Carbon Dots (CDs) were synthesized from peanut shells (PNS) through pyrolysis and characterized using FTIR, XRD, HRTEM and BET analysis revealing an average size of 2–5 nm with amorphous nature. Synthesized PNS-CDs was employed both as priming and foliar agent for enhancing seed quality and crop productivity in blackgram (Vigna mungo L. Hepper). Different concentrations ranging from 50, 100, 200, 300, 400, 500 and 1000 ppm was used for seed priming and 5, 10, 15, 20, 25, 50, 75 and 100 ppm were given as foliar spray on 30^th and 45^th days after sowing (DAS). On accounting the best seed priming and foliar spray concentrations, field trial was conducted to validate the optimistic effect of PNS-CDs on blackgram crop productivity. Results revealed that priming with 200 ppm for 3 h exhibited maximum seed imbibition (54%), germination (88%) and vigour index (3165). Whereas, foliar spray with 50 ppm expressed significant improvement in leaf area index (2.6), total chlorophyll (2.70 mg/g), total soluble protein (71 mg/g), Number of nodules/plant (138), seed yield/plant (8.7 g) and 100 seed weight (5 g). The impact of PNS-CDs treatments resulted in increased photosynthetic rate (12.45 µmol CO₂ m⁻²s⁻¹), transpiration rate (3.13 mmol H₂O/m⁻²s⁻¹), stomatal conductance (0.55 mol H₂O/m⁻²s⁻¹) and internal leaf CO₂ concentration (652 µmol CO₂ m⁻²s⁻¹) which ultimately enhanced the photosynthetic efficiency of plants. It has also exhibited a promising effect on the resultant seed in which the combination seed priming (200 ppm) followed by foliar spray (50 ppm) recorded maximum 100 seed weight (4.19 g), germination (97%) and vigour index (3019). Thus, this study highlights the promising role of PNS-CDs as a sustainable and effective agricultural nanomaterial, offering a novel approach to utilize the agricultural waste and also to enhance the crop productivity through advanced non-chemical approach.

Among the abiotic factors that causes threat to crop production, drought is one of the foremost constraints in the changing climatic era. Hence, a study was conducted to mitigate the effect of drought stress in blackgram with the peanut shell carbon dots (PNS-CDs) as seed priming and foliar spray agent. Blackgram seeds were primed with PNS-CDs at 200 ppm for 3 h and plants were sprayed with PNS-CDs at 50 ppm on 30^th and 45^th DAS under drought stress conditions (30%, 50% and 75% WHC). The imposed treatments included dry seeds (control), water sprayed plants, seed priming with PNS-CDs, foliar spray with PNS-CDs and combination of both. The results demarcate the exemplary performance of plants when given with combined application of priming (200 ppm) and foliar spray (50 ppm) with PNS-CDs in terms of its growth and yield. Further, an increased activity of catalase (12%), peroxidase (12%), superoxide dismutase (22%), glutathione reductase (60%), ascorbate peroxidase (55%), H₂O₂ scavenging (32%) and proline (35%) were noticed over dry seeds, which confirmed the antioxidant defense mechanism offered by PNS-CDs. In addition, the percentage increase in photosynthetic parameters like total chlorophyll (44%), total soluble protein (54%), photosynthetic rate (89%), stomatal conductance (40%), internal CO₂ concentration (74%) and chlorophyll stability index (51%) confirmed the role of PNS-CDs as photosynthesis enhancer under drought stress, which resulted in enhanced stress tolerance, plant growth and yield. Thus, it was found that priming blackgram seeds with 200 ppm PNS-CDs for 3 h followed by foliar spray with 50 ppm on 30 and 45th DAS could serve as a sustainable alternative to chemical inputs, ensuring better crop productivity and stress tolerance in water-limited environments. Further, future research could explore the molecular mechanisms underlying the stress tolerance offered by PNS-CDs. In addition, the application of PNS-CDs to different crops, biotic and abiotic stress conditions will also pave the way for broader agricultural sustainability in an eco-friendly approach.

Blackgram seeds soaked in the liquid cultures viz., Rhizobium @ 1: 50 dilution for 3 h or phosphobacteria @ 1:50 dilution for 4 h or PPFM @ 1:100 dilution for 3 h have showed the increased germination and vigour. Among the cultures, PPFM performed better with the population of 3 x 104 cfu g-1 of seed during three months storage. Also, increased seed vigour was found in the seed infusion treatment with microbial consortia viz., Rhizobium @1:50 dilution + PPFM @1:100 dilution (1:1) for 3 h with the populations of 3 x 104 and 2 x 104 cfu g-1 of seed respectively. In addition, the seed infusion with PPFM liquid culture @ 1:100 dilution for 3 h followed by polymer coating @ 5 ml kg-1 or carbendazim treatment @ 2 g kg-1 or polymer coating @ 5 ml kg-1 + carbendazim treatment @ 2 g kg-1 of seed have recorded the increased germination and vigour. However, the reduction in bioinoculants population was noticed when the seeds treated with carbendazim fungicide. Nevertheless, the minimum population of 1 x 104 cfu g-1 of seed was recorded in the fungicide treated seeds.

Background: Now-a-days, use of machines is becoming important due to shortage of labour for field operations. One such case is seed drill sowing which warranted enough seed size for easy sowing. Pelleting of seed is one of the techniques through which the size of the seed can be increased thereby it can be sown easily by seed drill. Green gram is one of the important pulses which needs pelleting technique for mechanized sowing. Methods: The experiments on standardization of seed pelleting technique and evaluating under field conditions were conducted in the Department of Seed Science and Technology, Seed Centre, Tamil Nadu Agricultural University, Coimbatore, India during 2019-2022. The green gram var. CO 8 seeds were primed and pelleted with TNAU pelleting mixture. Then, the pelleted seeds were sown by pneumatic seed drill and evaluated for its field performance. Result: The results showed that the green gram seeds primed with MnSO4 @ 0.5% and pelleted with 7 layers of TNAU pelleting mixture along with imidacloprid 70 WS @ 7 g/kg have recorded increased seedling vigour without affecting the seed germination. Also, the seeds sown by seed drill have recorded with better plant growth traits and higher yield. Also, single seed placement was achieved by seed drill sowing and about 25% seeds can be saved.