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The current investigation assessed the effectiveness of 30 citrus germplasms in combating citrus canker pathogenesis in Assam, North‐East India. Significant differences were observed among the examined citrus germplasms in terms of per cent disease severity and disease reduction against Xanthomonas citri pv. citri. Among the 30 different germplasms, eight germplasms, namely, Jora tenga (14.67%), Bonjora (15.58%), Holong tenga (15.75%), Latipes (17.34%), Patijora (17.75%), Birajora (18.50%), Cleopatra mandarin (20.00%) and Ada jamir (20.18%), exhibited highest disease resistance potential. The study recorded that the germplasm Latipes, which are resistant, had the highest total phenol content (21.26 mg/g dry weight), while the susceptible one, Grapefruit (7.85 mg/g dry weight), had the lowest total phenol content. Jora tenga exhibited the highest flavonoid content, measuring at 6.48 mg/g dry weight, whereas White pummelo had the lowest flavonoid content, measuring at 1.88 mg/g dry weight. Similarly, the highest alkaloid percentage was recorded in resistant germplasm, Adajamir (10.52%), while the lowest was in susceptible germplasm, Volkameriana (2.30%). The levels of total phenol, alkaloid and flavonoid contents exhibited a significant negative correlation with the per cent disease severity of citrus canker disease in both Pearson correlation and Spearmen correlation analysis. The current research on bioprospecting of citrus germplasms in relation to citrus canker pathogenesis has the potential to offer valuable insights into mitigating the transmission of bacterial pathogens and eliminating sources of infection by employing resistant cultivars and implementing approved doses of plant protection formulations. [ABSTRACT FROM AUTHOR]

In-vitro studies were conducted to check the compatibility of microbial bioagent, Trichoderma viride with seven fungicides, eigtht insecticides, two herbicides, three fertilizers, and two antibiotics at different concentrations. The bioagent was compatible with insecticides viz., imidacloprid 27.8% SL, diafenthiuron 50% WP, chlorantraniliprole 18.5% SC, flubendiamide 20% WG, azoxystrobin 23% SC, deltamethrin 2.8% EC, clothianidin 50% WDG, fenpropathrin 10% EC, and tiamethoxam 25% WG at all the four concentrations. However, fungicides hexaconazole 5% EC, propiconazole 25% EC, tebuconazole 25.9 % EC, and tebuconazole 50% + trifloxistrobin 25% WG and copper oxychloride 50% WP showed incompatibility with T. viride. Among the herbicides, glyphosate 41% SL was compatible, while paraquat dichloride 24% SL showed an incompatible reaction. Urea and muriate of potash (MOP) showed varied compatibility at different concentrations, while single super phosphate (SSP) showed a compatible reaction with the microbial bioagent. The results also indicate that antibiotic like streptomycin and gentamycin are compatible with T. viride. Knowledge of the compatibility of the microbes and the agrochemicals will be useful to apply biopesticide formulations in combination with inorganic pesticides, targeting different pests to reduce the cost and time. [ABSTRACT FROM AUTHOR]

Fruit rot is one of the most destructive diseases of Capsicum chinense Jacq., popularly known as Bhoot jolokia or King Chilli an export oriented crop in North East India. Morpho-cultural characterization of the isolated fungal pathogen from diseased fruit identified the pathogen as Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. Pathogenicity test further confirmed its association with the disease. A few bacterial and fungal microbial biocontrol agents (MBCAs) were screened in vitro against C. gloeosporioides as a potential solution in organic and integrated crop management practices. Among all the MBCAs Bacillus subtilis LB22 showed highest inhibition (85.00%) on mycelial growth of the pathogen followed by P. fluorescens (84.33%) and B. vallismortis (83.22%). Trichoderma pseudokoningii were recorded the lowest inhibition (53.22%). Our study put forth further exploration B. subtilis LB22 (NCBI accession no. ON386193 and NBAIM accession no. NAIMCC-B-03226) in planta and their response in disease suppression as well growth promotion in Bhut jolokia as a component of sustainable crop health management program. [ABSTRACT FROM AUTHOR]