Andrea Bohata

Legumes are indispensable crops in sustainable agricultural systems because of their capability for biological nitrogen fixation owing to symbiosis with rhizobia and soil fertility restoration. Fungal pathogens from the genera Fusarium cause rotting and wilting and produce mycotoxins in plant tissues. The use of fungicides in sustainable agricultural systems is limited; therefore, the application of biological agents with antifungal activity against Fusarium spp. is desirable. Lactic acid bacteria (LAB) are promising control agents that produce a wide spectrum of functional metabolites. Lactiplantibacillus plantarum and other lactobacilli are the most intensively studied genera of LAB in relation to antifungal activity against Fusarium spp. However, LAB strains belonging to the lactobacilli and lactococci genera have not yet been isolated and characterised from legumes. Therefore, we aimed to obtain wild strains of LAB from legumes, screen them for functional characteristics with respect to their antifungal activity, and compare their antifungal activity against isolates of Fusarium spp. from legumes. Consequently, 31 LAB isolates belonging to 10 species were obtained and identified from legumes. Their functional properties, including genetics and proteomics, short-chain organic acid production, and antifungal activity against five Fusarium spp., of Lactiplantibacillus plantarum, Lacticaseibacillus paracasei, and Lactiplantibacillus pentosus isolates, were studied. Cell-free supernatants of L. plantarum and L. pentosus showed significant suppression of mycelial growth and conidial germination.

BACKGROUND Sweet potato whitefly ( Bemisia tabaci ) is one of the most destructive pests to an extensive range of crops and vegetables. Pesticide‐dependent management programs have led to severe health problems, including pesticide poisoning and cancer in human beings, as well as pesticide resistance in insect pests. Entomopathogenic fungi (EPF) are considered safe and highly effective against many pests. Therefore, identifying the pathogenicity and virulence of EPFs against Bemisia tabaci is a valuable addition to the management of their infestations. In this study, we investigated the efficacy of conidia suspensions of Aschersonia aleyrodis , Isaria fumosorosea , Beauveria bassiana , and Akanthomyces muscarius (= Lecanicillium muscarium ) against nymphal stages of Bemisia tabaci in cucumber seedlings under both optimal and suboptimal conditions. RESULTS All of the EPFs demonstrated significant ovicidal effects, with the highest cumulative mortalities observed in Aschersonia aleyrodis (96.46%) and I. fumosorosea ‐treated (94.60%) seedlings against host eggs and crawlers. Similarly, in the L4‐instars experiment, Aschersonia aleyrodis and I. fumosorosea were the most efficient, resulting in cumulative mortalities of 94.82% and 94.75%, respectively. However, Bemisia tabaci cumulative mortalities on seedlings treated with Akanthomyces muscarius (78.36%) and Beauveria bassiana (85.90%) were also significantly different from untreated seedlings (7.10%). Under suboptimal relative humidity (RH) conditions (≤ 45% RH), Aschersonia aleyrodis exhibited greater tolerance to harsh conditions, causing a significantly higher infection rate in L1–L2 nymphs (~92%) compared to the approximately 32% infected young nymphs observed in I. fumosorosea ‐treated seedlings. CONCLUSION All the selected EPF were more effective against the young nymphal instars. Our results also highlight the efficacy of Aschersonia aleyrodis under suboptimal conditions. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.