Study On The Effect Of SPAD Value On Wheat Yield During Wheat Filling

Wheat(Triticum aestivum l.)is not only one of the main grain crops in huang-huai-hai region,but also one of the main grain crops in China.The high and stable yield of wheat is of great significance to China’s food security and social stability.In this study,three factors and two levels were used to arrange the experimental treatment,the diurnal variation,growth season variation,yield and yield characters of SPAD values of the upper trifoliate(flag leaf,inverted second leaf and inverted third leaf)of wheat were investigated at the grouting stage,and the correlation between SPAD value and yield and yield traits was analyzed.It is expected to provide theoretical basis for the cultivation and management of wheat and the better realization of yield increase and high yield,as well as theoretical support for the exploration of the geographical spatial distribution of wheat in China,and lay a foundation for chlorophyll monitoring and rapid nutrition diagnosis of field crops.The following are the main research conclusions of this paper:(1)Through the analysis of the daily variation rule of SPAD value of wheat functional leaves under different treatments during the filling period,The chlorophyll content of the functional leaves at the three positions generally showed a decreasing trend from 6:00 to 18:00.In addition,according to the time when the SPAD values of the three position functional blades appeared the crest,the flag leaves were most affected by light and temperature,followed by the inverted two leaves,and finally the inverted three leaves.(2)Through the analysis of the growth season variation rule of SPAD value of wheat functional leaves under different treatments during the grouting period,The chlorophyll content of the three functional leaves showed a decreasing trend at the grouting stage.Meanwhile,over time,the SPAD values of the functional leaves in the three positions of wheat tend to be in the order that the flag leaf > inverts the two leaves > inverts the three leaves.And in the same period not equally between,same as the difference between different periods significant.(3)According to the analysis of yield and yield shape,Under no-tillage treatment,the amount of nitrogen applied to corn straw returning to the field was 280 kg,and the yield was the highest when the corn straw was returned to the field,while the yield was the lowest when the corn straw was not returned to the field,the amount of nitrogen applied was 210 kg,and the yield was the lowest when the corn straw was not returnedto the field.Under the treatment of constant tillage,the amount of nitrogen applied to the corn straw was 280 kg without returning to the field,and the yield was the highest when the corn straw was returned to the field,and the yield was the lowest when the corn straw was returned to the field,and the amount of nitrogen applied was 280 kg.There were differences in plant height,spike length,number of sterile spikelets,number of grains per spike and 1000-grain weight among different combinations of the sample plots,but the effect on the number of bearing spikelets was not significant.The yield of sample plot 1 was different from that of the other 7 plots,but the difference between the other 7 plots was not significant.(4)According to the correlation analysis between SPAD value and yield traits of wheat at the grouting stage,There was a significant positive correlation between wheat SPAD value and yield(P < 0.05),and a very significant positive correlation between SPAD value and thousand seed weight(P < 0.01).(5)The management measures of sample plot 1 can increase the SPAD value and yield of wheat at the same time,The optimal treatment under the experimental conditions that the corn straw was returned to the field,and the amount of nitrogen was280 kg...