Seaweed-Based Biogenic ZnO Nanoparticles for Improving Agro-morphological Characteristics of Rice (Oryza sativa L.)

To develop sustainable nano-agriculture, biogenic ZnO nanoparticles have been prepared using brown seaweed Turbinaria ornata (T. ornata) extract as a priming agent to promote rice seed quality and crop yield attributing to rice seeds. The results of various physico-chemical characterization analysis indicate the formation of ZnO nanoparticles. Rice seeds primed with seaweed-based biogenic ZnO nanoparticles at 10 mg/L showed that there has been enhancement in the seed germination (100%), shoot length (100 mm), shoot width (1.0 mm), root length (185.0 mm) root width (0.5 mm), seedling length (216 mm), leaf length 33.0 mm), leaf width (2.0 mm), seedling vigor (28,500 vigor index) and dry matter production (DMP) compared to the conventional hydropriming. Consequently, a micro-plot experiment has been conducted with foliar application of biogenic ZnO nanoparticles and the results revealed that at 10 mg/L recorded improvement in grain weight (653 g/m(2)), seed length (8.0 mm), seed thickness (1.71 mm) and seed width (3.23 mm) compared to hydroprimed seeds under. HR-SEM micrograph confirms the presence and assimilation of biogenic ZnO nanoparticles in treated seed/foliar applied leaf of rice plant. Further, ICP-MS analysis also confirmed the increase in Zn content in the nanoprimed rice seedlings and foliar applied rice crop in a dose-dependent manner. The experimental results thus demonstrate that the application of seaweed biogenic ZnO nanoparticles improving agronomical characteristics of rice.