The nutrient inversion model of apple leaves was established by spectral analysis technology to provide technical support for the fine management of apple trees.In Shuangquan Town,Changqing District,Jinan City,Shandon...The nutrient inversion model of apple leaves was established by spectral analysis technology to provide technical support for the fine management of apple trees.In Shuangquan Town,Changqing District,Jinan City,Shandong Province,the Fuji apple trees with stopping period of spring shoots were taken as research objects.The spectral reflectance and nitrogen content of apple leaves were measured by ASD Field Spec 4 portable ground object spectrometer.Analyzed the correlation between leaf nitrogen content and spectral reflectance.The sensitive wavelengths with high correlation coefficient were select by fractional differential algorithm,and the optimal vegetation index was constructed and screened out.Partial Least Square Regression(PLSR),Support Vector Machine(SVM)and Random Forests(RF)method were used to construct an inversion model of leaf nitrogen content.The results show that the RF model based on fractional differential second-order treatment is the best inversion model for the nitrogen content of leaves during stopping period of spring shoots.The modeling accuracy determination coefficient R2 reached 0.891,RMSE was 0.0841,and RPD was 2.1396.The determination coefficient R2 of the fitting results of the verification set was 0.617,RMSE was 0.1251,and RPD was 1.7105.The inversion model established by RF method is effective in monitoring the nitrogen content in apple leaves,which provides a theoretical basis for monitoring the growth of apple by hyperspectral technology.展开更多
The experiment was mainly used to study the effect of insect-proof net mulching cultivation technology on the temperature and humidity of the greenhouse and the spring shoot growth of citrus Shatangju. The results sho...The experiment was mainly used to study the effect of insect-proof net mulching cultivation technology on the temperature and humidity of the greenhouse and the spring shoot growth of citrus Shatangju. The results showed that the 40-mesh translucent insect-proof net had a positive effect on the spring shoot growth of Shatangju in the spring from January to April. In the meantime,according to the change of the temperature and humidity inside and outside the insect-proof net and the change of quantity of Aleyrodidae,Tetranychidae and Phyllocnisidae,it was found that the role of insect-proof net in enhancing the spring shoot growth of Shatangju was possibly achieved by the regulation of citrus pests and the temperature and humidity inside the net.展开更多
基金This paper was supported by the National Natural Science Foundation of China(41671346)the National Key Research and Development Program of China(2017YFE0122500)+1 种基金Shandong Major Scientific and Technological Innovation Project(2018CXGC0209)the Taishan Scholar Assistance Program from Shandong Provincial Government,Funds of Shandong“Double Tops”Program(SYL2017XTTD02).
文摘The nutrient inversion model of apple leaves was established by spectral analysis technology to provide technical support for the fine management of apple trees.In Shuangquan Town,Changqing District,Jinan City,Shandong Province,the Fuji apple trees with stopping period of spring shoots were taken as research objects.The spectral reflectance and nitrogen content of apple leaves were measured by ASD Field Spec 4 portable ground object spectrometer.Analyzed the correlation between leaf nitrogen content and spectral reflectance.The sensitive wavelengths with high correlation coefficient were select by fractional differential algorithm,and the optimal vegetation index was constructed and screened out.Partial Least Square Regression(PLSR),Support Vector Machine(SVM)and Random Forests(RF)method were used to construct an inversion model of leaf nitrogen content.The results show that the RF model based on fractional differential second-order treatment is the best inversion model for the nitrogen content of leaves during stopping period of spring shoots.The modeling accuracy determination coefficient R2 reached 0.891,RMSE was 0.0841,and RPD was 2.1396.The determination coefficient R2 of the fitting results of the verification set was 0.617,RMSE was 0.1251,and RPD was 1.7105.The inversion model established by RF method is effective in monitoring the nitrogen content in apple leaves,which provides a theoretical basis for monitoring the growth of apple by hyperspectral technology.
基金Supported by Special Construction Project of Modern Agriculture(Citrus)Industry Technology System(cars-27)
文摘The experiment was mainly used to study the effect of insect-proof net mulching cultivation technology on the temperature and humidity of the greenhouse and the spring shoot growth of citrus Shatangju. The results showed that the 40-mesh translucent insect-proof net had a positive effect on the spring shoot growth of Shatangju in the spring from January to April. In the meantime,according to the change of the temperature and humidity inside and outside the insect-proof net and the change of quantity of Aleyrodidae,Tetranychidae and Phyllocnisidae,it was found that the role of insect-proof net in enhancing the spring shoot growth of Shatangju was possibly achieved by the regulation of citrus pests and the temperature and humidity inside the net.