The growing accumulation of agricultural waste, particularly groundnut shells, presents significant environmental concerns due to methane emissions and greenhouse gas release from crop residue burning. Groundnut shell powder, a biodegradable byproduct, offers potential as a raw material for bio-nanocomposite films. This study focuses on the development of biodegradable packaging films from groundnut shell powder, evaluating their physicochemical and mechanical properties while optimizing process parameters. Experiments were conducted to optimize the process parameters, viz., shaker time (6, 12, and 18 h), shaker speed (160, 180, and 240 rpm), and concentration of laccase enzyme (80, 100, and 120 mg) to leach out maximum lignin content in short duration. Further, to stop enzymatic reaction, drying time, drying temperature, and storage condition (dark or light) were optimized to minimize the time of operation, maximize cellulose, and minimize lignin content for isolation of cellulose microfibers from peanut shell powder. The biodegradable film from groundnut shell powder was developed by solution casting method. The three types of films, viz., agar powder-based (AG), mixture of agar powder and peanut shell powder (PSP), and mixture of agar powder and cellulose microfiber (CMF), were developed at optimized conditions. The maximum thickness was achieved by the cellulose microfiber-based film. The transmittance value of agar film was lesser than that of CMF film and PSP. The CMF film's water solubility and tensile strength was observed highest in comparison to that of the other two films. CMF and PSP films had a higher opacity value than agar films. Due to the presence of lignin, it was found that PSP loses less weight than CMF film during the soil burial degradation test. Therefore, the findings suggested that CMF film possesses not only improved biodegradability but also superior physical and mechanical properties, which may be suitable for use as a food packaging material.

Context or problem: As global temperatures steadily increase, the frequent occurrence of extreme hightemperature events has significantly hampered peanut (Arachis hypogaea L.) production in low-latitude regions. Objective or research question: Previously, 24-epibrassinolide (EBR) was identified as a substance capable of mitigating abiotic stress damage in plants. However, it remains unclear whether and by what mechanisms EBR can diminish the yield loss caused by heat stress in peanuts. Methods: During the flowering phase, two distinct peanut cultivars, Qinghua7 (heat-resistant type) and Shanhua101 (heat-sensitive type) were exposed to a 10-day heat stress treatment (+4.2 degree celsius). EBR or water was sprayed on the 1st, 3rd, and 5th days of heating, and water-sprayed natural peanuts was used as control, to assess the effect of EBR on antioxidant capacity, photosynthetic performance, and yield in heat-stressed peanuts. Results: EBR application increased activities of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase in heat-stressed peanut leaves. Simultaneously, EBR decreased hydrogen peroxide and superoxide anion production, along with a reduction in malondialdehyde content. Additionally, EBR notably alleviated the oxidation damage to chloroplast membranes and grana lamella under heat stress. Thus, an increase in maximum photochemical efficiency, comprehensive performance index, rubisco activity, net photosynthetic rate, and biomass accumulation was observed in heat-stress peanuts. Synergistic enhancement provided by EBR on antioxidant capacity and photosynthetic performance resulted in improved plant growth, kernel weight, and effective pods per plant, led to a reduction in yield loss for heat-stressed cultivars Qinghua7 and Shanhua101 by 26.92 % and 55.18 %, respectively. Conclusions: The application of EBR enhanced the antioxidant capacity of peanut leaves. This, in turn, mitigated oxidative damage to chloroplast membranes, resulting in improved photosynthetic performance. Ultimately, this intervention led to a reduction in yield loss for heat-stressed peanuts, achieved through an increase in kernel weight. Implications or significance: The foliar spraying of EBR holds significant promise in crop production, offering a broad application prospect. This practice is beneficial for enhancing the heat resistance of peanuts and potentially other field crops, equipping them to better withstand the increasingly severe climate challenges anticipated in the future.

Aim: To determine the optimum level of phosphorus for higher yield and phosphorus uptake by groundnut at different planting densities. Methodology: A field experiment was laid out in randomized block design with factorial concept during Rabi seaon 2019-20 to study the phosphorus uptake by groundnut under high density plantation (22.5 x 10 cm - 4.44 lakh ha(-1) ; 20 x 7.5 cm - 6.66 lakh ha(-1) ; 22.5 x 5 cm - 8.88 lakh ha(-1) with graded levels of phosphorus (25, 37.5, 50 and 62.5 kg P2O5 ha(-1) ). Results: The present study revealed that 4.44 lakh ha registered lower phosphorus uptake and application of 62.5 kg P2O5 ha recorded a higher uptake of phosphorus and soil available nitrogen, phosphorus, and potassium. Interaction was significant only in influencing pod yield. Higher pod yield was recorded in the population density of 4.44 lakh ha applied along with 50 kg P2O5 ha , followed by 6.66 lakh ha applied with 62.5 kg P O ha(-1) . Interpretation: The results indicate that for better nutrient uptake and higher pod yield of groundnut, farmers should prefer a planting density of 6.66 lakh ha(-1) with an application of 62.5 kg P2O5 ha(-1) .

Background: Heavy metal toxicity affects plant growth and alters physiological processes. Soils in many areas are often contaminated by cadmium and zinc which show varied response on plants by their interactive effects. The experiment was done to study the effect of cadmium and zinc as sole presence and in combination in groundnut seedlings. Methods: The laboratory experiment was conducted on groundnut cultivar TG 51 in sand culture using modified Hoagland solution. After initial screening, three concentrations of cadmium (Cd 100, Cd 300 and Cd 500 mu M) and two concentrations of zinc (Zn 50 and Zn 150 mu M) were selected for studying their effects individually and in combination on physiological and biochemical parameters. Result: The reduction in root length increased over control as the concentration of cadmium in the medium increased. Cadmium or zinc alone led to a decrease in chlorophyll a, b and relative water content of the leaf. Zinc supplement at 150 pM not only mitigated the negative effect of Cd 100 pM and 300 pM, but also increased the chlorophyll content above control level. Zinc supplement not only increased the protein content over the control but also mitigated to some extent the adverse effects of cadmium in protein content when applied in combination. Under both cadmium and zinc treatment, the inhibition of nitrate reductase (NR) activity over unstressed control was found. Different treatment combinations, however, reduced the negative effects of cadmium, although zinc could not completely override such damage, change the level of toxicity. Treatment with Cd 100 pM and 300 pM induced an increase in phenol content over the control, while higher concentration (500 pM) of the metal led to a decrease in this potent antioxidant compound. Presence of Zinc in the growing medium significantly enhanced the accumulation of phenolic compounds highlighting its protective role against oxidative damage.

Peanut smut (causal agent Thecaphora frezzii) and seasonal drought are the two main factors reducing peanut yields in Argentina. There are no previous studies about the effect of drought on peanut smut occurrence. We evaluated the effect of soil water limitation on smut symptoms in greenhouse and field assays. Additionally, we analysed the biochemical responses of plants to the combined stress caused by water limitation and smut infection in greenhouse experiments. We found that a moderate water deficit (30% of soil water-holding capacity) increased smut symptoms and differentially increased proline and reduced chlorophylls in the host. Subsequently, we studied the correlation between field precipitation data and smut damage from 2015 to 2020 in naturally infected fields with a high T. frezzii spore load in the soils. Strong correlations between precipitation and severely affected pods, severity disease index and incidence were found from January to March (susceptibility window for T. frezzii infections). We suggest a strategy of irrigation in a specific time frame to mitigate smut damage when there is a water deficit in the growing season.