Vigna radiata, commonly known as green gram, moong, or mung, is a valued legume that forms an integral part of the human diet. It is a rich source of protein, vitamins, minerals and dietary fiber and contains significant amounts of bioactive compounds.
Vigna crop is also grown under crop rotation regimes for its ability to enhance crop fertility
(Singh et al., 2016a; Singh and Bell, 2021). Globally 7.3 million ha of agricultural land is under mung bean cultivation producing 5.3 million tons (2015-17), with India and Myanmar each supplying almost 30%, China 16% and Indonesia 5% (
Brassica, 2016;
Nair et al., 2022). In 2022 the global market size of mungbean reached US$ 4,221.5 million (
Mung Beans Market: Global industry Trends, Share, Size, Growth, Opportunity and Forecast 2023-2028, Report ID-SR112023A648). Mungbean is grown on an area of 5.13 million hectares in India with the total production of 3.09 million tonnes with a productivity of 601 kg/hectare in 2020-21 (
Annual report 2021-22, Directorate of Pulses Development, Ministry of Agriculture and Farmers Welfare, Govt. of India). Mungbean yield potential varies between 2.5-3.0 tonnes/hectare however, the average productivity is strikingly low at 0.5 tonnes/hectare. The reduced productivity is attributed to various biotic stresses such as insect, bacterial and viral infections and abiotic stresses such as salinity, drought, heat stress and waterlogging
(Nair et al., 2019; Ambreen et al., 2021).
Amongst the abiotic stresses, one of the leading factors restricting legume productivity is salinization
(Raun et al., 2002). It is estimated that NaCl at a concentration of 50mM can cause more than 60% yield loss of
Vigna radiata (
Desai et al., 2022). With rapidly increasing salinization of soils due to natural as well as anthropogenic activities, an estimated loss of 50% of cultivable land is expected by 2050
(Saha et al., 2010; Hasanuzzaman et al., 2013). Salinity stress influences nearly all phases of growth of leguminous plants, most specifically, the germination, vegetative and reproductive phases (
Mounia Mansouri and Kheloufi, 2017). Seed germination and seedling emergence stage are highly susceptible to salt. Healthy and higher yield can be assured by enhancing the quality of seed sown and efficient seed germination (
Haider and Ur Rehman, 2022). Seed priming is a promising method of enhancing seed germination under abiotic stress
(Bose et al., 2018). It offers the advantage of overcoming slow and non-uniform germination, low seed vigor, poor crop stand and poor product quality. It also eases germination even under adverse conditions, lifts crop performance and enhances yield potential
(Marthandan et al., 2020). The technique has emerged as a viable strategy for enhancing crop yield under stressful condition.
Physiologically seed priming regulates the temperature and moisture content of the seed, bringing it closer to germination without the need for agrochemicals and other labor-intensive and soil-degrading agricultural methods. Both chemical, as well as organic priming agents have yielded positive results. Chemical priming using salts like Sodium Chloride (NaCl), Potassium Chloride (KCl), Potassium Nitrate (KNO
3), Hydrogen Peroxide (H
2O
2)
etc. are known to be effective due to their involvement in the alleviation of abiotic stresses such as water deficit or salt stress by providing nutrients for growth or modulation of cytoplasmic activities under stress (
Miladinov et al., 2019;
Muñoz-Salinas, 2021). Organic priming agents such as extracts of Moringa leaves are known to contain metabolites like polyphenols, flavonoids and isothiocyanates, which afford defense against pathogens and UV rays
(Ambreen et al., 2021). Similarly, Neem leaf extract exhibits a synergistic effect on early and uniform seed germination and enhances tolerance to pests and diseases during the early crop stage (
Abeysekera, 2021). Cow urine-based priming enhances crop yield and quality as it has nutrients like phosphorus and nitrogen
(Satani et al., 2021).
Seed priming is an economical and soil-friendly option however, it is not widely used. Limited seed priming options are available to farmers. Organic priming methods with the advantage of having no negative environmental impact need to be explored further. The present study aimed to evaluate the effect of selected seed priming agents (chemical, organic and hormonal) on
Vigna radiata (mung), under salt stress aiming to provide an efficacious seed priming strategy.