Critical weather limits for paddy rice under diverse ecosystems of India

Abstract

Rice yields are largely influenced by variability in weather. Here, we demonstrate the effect of weather variables viz., maximum and minimum temperatures, rainfall, morning and evening relative humidity, bright sunshine hours on the yield of rice cv. Swarna, grown across five rice ecologies of India through field experiments during kharif (wet) season (Jun-Sept.). Critical thresholds of weather elements were identified for achieving above average, average and below average yield for each ecology. The investigation could determine how different weather elements individually and collectively affect rice yield in different rice ecosystems of India. While a sudden increase in minimum temperature by 8-10 °C (> 30 °C) during reproductive period resulted in 40-50 per cent yield reduction at Mohanpur, a sudden decrease (< 20 °C) caused yield decline at Dapoli. The higher yields may be attributed to a significant difference in bright sunshine hours between reproductive phases of above-average and below-average yield years (ranging from 2.8 to 7.8 hours during P5 stages and 1.7 to 5.1 during P4 stages). Rice cultivar Swarna performed differently at various sowing dates in a location as well as across locations (6650 kg ha-1 at Dapoli to 1101 kg ha-1 at Samastipur). It was also found that across all locations, the above average yield could be associated with higher range of maximum temperature compared to that of below average yield. Principal component analysis explained 77 per cent of cumulative variance among the variables at first growth stage, whereas 70 per cent at second growth stage followed by 74 per cent and 66 per cent at subsequent growth stages. We found that coastal locations, in contrast to inland ones, could maximize the yield potential of the cultivar Swarna, due to the longer duration of days between panicle initiation to physiological maturity. We anticipate that the location-specific thresholds of weather factors will encourage rice production techniques that are climate resilient.

Rainfall variability and its effect on kharif rice yield in Manipur: a multi-decadal analysis

“…Similarly, for August, the corresponding figure is 0.04%, and a similar value was also observed for rainfall in September. Adequate and timely June rainfall is essential for proper germination, transplanting, and early growth stages of the rice crop; August rains help rice in the crucial reproduction stage of its crop cycle (Bal et al, 2023). As shown above, the sensitivity of rice yield to June and August rainfall is critical due to the declining trend in monsoon rainfall observed in the region (Saha and Ghosh, 2019).…”

Climate Science, Solutions and Services for Net Zero, Climate-Resilient Food Systems

“…The Kobayashi et al (2010) concluded that higher air temperature and incident radiation tend to advance anthesis in rice. Thus, delayed transplanting forced the crop to pass through a relatively lower temperature regime during its reproductive phase (Bal et al, 2023). They also reported significant variation in rice yield in response to weather variabilities during different growth phases of the crop under the diverse ecosystems of India.…”

Managing climatic risks in rice–wheat cropping system for enhanced productivity in middle Gangetic plains of India

“…The month-wise rainfall distribution pattern is given in Figure 2. May is the warmest summer month of the year with a daily maximum temperature of 37-41°C, while the coldest winter month is January with a daily minimum temperature of 5-8°C in January (Bal et al, 2023). Although December, January, and February are the main winter months, temperature decreases significantly from November.…”

“…The 2010) concluded that higher air temperature and incident radiation tend to advance anthesis in rice. Thus, delayed transplanting forced the crop to pass through a relatively lower temperature regime during its reproductive phase (Bal et al, 2023). They also reported significant variation in rice yield in response to weather variabilities during different growth phases of the crop under the diverse ecosystems of India.…”