Vengatasamy Vakeswaran

Phytohormones are small molecules that act as signalling molecules in plant growth and development, seed dormancy, seed germination and environmental stress responses and they interact with one another through interconnected signalling pathways. Among these, abscisic acid (ABA) and gibberellins (GA) have antagonistic functions in seed development and germination. Abscisic acid prevents seed germination and increases stress tolerance while GA stimulates embryo development, radicle emergence and seedling establishment. Besides their well-known roles in plant defence, jasmonic acid (JA) and salicylic acid (SA) are involved in the regulation of seed germination and early plant growth. In general, jasmonoyl-isoleucine (JA-Ile) inhibits germination, while its precursor, 12-oxo-phytodienoic acid (OPDA) promotes germination under certain physiological conditions. Likewise, the effects of SA on seed germination and stress responses depend on its concentration. These phytohormones participate in interconnected signalling pathways involving key regulators such as ABI5 (ABA insensitive 5), DELLA (aspartic acid-glutamic acid-leucine-leucine-alanine) proteins, jasmonate zim-domain (JAZ) repressors and non-expressor of pathogenesis-related genes 1 (NPR1). Although the individual roles of ABA, GA, JA and SA have been described, their interconnected signalling networks and molecular interactions that regulate seed dormancy, germination and plant growth remain poorly understood. This review summarises the molecular and physiological mechanisms underlying the interactions and crosstalk among these phytohormones and emphasises the role of their coordinated interactions in the regulation of seed dormancy, germination and plant growth.

Seed enhancement technologies provide eco-friendly alternatives to synthetic protectants for improving crop establishment under stress. In the present study, organic seed pelleting and coating formulations were developed using volcanic ash (as a silicon-rich mineral source), biochar and a microbial consortium. These formulations were evaluated in brinjal (Solanum melongena L.) cv. CO 2 under biotic stresses imposed by Fusarium oxysporum and Pythium aphanidermatum. Results revealed that both pelleting and coating significantly improved seed germination, seedling vigor, root and shoot growth and biomass accumulation compared to the untreated seeds (control). Among various seed treatments, seed pelleting mixture at 500 g kg-1 seed and seed coating formulation at 4 g kg-1 seed consistently outperformed others, recording higher emergence, leaf area and chlorophyll content even under pathogen pressure. The superior performance of these treatments is attributed to the synergistic effects of silicon-mediated structural defense, nutrient mobilization by biochar, phytohormone stimulation and pathogen suppression by microbes and biocontrol agents. This study demonstrates the potential of integrating mineral-based carriers with microbial inoculants in organic seed enhancement technologies to strengthen seedling establishment and resilience against biotic stresses. Thus, eco-innovative formulations provide a sustainable strategy to reduce pesticide dependence and enhance crop productivity in solanaceous vegetables.

Climate change is a major global concern that adversely affects seedling emergence and crop development during critical growth stages. Thus, as a preventive measure and short-term strategy, seed priming is performed to boost germination and early growth of plants. Chemical seed priming has drawbacks, including high cost, selectivity and impact on target species, soil contamination and environmental pollution. Although plant genetic engineering, has advanced significantly developing resistant varieties remains a slow and unpredictable process. Technological advancements have created a path for future research on the improvement of current environment friendly seed enhancement methods with assured enhancement in seed vigour and crop productivity. Hence, organic seed priming serves as substitute due to their socioeconomic benefits and environmental safety. It represents an agro-ecological approach grounded in the principles of self-sufficiency, biodiversity, recycling and reduced dependency on chemical inputs. Soon, the organic seed priming is expected to exhibit fastest growth in the seed industry, partly due to its ease of registration with the environment regulatory agencies. Therefore, this reviews a few highlights preferred organic seed priming techniques, recent advancements and their significance in sustainable agriculture.

The presence of Benzene in aqueous solution is a great concern for the health-related issues of the living things that consume the same. Among various removal methods, the adsorption method with volcanic ash is a less laborious and eco-friendly process. With this notion, the seeds and grains of maize COH (M) 8 were coated with volcanic ash and they are utilized in this study as a biological entity to remove the benzene from the aqueous solution. Volcanic ash was characterized using FTIR, XRD, and FE-SEM-EDAX analyses, revealing key structural features, including sulfoxide functional groups, a crystalline size of 179.06 nm, and particle sizes ranging from 36.24 to 234.60 nm. Batch experiments were conducted to optimize adsorption and degradation efficiencies under different conditions. A maximum degradation efficiency of 80.62 % was achieved at a benzene concentration of 10 µg/mL within 1 hr. The efficiency increased to 87.96 % with a higher catalyst dosage at a benzene concentration of 50 µg/mL over 5 hr. Acidic conditions (pH 3) further enhanced the efficiency to 81.43 % over 5 hr. Under sunlight irradiation, a maximum degradation efficiency of 83.54 % was achieved within 1 hr. These findings establish volcanic ash as a promising, eco-friendly material for benzene adsorption in aqueous solutions, with the added advantage of enhancing seed germination and growth parameters. Its abundant availability and cost-effectiveness make it a sustainable solution for environmental remediation and agricultural applications.

Efficient seed storage is crucial for maintaining seed quality, viability, and germination potential, which directly impact agricultural productivity and food security. However, prolonged storage leads to seed deterioration due to both biotic and abiotic factors, resulting in significant post-harvest losses. Modified atmospheric packaging (MAP) is a sustainable non-chemical technology that enhances seed storability by altering the gaseous environment around seeds. MAP operates through active packaging, which injects desired gases and passive packaging, where the product’s respiration modifies the atmosphere. By reducing oxygen (O2) levels, minimizing moisture absorption, and inhibiting microbial and insect activity, MAP extends seed shelf life. Typically, O2 is replaced with nitrogen (N2) or carbon dioxide (CO2), limiting oxidative reactions and metabolic activity. MAP benefits multiple seed types, including cereals, legumes, oilseeds, and horticultural crops. Physically, it reduces seed moisture, delaying deterioration and preserving seed coat color. Physiologically, it prolongs seed longevity by reducing the accumulation of reactive oxygen species (ROS) and conserving seed reserves. Biochemically, it minimizes lipid peroxidation, maintains enzyme activities like alpha-amylase and catalase and reduces electrolyte leakage. Additionally, MAP controls storage pests and pathogens; elevated CO2 inhibits insect proliferation and fungal contamination, mitigating mycotoxin risks. This review examines the strategic role of MAP in seed conservation for sustainable agriculture by comparing MAP with traditional storage methods and assessing its impact on seed viability and longevity.

The storage of biodiesel feedstock presents significant challenges for the biodiesel industry due to the deterioration of fatty acid constituents, which compromises both oil and biodiesel quality. Seed viability plays a critical role in preserving the quality of oil within biodiesel feedstock during storage. Recognizing the need for an affordable and efficient storage solution, this study aimed to develop a method for preserving the physiological and fuel characteristics of groundnut seeds (biodiesel feedstock) under tropical conditions. Groundnut seeds with a moisture content of 6.4% and an initial viability of 91% were stored in 3 different types of container: cloth bags, evacuated aluminum foil pouches and CO2-infused plastic containers for 7 months under ambient tropical conditions (34 ± 2 °C, 56 ± 4% RH). The study assessed the impact of storage conditions on seed viability, antioxidant enzyme activity and oil quality parameters, including free fatty acid (FFA), acid value (AV), peroxide value (PV), saponification value (SV), iodine value (IV) and cetane number (CV). Results indicated that CO2-infused plastic containers effectively maintained seed viability (72%), enhanced antioxidant enzyme activity and minimized oil deterioration. Furthermore, the feedstock stored in these containers complied with international biodiesel standards and remained suitable for alkali-based trans-esterification processes. This cost-effective storage method offers a viable solution for preserving biodiesel feedstock storage in tropical climates, thereby ensuring year-round biodiesel production and supply.

The yield of sunflowers is impacted by inadequate source-sink connections. There are no vascular bundles in the center of the capitulum, resulting in low seed setting and filling. It was hypothesized that manipulation of resource availability to peripheral and intermediary seeds by eliminating the predominantly ill-filled seeds of the capitulum core would have an augmenter effect on the filling of seeds in the rest of the two regions. A field experiment was conducted to achieve capitulum core destruction by operating a newly designed hand-held battery-operated ‘capitulum core destructor’, capable of removing the core area to a diameter of 0.8 and 1.5 cm. . Field experiments were conducted to standardize the optimum stage for capitulum core destruction (R5.0- 0% flowering of the capitulum total area (disc florets), R5.1- 10% flowering, R5.4- 40% flowering, R5.8- 80% flowering) and optimum area of core destruction (0.8 and 1.5 cm of inner diameter). The results revealed that the core destructed treatments outperformed the control (T1) in terms of seed yield and seed quality attributes. Amongst the treatments, T5 (1.5 cm core destruction at R5.8 stage) showed a 21% increase in seed yield over the control and registered the highest total number of seeds, total seed weight (48.63 g) and 100-seed weight (g). Additionally, the T5 treatment improved seed recovery percentage (80.23% compared to 70.45% in the control) and reduced rejected seed percentage (19.76% compared to 29.54% in the control). Concomitantly, the resultant seeds of T5 (1.5 cm core destruction at R5.8 stage) also possessed the highest germination potential, speed of germination, seedling growth and vigour index. This study demonstrates a scalable approach for sunflower cultivation globally, offering a practical solution to enhance yield and quality. Therefore, it was concluded that capitulum core destruction optimized resource allocation among the periphery and middle whorls of the capitulum, thereby resulting in a significant augmentation of seed yield and quality potential in sunflower crops.

The demand for rice is predicted to rise by over 200 million tons by 2050 due to the rapidly growing population. India needs to step up its rice production because of the burgeoning population and decreasing land and other resources. Existing lower yield in rice caused by improper planting methods, particularly related to transplanting. This research was conducted to understand the effect of planting methods with coated and uncoated seeds to maximize seed yield and quality of rice. A field was raised in a randomized block design (RBD) on different treatments as coated and uncoated seeds with methods of sowings such as drone sowing, drum sowing, machine transplanting and manual transplanting with three replications. The observation on the number of hills m-2, number of tillers m-2, number of productive tillers m 2, number of grains panicle-1, 1000-grain weight, rice yield m-2 and quality indicators were gathered. The result indicates the maximum seed yield and productive tillers per hill recorded in drone seeding with coated seeds (59.71 q ha-1 and 31.75, respectively) whereas uncoated manual transplanting recorded 51.68 q ha-1 and 25.0 numbers, respectively in rice variety CO 55. Further, results on seed quality parameters revealed that machine transplanting yields higher production with the best seed quality compared to the seeds from drone sowing. It is concluded that drone sowing and machine transplanting are superior in seed yield and quality than conventional manual transplanting. Further research on enhancing the seed productivity through drone sowing on seeding density, population maintenance and productive tiller enhancement can be done.

Delinting is widely used process aimed at removing residual lint from cotton seeds after ginning to enhance the efficiency of mechanical planting and improve germination rates. However, concerns have been raised regarding its potential impact on seed coat integrity and overall seed vigor. The seed coat serves as a crucial protective barrier that shields seeds from microbial infections, regulates water uptake during imbibition and plays a significant role in maintaining seed longevity. Damage to this protective layer can reduce germination rates, lead to abnormal seedling development and increase susceptibility to pathogens, ultimately compromising the seed quality. This review synthesizes current research on the effects of acid delinting on seed coat integrity and its implications for seed vigor. Various factors, including water absorption dynamics, electrical conductivity, seed viability and changes in mineral and metabolite composition, are analyzed to understand the extent of damage caused by delinting. Furthermore, this review examines various methodologies and testing protocols used to assess seed vigor in relation to seed coat integrity. This work aims to enhance our understanding of strategies that balance improved seed germination with the preservation of seed health. The insights from existing studies can help develop better testing methods to spot cotton seed lots with weaker seed coats. This can also support efforts to keep seeds viable during storage and ultimately improve productivity.

A study was conducted at the Department of Floriculture and Landscape Architecture Laboratory to investigate the influence of various nutrient formulations on the post-harvest quality of tuberose using a knapsack sprayer and drone. The treatments involved spraying macro and micronutrients along with growth regulators at different concentrations. Throughout the experiment, all parameters were recorded at 2 days intervals. Drone spray of MN mixture + 0.5 % poly feed + 0.6 % humic acid + 150 ppm GA3 recorded the maximum plant post-harvest quality attributes over other treatments. It showed increased post-harvest quality attributes, including relative water content percentage of flower (95.15 %), physiological loss of weight percentage of flower (14.83 %), shelf life at room temperature (3.79 days) and vase life (12.45 days). Additionally, the treatment was found to be the best for parameters of water uptake (38.45 g) and percentage of floret opened (27.02). Plots treated with drone spray of MN mixture + 0.5 % poly feed + 0.6 % humic acid + GA3 at 150 ppm showed a reduced rate of transpiration loss of water (14.89 g) and electrolyte leakage (12.52). The experimental findings demonstrated that foliar application of nutrients along with growth regulators at different concentrations using drones improved the post-harvest quality of tuberose.