Improving Winter Rice Establishment through Seed Priming

Abstract

The primary source of food production and national security in Bangladesh is winter (locally known as ‘boro’) rice. Floods, droughts, high heat and cold, and salinity strains are just a few of the natural calamities and stresses that Bangladeshi agriculture faces almost every year. Rice is substantially less resilient to cold stress because it is a tropical crop. A beneficial agronomic method for boosting seed performance is seed priming, which raises the germination levels, vigour and the consistency of seedlings. It involves treating seeds early before sowing, which enhances the seed's metabolic activities, leading to expedited and enhanced germination. This strategy has become significant for strengthening crop establishment and flourishing, especially in adverse environments. The current investigation was conducted to develop a suitable seed priming technique for successfully producing winter rice under cold or salinity stress. The investigation was performed utilising a Completely Randomised Design (CRD) with four replications at the Bangladesh Institute of Nuclear Agriculture (BINA), Mymensingh, Bangladesh, in the Agronomy Division. The study spanned from November to December 2018. The presented research explored the impacts of seed priming substances on three different winter varieties of rice: i) BRRI dhan29, ii) BRRI dhan36, and iii) BRRI dhan67. Eight seed priming treatments were applied, namely i) Control (without priming), ii) Hydro priming (24 hrs), iii) 150 ppm PEG 8000, iv) 15000 ppm ZnSO4, v) 15000 ppm MnSO4, vi) 20000 ppm KCl, vii) 16000 ppm NaCl and viii) 22000 ppm CaCl2. Results suggested that this technique positively impacts germination rate, vigour index and seedlings' growth. ZnSO4, KCl, and CaCl2 turned out to be among the best priming agents, while NaCl and PEG provided no significant improvement compared to the control for seedling vigour and germination rate. Priming with ZnSO4, KCl, and CaCl2 resulted in the greater final germination percentages across all varieties, with BRRI dhan67 showing superior performance under these treatments. Similarly, priming with KCl resulted in 85.25%, 84%, and 92.5% final germination, while CaCl2 produced 90%, 89.25%, and 92.5% for these varieties. Mean germination time was strongly correlated with time to 50% germination (r= 0.78***). These findings suggest that the effectiveness of specific priming agents, particularly ZnSO4, KCl, and CaCl2, enhances seed performance and early seedling development, offering a promising strategy for optimising winter rice cultivation.