Soil contamination with toxic cadmium (Cd) is becoming a serious global problem and poses a key hazard to environments and the health of human beings worldwide. The present study investigated the effects of foliar applications of three forms of silicate chemicals (calcium silicate, sodium silicate, and potassium silicate) at four rates (0.25%, 0.5%, 0.75%, and 1.0%) at tillering stage on rice growth and the accumulation of Cd under Cd stress (30 mg kg⁻¹). The results showed that Cd stress reduced the yield-related traits and enlarged Cd contents in different rice organs. The leaf gas exchange attributes and yield traits were enhanced, and the Cd accumulation and bioaccumulation factor in rice organs were reduced, especially in grains, through silicon application. In shoots, roots, and grains, foliar spray of Si reduced Cd contents by 40.3%, 50.7%, and 47.9%, respectively. The effectiveness of silicate compounds in reducing Cd toxicity varied with the kind of chemicals and doses of foliar applications. Foliar application of potassium silicate, at a rate of 0.5%, at tillering stage, showed the best effectiveness in improving grain yield, while mitigating Cd accumulation in rice grains. The outcome of this study provides a promising practicable approach in alleviating Cd toxicity in rice and preventing the entrance of Cd into the food chain.

Zinc plays an important role as a micronutrient in both animals and plants. The application of zinc oxide nanoparticles as a potential solution to alleviate zinc deficiency and its effect on the growth of seedling attributes of wheat. These particles were prepared by precipitation and sol-gel method using zinc sulfate and zinc chloride as precursors. The prepared samples were characterized by Scanning electron microscopy and Fourier-transform spectroscopy. Zinc oxide nanoparticles were found to be elliptical in shape and their diameter ranges were observed 10.6 to 10.7nm by Scanning electron microscopy. Fourier-transform spectroscopy analyses showed the presence of the various functional group in the zinc oxide nanoparticles like N-H, CH2, CH3, RCH=CHR, C=O, -COOH, -OH and CH2-Cl. Solutions of different concentrations of zinc oxide nanoparticles (0.1%, 0.2%, 0.3%, 0.4%, 0.5%) were prepared and seeds were soaked in distilled water (hydro priming). After the 6 days observations, it was found that nanoparticles (0.3%) prepared from the zinc sulfate by sol-gel method showed significant variation for germination and seedling attributes of wheat as compared to control. The decreasing order for the zinc chemicals was zinc sulfate nanoparticles > zinc chloride for methods sol-gel method > precipitation method > standard (original salt) and for the levels was 0.3% > 0.2% > 0.4% > 0.5% > 0.1% > hydro priming > control. In crux, nanoparticles prepared from zinc sulfate enhanced the germination of wheat as compared to control.