Yield Gap Analysis between Dry and Wet Season Rice Crop Grown under High‐Yielding Management Conditions

Abstract

Rice (Oryza sativa L.) grain yield highly varies depending on cropping seasons under the tropical irrigated conditions. Th is study aimed to (i) compare the grain yield of rice in dry season (DS) and wet season (WS) and (ii) determine climatic and physiological factors critical to the yield gap between DS and WS. Six genotypes, two each for indica inbred, indica/indica F 1 hybrid, and the second-generation new plant type, were grown in DS and WS of 2003 and 2004. Signifi cantly higher grain yields were achieved in DS than in WS by 94% for 2003 and 35% for 2004. Mean daily radiation was higher in DS than WS, particularly during grain fi lling stage than before fl owering. Th e greater radiation during ripening in DS contributed to the higher grain yield. Major difference in biomass production between DS and WS occurred aft er fl owering. Greater biomass accumulation from fl owering to physiological maturity was associated with higher grain yield in DS than in WS, but not translocation of biomass accumulated before fl owering to grains. Higher grain yield in DS was partly the result of greater spikelets due to higher spikelet production effi ciency per unit biomass at fl owering. Aboveground total biomass at physiological maturity was a crucial physiological factor to the yield gap between DS and WS. Daily mean radiation and biomass accumulation during ripening, and sink production effi ciency per unit biomass were critical factors to the yield gap of rice between DS and WS under the high-yielding tropical irrigated conditions.Abbreviations: DS, dry season; WS, wet season; Wr, biomass accumulated during ripening; T, translocation of the biomass at fl owering to rice grains.

Responses of Single Cropping Rice Yields to Climate Change in Sichuan Province, China

“…This result was consistent with the finding in some other researches [7,17,18], which suggesting that temperature was above the optimal temperature of rice production and increasing temperature might reduce yield. However, T avg during RGS 2 and RGS 3 were significantly positively related to rice yield in some regions, which was consistent with other studies [12,19]. This result indicated that present T avg might be in the optimal temperature range and increasing temperature might increase yield.…”

Effects of a Multistrain Biofertilizer and Phosphorus Rates on Nutrition and Grain Yield of Paddy Rice on a Sandy Soil in Southern Vietnam

“…Of the climatic factors responsible for rice yield differences investigated by Yu et al (2001), the number of hours of sunshine during the tillering stage and the heading to milk stage particularly affected the yield. Such an effect results in higher grain yields in the tropics from dry season crops compared to wet season crops because of higher irradiance (Yang et al, 2008). Significant interactions between irradiance and nutrient availability occur (Evans and De Datta, 1978).…”

Assessing the relative importance of climate variables to rice yield variation using support vector machines

“…For example, Liu et al (2014) found that daily temperature range and sunshine hours had higher direct and indirect effects on rice yield variation using path analysis. Other studies also reported that sunshine hours had a positive correlation with rice yields, since the increasing of sunshine hours could accelerate photosynthesis and hence increase crop yield (Evans 1993;Yang et al 2008;Dobermann et al 2000;Zhang et al 2010). Both rainfall and rainy days have lower influence on rice yield variation than sunshine hours and daily temperature range.…”