Combination of different marine algal extracts as biostimulant and biofungicide

This study investigates the efficiency of seaweed liquid fertilizer (SLF) prepared from combinations of different seaweeds (Sargassum polyphyllum, Turbinaria ornata, Gelidiopsis sp., Padina tetrastomatica, Gracilaria corticata) as a stimulant for the growth of Vigna radiata (Mung) as well as its antagonistic activity against fungal pathogens (Alternaria solani, Rhizoctonia solani., Sarocladium oryzae). 100% SLF was prepared, which was further diluted to 60%, 40%, and 20%. Seeds were soaked in four different concentrations of the SLF (20%, 40%, 60%, and 100%) for 12hr and planted. After 60d, the root and shoot length were increased by 14% and 16%, respectively, with SLF (100%). The carbohydrate and protein concentrations were also increased by 70% and 86%, respectively, at 100% SLF. The concentration of chlorophyll a, chlorophyll b, and carotenoids were found to be increased by 20%, 43%, and 28%, respectively, with 100% SLF. Further, the SLF (60% and 100%) successfully inhibited the growth of fungal pathogen A. solani but the other tested strains were found to be resistant. The present study indicates that 100% SLF concentration acts as both biostimulant and biofungicide for A. solani and thus, this SLF could be used as a potential alternative to the chemical fertilizers.