Application of Agronomic Model in Yield Dynamic Prediction of Winter Wheat

Cheng Lin; Liu Ronghua

doi:10.16765/j.cnki.1673-7148.2017.02.004

Abstract：According to the agronomic principle that the theoretic yield of winter wheat is the multiplication of productive tiller in unit area,kernels per spike and thousand seed weight,suitability indexes models of air temperature,sunshine hour,precipitation and soil water during the growing season of winter wheat were used.The 5 representative stations were chosen in Henan province,and by taking advantage of meteorology elements in period of ten days in 1995-2013,suitable indexes sequence of air temperature,sunshine hour,precipitation and soil water were calculated,and then,dynamic forecasting models for the variation rate or departure of the yield elements were established respectively.The results indicated that,although productive tiller was not obviously related to meteorological conditions,the variation of plant spike number had better correlation coefficients with temperature and water suitable index,and the departure of thousand seed weight was related to soil moisture suitable index obviously,however,the correlation between kernel number and suitable index of meteorological elements was small.Except for the forecasting model of kernel number variation,the forecasting models for plant spike number variation and thousand seed weight departure all passed the significance test.The models could forecast the yield elements step by ten days from April 1,and for the 5 representative stations,the average accuracy rate of back substitution test for plant spike number,kernels number per spike and thousand seed weight was 80.4％,88.5 ％ and 94.0％ respectively,and after the first ten day of May,the average accurate rate was 93.3％ for the theoretical yield forecasting.For the extrapolation test with data of 2014,the accurate rate of kernel number and thousand seed weight was higher than 92.0％.So by the method of combination of suitability indexes of meteorological elements with agronomic model,dynamic forecasting of final yield could be feasible,and the accuracy could satisfy the demand of operation and service.However,the accurate rate was relatively low for the bumper or poor harvest trending prediction by this method.