Drought and limited availability of water serve as the serious limitation for rice production in rainfed ecosystems. Among the major rainfed rice-cultivating areas, states of eastern India occupy one of the largest drought-prone ecologies in the world. Cultivating drought tolerant rice varieties can serve as the most coherent approach to ensure food security in these areas. International Rice Research Institute (IRRI), along with its national collaborators, has developed drought tolerant rice varieties possessing high yield along with desirable grain quality. One such conventionally bred line, IR74371-70-1-1, has been released with different names in the different countries: in India as Sahbhagi Dhan, in Nepal as Sukha Dhan 3, and in Bangladesh as BRRI Dhan 56. This indicates the suitability of this line to show better performance across the wide range of environments. Sahbhagi Dhan is a short duration variety that has genetic drought tolerance and is more efficient at extracting available moisture from the soil. During drought years, farmers cultivating Sahbhagi Dhan obtained the yield advantage of 0.8 to 1.6 t ha⁻¹ over currently grown long duration as well as traditional varieties. In 2012, when the paddy crop was hit by drought, Sahbhagi Dhan revealed the yield advantage of more than a t ha⁻¹, which reduced to 0.78 and 0.56 t ha⁻¹ during non-drought years of 2013 and 2014, respectively. Data taken from head to head trials during 2017 showed that Sahbhagi Dhan exhibited better performance over the existing rice varieties grown by farmers even under non-drought conditions. The important feature of Sahbhagi Dhan is its evident impact under drought and no yield penalty under favorable conditions over the counterfactual varieties of the same duration. Along with better yield under drought, the important advantage of Sahbhagi Dhan is the short maturity duration of this variety. This allows the farmers to advance the succeeding crop and creates an opportunity for accommodating an additional crop under favorable rainfed ecology, thereby enhancing the cropping intensity. Since the majority of the farmers living in drought prone ecologies are socio-economically under privileged, Sahbhagi Dhan, along with other drought tolerant varieties, can serve as one of the most viable and deliverable technologies for eradicating poverty from these ecologies dependent on rainfed rice.

• Genetic gain for rice grain yield for International Rice Research Institute drought breeding program was estimated. • Positive trend of 0.68 %, 0.87 %, 1.9 % under irrigated control, moderate and severe drought achieved. • Superiority of new rice varieties over currently grown demonstrated on farmers’ fields. • International Rice Research Institute developed rice varieties can protect farmers from crop losses under drought conditions.

Adoption of the right rice variety and water-saving irrigation method could reduce greenhouse gas (GHG) emissions in lowland rice cultivation. A study was conducted at the research farm of Bangladesh Agricultural University, Mymensingh, Bangladesh, in 2019 during the Boro (dry) season to determine the impacts of different rice varieties (BRRI dhan29, BRRI dhan47, BRRI dhan69, Binadhan-8, Binadhan-10, and Binadhan-17) on methane (CH₄) emissions under two irrigation methods, i.e., alternate wetting and drying (AWD) and continuous flooding (CF). The treatments were laid out in a split-plot design, considering water regime as the main plots and rice variety as the sub-plots. The emission rates of CH₄ were determined by collecting air samples using the closed chamber technique and measuring the concentrations using a gas chromatograph. CH₄ emission rates varied with the growth and development of the rice varieties. The lowest cumulative CH₄ emission rate was observed in Binadhan-17, particularly under AWD irrigation. Across the rice varieties, AWD irrigation significantly reduced the cumulative CH₄ emissions by about 35% compared with CF. No significant variation in rice yield was observed between AWD (5.38 t ha⁻¹) and CF (5.16 t ha⁻¹). This study suggests that the cultivation of Binadhan-17 under AWD irrigation could be effective at reducing the carbon footprint of lowland rice fields.

Rice is a major crop in Bangladesh that supports both food security and livelihoods. However, a need remains for improved productivity and adaptation to the risks associated with climate change. To accomplish this, the increased adoption of climate-resilient and high-yielding rice varieties can be beneficial. Therefore, we conducted a study in Bangladesh over three consecutive years: 2016, 2017, and 2018. The scope of the study included the major cropping season (wet), Aman. The yield advantages of climate-resilient rice varieties were evaluated and compared with those of the varieties popular with farmers. We included new stress-tolerant varieties, such as submergence-tolerant rice (BRRI dhan51 and BRRI dhan52) and drought-tolerant rice (BRRI dhan56 and BRRI dhan71), along with farmer-chosen controls, in the study. We conducted the evaluation through on-farm trials to compare the varieties in both submergence- and drought-affected environments. The seasonal trials provided measured results of yield advantages. The participating farmers were also studied over the three-year-period to capture their varietal adoption rates. We calculated both the location estimated yield advantages (LEYA) and the location observed yield advantages (LOYA). The results revealed that, under non-stress conditions, the grain yields of climate-resilient varieties were either statistically similar to or higher than those of the farmer-chosen controls. Our study also revealed a year-to-year progressive adoption rate for the introduced varieties. The study suggests that the wide-scale introduction and popularization of climate-resilient varieties can ensure higher productivity and climate risk adaptation. The close similarity between LOYA and LEYA indicated that the observational and experiential conclusions of the host farmers were similar to the scientific performance of the varieties. We also found that comparison performed through on-farm trials was a critical method for enhancing experiential learning and obtaining an accurate estimation of yield advantages.