Irradiated Silver Nanoparticles Synthesized by Plant Extract and Their Effect on Early Blight Disease of Tomato (Lycopersicon esculentum Mill.)

Nanoparticles of silver (AgNPs) were prepared by the green synthesis method using neem ( Azadirachta indica ) and lemon leaf extract. AgNPs were irradiated with several doses of gamma irradiation: 0, 1.5, 3, 6, 12, and 24 kGy. AgNPs were tested in the field against Alternaria solani , a tomato disease that causes early blight. There was a notable rise in various growth and physiological measurements. Every aspect of the plant's performance, including physiological traits and crop yield, showed an improvement. FT-IR, TEM, UV-Vis, and DLS are used to characterize AgNPs. The results were computed as an average of two seasons. Application of neem AgNPs under 6 kGy and lemon AgNPs under 12 kGy were used as foliar spraying. A highly effective inhibitor of disease severity was obtained after mancozeb as compared with control (untreated). The improvement of all aspects of the plant was observed as well as yield, compared with the control (untreated). The results also showed that there were significant differences in enzymes activity compared with the infected control (untreated). The highest value of peroxidase activity occurred with neem AgNPs under 3 kGy (39). The highest value of catalase was obtained by combining lemon AgNPs with 6 kGy (31). The highest value of polyphenol oxidase was achieved by neem AgNPs under 1.5 kGy (35). All treatments were evaluated for total chlorophyll content in comparison to the control treatment, with the healthy plant achieving the highest value (26), followed by the neem AgNPs under 6 kGy, which recorded 23.1.