Spatial And Temporal Distribution Of Rice Yield And Growth Period Parameters In Main Rice Planting Regions Of China

Rice is one of the most important food crops in China.The temporal and spatial distribution of growth period,yield and yield structure of different rice varieties in the main rice planting areas in China varies greatly,and there are significant seasonal and regional variations.However,a large-scale and systematic research in this field has not been reported yet.Therefore,based on 1981-2011 year historical meteorological data and the rice planting,the spatial and temporal distribution of growth period,growth phenological parameters,yield and yield components in main rice producing areas of different ages in China were studied,and the different regional climate factor on the growth period of rice,yield and yield component were quantified.The contribution of yield components to yield was quantified by path analysis.This study will provide support for productivity prediction and evaluation,production management strategy formulation and food security in major rice producing areas in China.Using the dataset from 231 stations in main rice producing areas in China during1981-2011,and the growth phenological parameters of Rice Grow and Ceres-Rice models,including basic Intrinsic Earliness,Photoperiod Sensitivity,Temperature Sensitivity,Optimum Temperature,Basic Filling Factor in Rice Grow,and thermal time required TO complete the basic vegetative growth phase(P1),thermal time required from panicle differentiation to panicle production(P2R),the photoperiod and day length of the most flourishing period of crop growth(P2O)in CERES-Rice,and the historical yield and yield components(panicles number,number of spikelet per panicle,seed setting rate,1000-grain weight)were used as indexes.The spatial and temporal distribution of characteristic parameters of rice varieties in main rice producing areas of China in different ages were studied.The results showed that the growth duration of single rice decreased first and then increased from northeast to southwest.The period from sowing to flowering of early rice increased gradually from northeast to southwest,and the period from flowering to maturity and the whole growth period increased gradually from north to south.The period from sowing to flowering stage of late rice decreased first and then increased from northeast to southwest,while the period from flowering to maturity and whole growth period showed an opposite trend: increased first and then decreased from northeast to southwest.The growth period in the single-cropping rice area were significantly higher than those in the early and late rice area.IE and P1 of early rice were the largest,followed by late rice and single rice.The TS and P2 R of early rice were higher than that of late rice,but the PS and P2 O of early rice were lower than that of late rice.The BFF of single rice was the highest,followed by that of late rice and early rice.For hybrid rice,indica rice and japonica rice varieties,the growth period of hybrid rice was the longest,followed by japonica rice and indica rice.Under the influence of climate warming,the length of rice growth period declined.The IE and P1 of indica were higher than that of japonica,the TS and P2 R of indica were higher than that of japonica,but the TS and P2 O of japonica were higher than that in indica,and the BFF of japonica were higher than that of indica.The yield and yield component of single rice,early rice and late rice in China had significant spatial and temporal characteristic.In terms of spatial distribution,the yield and seed setting rate of single rice in northeast China were significantly higher than those of other regions,the yield of double rice in south China was lower than that of single rice region,and the yield of early rice was higher than that of late rice.The 1000-grain weight in the southern single-cropping rice region was the largest,followed by the double-cropping rice region,and the single rice in the northeast was the smallest.The single rice in northeast China was the largest,followed by double rice,and the single rice in South China was the least.On the whole,the number of panicles per unit area was the largest in the southern single-cropping rice region,followed by the southern double-cropping rice region and the smallest in the northeastern single-cropping rice region.The yield and 1000-grain weight of hybrid rice were the highest,followed by japonica rice and indica rice.The1000-grain weight,seed setting rate and yield of rice in China all showed an upward trend from 1980 s to 2000 s.The effects of climate factors on rice growth period,yield and yield component were quantified by multiple regression using the data from each station.The direct effects of yield components on rice yield were quantified by path analysis.For single rice,the results showed that the yield was significantly correlated with Growth Degree Day(GDD).Seed-setting rate was significantly correlated with rainfall(RAIN)and Solar Radiation(SRAD).The 1000-grain weight was not related to meteorological factors.The spike number per unit area was significantly correlated with RAIN and GDD.For early rice,the yield was significantly correlated with RAIN,Heat Degree Day(HDD),Cold Degree Day(CDD)and GDD.Seed setting rate was significantly correlated with HDD and GDD.1000-grain weight was significantly correlated with RAIN.The panicle number per unit area of early rice was significantly correlated with SRAD.For late rice,the yield was correlated with SRAD and HDD.Seed setting rate was related to HDD and CDD.1000-grain weight was correlated with SRAD,HDD and CDD.The spike number per unit area was significantly correlated with RAIN and GDD.The contribution rate of grain number per panicle to yield in single cropping rice area was higher,reaching 50%,number of panicles,and 1000-grain weight was the minimum.In the 1980 s,1990s and 2000 s,the contribution rate of grain number per panicle decreased gradually,while the number of panicles and 1000-grain weight increased year by year in single-cropping rice area.The contribution rate of grain number per panicle to yield in double cropping rice area was the highest,which reached about 40%,followed by 1000-grain weight and the lowest panicle number.The contribution of 1000-grain weight increased first and then decreased,while the contribution of panicle number and grain number per panicle decreased first and then increased in double cropping early rice area.The contribution rate of grain number per ear had little change in the late rice area with double cropping,but the contribution rate of grain number per ear decreased gradually,and the 1000-grain weight increased gradually.