Root rot caused by Macrophomina phaseolina (Tassi.) is a common soil-borne disease in black gram, and its management with chemicals showed persistent toxicity and soil degradation. The existing bioagents, such as talc formulation, lead to leaching and are less productive. Hence, developing liquid bioformulation is essential to contain the disease and maximize the yield. Therefore, the current study aims to investigate the efficacy and survivability of liquid formulation of Trichoderma asperellum (Tv1 LF), metabolites against root rot of black gram, and their growth promotion. The results showed that the vigor index 4025.00 with a spore load of 1X108 cfu/ml was recorded for growth promotion and spermophere study @ 5ml /kg of seeds with Tv1 LF. The treatment T8 significantly reduced the incidence (9.1%) against control (74.3%), with an increased biomass index in the glasshouse condition. There are 32 mVOCs profiled during the tri-trophic interaction in black gram roots, and they were up or down-regulated, Viz., Mollugin, Pentadecanoic acid, Cyclopropaneoctanoic acid 2-octyl-, methyl-ester, Rhodopin, Dodecanoic acid, 1,2,3-propanetriyl ester involved in pathways like jasmonic acid, glyconeogenic and act as acyl-CoA: acyltransferase-2 inhibitor. The results of this study confirmed that Tv1 LF performed better in growth promotion and managing root rot of black gram.

A study was under taken to isolate and screen selected beneficial microbes, which can restore soil fertility in the chosen flood-affected areas of Attapady and Nelliyampathy in Palakkad district of Kerala, India. A total of 76 isolates (40 N-fixers, 26 P-solubilizers and 10 K-solubilizers) were obtained from the flood affected areas. Triple enzyme activities of cellulase, laccase and dehydrogenase were recorded in 47.36% of N-fixers from Attapadi, 36.36% P-solubilizers and 60% K-solubilizers from Nelliyampathy. Six diverse maximal enzyme producers were selected based on study of microbial dry weight and plant growth-promoting characteristics, including nitrogen(N) fixation, phoshphate(P), potassium(K), and indole acetic acid(IAA) synthesis. These 6 isolates were ranked according to all the evaluated characteristics using statistical analysis, and the top 3 isolates were found. The most efficient multi-functional N-fixer was identified as Priestia megaterium from Attapadi which ranked first, Aspergillus terreus as the most capable P-solubilizer from Nelliyampathy and Talaromyces pinophilus as the most proficient K-solubilizer from Nelliyampathy. The competence of these three isolates from flood affected regions could help in the rejuvenation of the soil organic matter (SOM) in degraded soils. However further evaluation under field conditions are required to confirm these results.