The impact of boron seed priming on seedling establishment, growth, and grain biofortification of mungbean (Vigna radiata L.) in yermosols

Boron-deficiency in Yermosols is among the major constraints to mungbean productivity and grain biofortification in Pakistan. However, agronomic strategies such as boron (B) seed priming have potential to improve mungbean yield and grain biofortification. Moreover, deficiency to toxicity range for B is very narrow; therefore, it is pre-requisite to optimize its dose before field evaluation. A wire house experiment was planned out to reconnoiter the impact of seed priming with B on growth and quality of two cultivars of mungbean, i.e., ‘NM-2011’ and ‘NM-2016’. Four different B levels were used as seed priming, i.e., 0.01%, 0.05%, 0.1% and 1.0% B, (borax Na(2)B(4)O(7).10H(2)O, 11.5% B) were tested, whereas hydropriming was regarded as control. Seed priming with 0.01% B significantly (p≤0.05) lowered time taken to start germination and time to reach 50% emergence, whereas improved mean emergence time, emergence index, final emergence percentage, number of leaves, dry and fresh weight of root, shoot, and total weight, root length, plant height, chlorophyll contents, number of pods and 100-grain weight, seeds per plant, grain yield per plant, B concentrations in stem and grain, grain protein, carbohydrate and fiber in both cultivars. Boron seed priming proved beneficial under a specific range; however, deficiency (hydropriming) and excess (above 0.01% B) of B were detrimental for mungbean growth and productivity. The cultivar ‘NM-2016’ had significantly (p≤0.05) higher yield due to prominent increase in yield related traits with 0.01% B priming as compared to ‘NM-2011’. In conclusion, B seed priming (0.01% B) seemed a feasible choice for improving mungbean growth, yield related traits and grain-B concentration of mungbean on Yermosols.