Modeling the effects of post-anthesis heat stress on rice phenology

Asseng

et al. 2016

Global Change Biology

Self Cite

124

Higher temperatures caused by future climate change will bring more frequent heat stress events and pose an increasing risk to global wheat production. Crop models have been widely used to simulate future crop productivity but are rarely tested with observed heat stress experimental datasets. Four wheat models (DSSAT-CERES-Wheat, DSSAT-Nwheat, APSIM-Wheat, and WheatGrow) were evaluated with 4 years of environment-controlled phytotron experimental datasets with two wheat cultivars under heat stress at anthesis and grain filling stages. Heat stress at anthesis reduced observed grain numbers per unit area and individual grain size, while heat stress during grain filling mainly decreased the size of the individual grains. The observed impact of heat stress on grain filling duration, total aboveground biomass, grain yield, and grain protein concentration (GPC) varied depending on cultivar and accumulated heat stress. For every unit increase of heat degree days (HDD, degree days over 30 °C), grain filling duration was reduced by 0.30-0.60%, total aboveground biomass was reduced by 0.37-0.43%, and grain yield was reduced by 1.0-1.6%, but GPC was increased by 0.50% for cv Yangmai16 and 0.80% for cv Xumai30. The tested crop simulation models could reproduce some of the observed reductions in grain filling duration, final total aboveground biomass, and grain yield, as well as the observed increase in GPC due to heat stress. Most of the crop models tended to reproduce heat stress impacts better during grain filling than at anthesis. Some of the tested models require improvements in the response to heat stress during grain filling, but all models need improvements in simulating heat stress effects on grain set during anthesis. The observed significant genetic variability in the response of wheat to heat stress needs to be considered through cultivar parameters in future simulation studies.

Section: Discussionmentioning

confidence: 99%

Testing the responses of four wheat crop models to heat stress at anthesis and grain filling

Asseng

et al. 2016

Global Change Biology

Self Cite

124

“…As an alternative, the process-based crop model makes it possible to isolate the effects of different climate factors on grain yield formation [ 38 ]. However, the poor predictions and high systematic errors of process-based crop models under heat stress were reported in many studies [ 20 , 33 , 48 ]. Recently, the process-based sub-model for phenology simulation under heat stress was improved [ 48 ], while more validations are still needed with the field experiment dataset under heat stress [ 49 ].…”

Section: Discussionmentioning

confidence: 99%

Post-Heading Heat Stress in Rice of South China during 1981-2010

et al. 2015

Self Cite

Frequent extreme heat events are the serious threat to rice production, but the historical trend of heat stress associated with phenology shift and its impact on rice yield over a long period are poorly known. Based on the analysis of observed climate and phenology data from 228 stations in South China during 1981-2010, the spatio-temporal variation of post-heading heat stress was investigated among two single-season rice sub-regions in the northern Middle and Lower Reaches of Yangtze River (S-NMLYtz) and Southwest Plateau (S-SWP), and two double-season early rice sub-regions in the southern Middle and Lower Reaches of Yangtze River (DE-SMLYtz) and Southern China (DE-SC). Post-heading heat stress was more severe in DE-SMLYtz, west S-NMLYtz and east S-SWP than elsewhere, because of rice exposure to the hot season during post-heading stage. The spatial variation of post-heading heat stress was greater in single-season rice region than in double-season early rice region due to the greater spatial variation of heading and maturity dates. Post-heading heat stress increased from 1981 to 2010 in most areas, with significant increases in the east of double-season early rice region and west S-SWP. Phenology shift during 1981-2010 mitigated the increasing trends of heat stress in most areas, but not in west S-SWP. Post-heading heat stress played a dominated role in the reduction of rice yield in South China. Grain yield was more sensitive to post-heading heat stress in double-season early rice region than that in single-season rice region. Rice yield decreased by 1.5%, 6.2%, 9.7% and 4.6% in S-NMLYtz, S-SWP, DE-SMLYtz and DE-SC, respectively, because of post-heading heat stress during 1981-2010, although there were some uncertainties. Given the current level and potential increase of post-heading heat stress in South China, the specific adaptation or mitigation strategies are necessary for different sub-regions to stabilize rice production under heat stress.

“…Our results also showed that the correlation between grain yield and GT20 was greater than that between grain yield and average daily temperature during grain filling stage. Just as most studies have reported, GT20 is the key factor to influence rice production by affecting the grain weight and/or grain filling percentage, and after that the temperature has little effect . Relative grain yield could be higher than 1.0 by over 10% when the GT20 was 25.6 ± 0.76 °C (Fig.…”

Section: Discussionmentioning

confidence: 77%

“…Just as most studies have reported, GT20 is the key factor to influence rice production by affecting the grain weight and/or grain filling percentage, and after that the temperature has little effect. 30,55,61 Relative grain yield could be higher than 1.0 by over 10% when the GT20 was 25.6 ± 0.76 ∘ C (Fig. 6).…”

Section: Discussionmentioning

confidence: 92%

Improvement and stabilization of rice production by delaying sowing date in irrigated rice system in central China

Jiang

et al. 2019

J Sci Food Agric

BACKGROUND Climate change has posed great challenges to rice production. Temperature and solar radiation show significant variations in central China. This study aims to analyze the responses of different rice genotypes to the variations of temperature and solar radiation in central China, and to find the way of identifying the optimal sowing date to improve and stabilize rice production. For this end, four rice genotypes (two Indica and two Japonica cultivars) were cultivated at two locations under irrigation conditions in 2 years with six sowing dates. RESULTS We investigated variations of rice grain yield, resource use efficiency, average daily temperature and solar radiation during different phenological stages. Rice grain yield could increase by about 2–17% in central China. Compared with solar radiation, temperature was a more important factor affecting rice grain yield in central China. The grain yield showed great correlation with the means temperature during different phenological stages, especially during the first 20 days after heading (GT20). Besides our results demonstrated that the grain yield displayed slender variations when the GT20 was within 24.9–26.4 °C. However, GT20 was higher than 26.4 °C in most cases, which became more frequent due to climate changes. Analysis of climate change during the last 25 years revealed that the frequency of GT20 within 24.9–26.4 °C was increased by the delay of sowing date. CONCLUSION We propose that delaying sowing date to achieve the optimal GT20 (24.9 °C–26.4 °C) can be an effective strategy to stabilize and improve rice grain yield and resource use efficiency in central China. © 2019 Society of Chemical Industry