Zinc-functionalized thymol nanoemulsion for promoting soybean yield.

Herein, we report zinc-functionalized thymol nanoemulsion (Zn-TNE) by sonication method and its characterization by DLS, HR-TEM, FEG-SEM-EDS, Cryo-FESEM, FTIR and AAS studies. Zn-TNE treated seeds bestowed better seedling vigor index and higher activities of seed stored food mobilizing enzymes (α-amylase and protease). Foliar application of Zn-TNE (0.01-0.06%, v/v) enhanced defense-antioxidant enzymes activities, balanced reactive oxygen species, induced higher content of chlorophyll-a, b and higher lignin deposition in soybean plants. In the field, Zn-TNE application (0.02-0.06%, v/v) significantly controlled bacterial pustule disease (PEDC value 28-79%) and increased grain yield up to 16.6% as compared with bulk thymol application and up to 50% from control. Disease control and higher yield in soybean could be explained by diverse bioactivities of Zn-TNE in maintaining cellular homeostasis of soybean plants. Study shows that Zn-TNE can further be maneuvered for slow delivery of other micronutrients for higher crop yield.