Impacts of climate variability on rice yield and diseases in coastal Bangladesh

Climate change has added a new dimension to the unpredictability of rice yields. Climate variability and change directly impact rice yields through fluctuations in climatic variables. Indirectly, changes in temperature, rainfall, and humidity may facilitate the spread of pests and diseases, further compromising yields. Despite various studies that have focused on the impact of climate variability on rice yield and diseases, there is a scarcity of region-specific and integrative research that applies both systematic review and climate-crop data analysis in coastal Bangladesh.The current study investigated the impact of climate variability on rice yields and disease prevalence in coastal Bangladesh through a systematic literature review and analysis of 38 years of climate and crop data. Data obtained from systematic reviews were analyzed using thematic content analysis. To assess trends in climate variables, we used Mann-Kendall tests, and we used quadratic polynomial regression to evaluate the influence of climatic variables on rice yields. Logit models were used to determine which climate variables were most influential on disease occurrence in rice. In the analyzed literature, 61% of studies reported a negative effect of climate variability on rice yields, while 18% reported a positive effect. The historical climate data showed significant increases in temperature (0.04°C/year) and humidity (0.14%/year). Despite a short-term positive effect of rising temperature and humidity on rice yields, the long-term cumulative effect over the 38 years was negative. Regarding rice diseases, sheath blight increased more rapidly than blast and bacterial blight due to rising temperature and humidity. Our study concludes that sustainable rice production requires farm-level adaptation strategies. It is recommended that the agricultural extension department should provide training to farmers on changes in climatic variables and their impact on rice yields and diseases, use of climate information services and climate-smart rice production to facilitate adaptation to climate change.