Copper doped chitosan-guar gum nanocomposite: A multifunctional carrier for Trichoderma with potent antifungal...

In this study, a biopolymer-based nanocomposite was fabricated as a delivery material for the biocontrol agent Trichoderma harzianum Th4d. Cu-Cts-gg nanocomposite was synthesized using sol-gel method. Characterization studies like UV-vis spectroscopy, DLS, SEM and TEM were conducted to determine the nano size and shape of the nanocomposite. TEM analysis confirmed the formation of spherical shaped particles with an average size of 28.59 ± 4.23 nm. Entrapment of Th4d spores with the nanocomposite matrix exhibited entrapment efficiency of 99.75 to 100 %. Cu-Cts-gg-Th4d (1 % w/v) nanocomposite showed significant antifungal activity against soil borne pathogen Sclerotium rolfsii under both in vitro (100 % inhibition of mycelial growth) and in vivo (92.27 % disease reduction) conditions. Apart from this, Cu-Cts-gg-Th4d seed coating significantly enhanced the germination percentage, seedling vigour, fresh weight, and dry weight of groundnut plants. Root colonization and shelf-life studies of Cu-Cts-gg-Th4d proven its ability to deliver the Trichoderma to the target site, and to maintain the viability of Trichoderma up to 6 months under room temperature. It can be concluded that, Cu-Cts-gg-Th4d nanocomposite as a seed coating material is a promising alternative to the synthetic chemicals to provide seed protection against soil borne pathogens.