In recent years, foliar applications of nanoparticles are increasingly being employed in agricultural fields as fertilizers to enhance crop yields. However, limited studies are available on the foliar uptake of nanoscale nutrients and their interaction with plants. In this study, we reported the effects of foliar spray with varied concentrations of nanoscale silica (N-SiO2) and bulk tetraethyl orthosilicate (TEOS at 2000 ppm) on the growth and yield of groundnut. Nanosilica was prepared by a sol–gel method and characterized by transmission electron microscopy, dynamic light scattering, and X-ray diffraction. The size and zeta potential of N-SiO2 were found to be 28.7 nm and 32 mV, respectively. The plant height, number of branches, total dry weight, SPAD chlorophyll meter reading, photosynthetic rate, water use efficiency, number of nodules, and ascorbic acid content were increased significantly with the N-SiO2 foliar application at 400 ppm over control. The number of filled pods increased significantly by 38.78 and 58.60% with N-SiO2 at 400 ppm application over TEOS and control, respectively. The pod yield per plant in N-SiO2 at 400 ppm increased by 25.52 and 31.7% higher over TEOS and control, respectively. Antioxidant enzyme activities enhanced significantly in N-SiO2 at 200 and 400 ppm over control, indicating a stimulatory effect on the plant growth. In addition, confocal microscopy revealed that fluorescein isothiocyanate (FITC)-N-SiO2 entered through stomata and then transported to vascular bundles via apoplastic movement. Our study for the first time demonstrated that N-SiO2 can significantly modulate multiple complex traits in groundnut through an eco-friendly and sustainable approach.

Application of nanoscale materials in agriculture for various reasons, including plant nutrition, has been an interesting multidisciplinary research component. Among the plant nutrients, silica plays an important role as a quasi-essential nutrient besides enhancing resistance against disease and pests in the plant system. In the present investigation, we report the effects of foliar spray (field experiment) of varied concentrations (250, 500, and 750 ppm) of nanoscale silica (NSiO2) and osic acid (350, 700, and 1050 ppm) on structural and biochemical processes and yield in chilli (Capsicum annuum L.). NSiO2 was prepared using the sol–gel method and characterized by UV–vis spectroscopy, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The DLS analysis revealed the size (26.2 nm) and ζ-potential (−43.6 mV) of NSiO2. Significant increases in plant height, chlorophyll content, carotenoids, lycopene, and superoxide dismutase enzymatic activities were recorded with particulate NSiO2 foliar application at 750 ppm. Further, we are the first to report that foliar application of particulate NSiO2 led to the formation of a silicic acid layer on epidermal cells in chilli. Hence, foliar application of particulate nanoscale silica increases the flexural rigidity of epidermal cells, the chlorophyll content, carotenoids, lycopene content, and yield in chilli.

Background: Drought is a leading abiotic factor limiting groundnut production globally. Therefore, the screening and development of moisture stress tolerant groundnut genotypes is a key issue towards sustainable agriculture. Methods: An experiment was laid in a split plot design taking two conditions, control (T1) and moisture stress (T2) as main treatments and 7 genotypes of groundnut as sub treatments. Several morpho-physiological traits like dry matter production, dry matter partitioning, photosynthetic traits, relative water content, were measured after 10 days of stress imposition. Yield and yield attributes were also recorded at harvest along with drought tolerance index and principal component analysis. Result: Results showed significant differences among the genotypes at moisture stress and control conditions. Significant decrease was observed in chlorophyll content, total dry matter production, dry matter partitioning efficiency, relative water content, photosynthetic traits, except specific leaf area among all the genotypes. TCGS-1694 have been identified as moisture stress-tolerant genotypes in principal component analysis with higher efficiency interms of total dry matter production, photosynthetic rate, dry matter partitioning to pods, stress tolerance index, yield and yield attributes while Kadiri-6 has been identified as susceptible genotype.