Biodegradable Schiff bases: a novel approach for the management of pathogenic fungi (Sclerotium rolfsii and Rhizoctonia bataticola) and stored grain insect (Callosobruchus maculatus) in green gram (Vigna radiata).

ABSTRACT

Twenty-two eco-friendly, novel Schiff bases were synthesized from 2,4,5-trichloro aniline and characterized by using FT-IR, 1H NMR, and 13C NMR techniques. Fungicidal activity against pathogenic fungi Sclerotium rolfsii and Rhizoctonia bataticola and insecticidal activity against the stored grain insect pest Callosobruchus maculatus of the test compounds were evaluated under control condition. All of the investigated compounds, according to the study, exhibited moderate to good antifungal and insecticidal activities. The best antifungal activity against both pathogenic fungi was demonstrated by C15 and C16 whose ED50 values were recorded 11.4 and 10.4 µg/mL against R. bataticola and 10.6 and 11.9 µg/mL against S. rolfsii, respectively. They were further screened in for disease suppression against both pathogenic fungi under pot condition through different methods of applications in green gram (Vigna radiata L.) crop. The compounds C10 and C18 had the highest insecticidal activity, with LD50 values of 0.024 and 0.042 percentages, respectively. Stepwise regression analysis using root mean square error (RMSE) and correlation coefficient (R) method used to validate the quantitative structure activity relationship (QSAR) of synthesized compounds in addition to their fungicidal and insecticidal actions. To the best of our knowledge, this investigation on the 22 new Schiff bases as possible agrochemicals is the first one that has been fully reported.