Bangladesh grapples with significant hurdles in sustaining its rice production amidst frequent heatwaves and droughts, exacerbated by the absence of heat-tolerant rice strains and the underperformance of less popular drought-resistant varieties.

Over the years, the Bangladesh Rice Research Institute, a state-owned entity, has developed 115 rice strains, primarily concentrating on enhancing yields, seemingly operating under favorable climatic conditions.

These advancements have propelled Bangladesh’s rice output to increase nearly three-and-a-half times since 1971, marking a noteworthy accomplishment crucial for nourishing the nation’s vast populace.

In 2023, Bangladesh yielded approximately 4 crore tonnes of rice, a notable rise from 3.1 crore tonnes recorded in 2010.

Professor ASM Golam Hafeez, an expert in agricultural economics and rural sociology at Bangladesh Agricultural University, emphasizes the looming threat to food and nutrition security due to the absence of new crop varieties capable of withstanding heightened temperatures and droughts.

He warns that without such varieties, food inflation will remain unchecked, as heat reduces production while increasing labor and irrigation costs.

Bangladesh experienced its longest-ever heatwave, spanning 37 days from the end of March this year, with temperatures frequently surpassing 40°C across central and northern regions, the primary rice-producing areas.

Last year witnessed the second-longest heatwave, lasting 23 days, accompanied by record or near-record temperatures.

A heatwave, defined as temperatures reaching or exceeding 36°C, poses a severe risk to living beings. Currently, Bangladesh is in the midst of another heatwave, which commenced five days ago.

On Friday, Chuadanga recorded the country’s highest maximum temperature of 39.6°C, prompting a fresh two-day heat alert from the Bangladesh Meteorological Department.

Officials at the Bangladesh Rice Research Institute (BRRI) note that the country’s rice varieties perform optimally within the temperature range of 20°C to 30°C.

However, temperatures exceeding 33°C during the flowering stage can induce sterility in paddies, leading to reduced rice production.

Khandakar Iftekharuddaula, head of the plant breeding division at BRRI, suggests that Bangladesh is on the verge of developing its first-ever heat-tolerant rice variety, although he estimates it may take an additional two years to achieve this milestone.

Despite the urgency for drought-tolerant varieties, only eight have been released since 2011, with minimal popularity among farmers who prefer imported Indian varieties or rely on frequent irrigation.

Rising temperatures have disrupted Bangladesh’s traditional rice cultivation calendar, particularly impacting the three major types: boro, aus, and aman.

Boro, comprising over half of the total rice production, faces challenges due to its cultivation in winter and harvest during the onset of summer heat.

Aus, typically planted between March and May and harvested between July and August, has seen a reduction in cultivation area but an increase in production due to high-yielding varieties.

Aman, cultivated in two periods between March and April and June and July, faces challenges from excessive rain and rising temperatures, affecting its harvest between October and December.

Efforts to mitigate these challenges include the cultivation of drought-tolerant varieties such as BRRI 56, BRRI-66, and BRRI-71 for Aman rice.

However, adoption rates remain low, primarily due to farmers’ access to higher-performing Indian varieties.

High temperatures and droughts affect rice plants at every growth stage, diverting energy from grain formation to cooling mechanisms.

The drying of pollen-sticking substances during pollination exacerbates these challenges.

The BRRI advises farmers to maintain adequate water depth in rice fields during heatwaves.

Recent studies indicate an increase in heatwave frequency and overall temperature across Bangladesh since 1980, with record-breaking temperatures recorded in various regions, underscoring the urgent need for adaptive measures in agriculture.