Search

We investigated the anti-phytopathogen potential of silver nanoparticles synthesized by the bioreduction of AgNO3in Bacillus subtilisculture supernatant against Cercospora canescens, causing leaf spot disease in Vigna radiata(mungbean). The biosynthesized AgNPs were characterized using UV–visible spectroscopy that showed a broad Surface Plasmon resonance (SPR) peak at 410 nm, dynamic light scattering (DLS) measurement for size distribution and intensity, polydispersity index, and zeta potential for determining their stability. Atomic Force Microscopy determined that they were spherical with an average particle size of 8 nm. In vitro study and tripartite assay under greenhouse conditions were carried out to evaluate the nanoparticles application as a management strategy to control and/ protection from the Cercospora leaf spot disease in mungbean. The inhibitory effect of eight AgNPs concentrations was investigated for in vitro antifungal potential assessment; biosynthesized AgNPs were found to decrease the fungal growth and increase the mycelial inhibition. Their antagonistic effect was also recorded on conidial germination. The conidia under AgNPs exposure showed germination repression. The maximum mycelial inhibition (94.00 ± 0.5) was observed for 800 ppm at 96 h. The greenhouse experimentations revealed the antifungal efficiency of AgNPs against Cercospora Leaf spot disease in mungbean. The 800 ppm AgNPs concentration gave a statistically significant result (46.87 ± 3.74) and proved best in In plantaexperiment with maximum disease reduction. Cercospora leaf spot-induced biochemical alterations were recorded to be reversed towards normal levels after biosynthesized AgNPs application on challenged mungbean plants. Our data unravelled the potential of biosynthesized AgNPs against Cercospora canescenschallenge in mungbean, pointing towards its application in plant disease management.

Due to the potential use of amines as co-surfactants in microemulsions, the effect of adding alkylamines (C4–C8NH2) on the aggregation properties of cationic gemini surfactants [pentanediyl-1, 5-bis(dimethylcetylammonium bromide) and hexanediyl-1, 6-bis(dimethylcetylammonium bromide), referred to as 16-5-16 and 16-6-16 compounds] has been studied using tensiometry at 303 K. Data on critical micelle concentration (CMC), the surface properties C20(the surfactant concentration required to reduce the surface tension by 20 mN/m), ?max(maximum surface excess), Amin(minimum surface area per molecule) evaluated from the surface tension versus surfactant concentration plot, the interaction parameters ßs(for mixed monolayer formation at the aqueous solution/air interface), and ßm(for mixed micelle formation in aqueous medium) are reported. A synergistic interaction was observed both in the micelle as well as at interface, as evident from interaction parameters. Theoretical models of Clint, Rubingh and Rosen were used to explain and compare the results. More synergistic interaction was observed in 16-5-16 as compared to 16-6-16. The CMC values of 16-s-16 (s= 5, 6) decreased with increasing amine concentrations and the extent of the effect followed the sequence: octylamine > heptylamine > hexylamine > pentylamine > butylamine.