphological, physiological, in vitro fungicide release and bio-efficacy evaluation studies. The average size of nanoparticles was found to be in the range of 70-90 nm as confirmed by transmission electron microscopy. The in vitro fungicide release of nanoformulated carbendazim was compared with pure carbendazim at different pH values. The results confirmed sustained release of nanoformulated carbendazim. The bio-efficacy evaluation of the carbendazim nanoformulation was carried out against Fusarium oxysporum and Aspergillus parasiticus. The nanoformulation showed 100 % inhibition of test fungi at both concentrations (0.5 and 1.0 ppm) while pure carbendazim showed 80 ± 0 % and 97.2 ± 1.1 % inhibition at 0.5 and 1.0 ppm concentration respectively against Fusarium oxysporum and 86.0 ± 0.6 % inhibition and 100.0 % inhibition at 0.5 and 1.0 ppm concentration respectively against Aspergillus parasiticus. The commercial formulation (WP 50) showed 42 % and 58.0 ± 0.1 % inhibition at 0.5 and 1 ppm concentration respectively against Aspergillus parasiticus and 50.5 ± 0.7 % and 70.0 ± 0 % inhibition at 0.5 and 1.0 ppm concentrations respectively against Fusarium oxysporum. Phytotoxicity evaluation of nanoformulated fungicide confirmed that the nanoformulated carbendazim is safer for germination and root growth of the seeds of Cucumis sativa, Zea mays, and Lycopersicum esculantum.

Topics: Aspergillus; Benzimidazoles; Carbamates; Chitosan; Delayed-Action Preparations; Fungicides, Industrial; Fusarium; Nanoparticles; Pectins; Polymers