数字图像技术在黄瓜氮素营养诊断上的应用研究

Diagnosis of N Status of Cucumber Using Digital Image Processing Technique

试验设计了6种氮素水平处理温室黄瓜,利用数码相机获取黄瓜冠层图像,分析了不同供氮水平下黄瓜冠层图像参数与施氮量、土壤无机氮(Nmin)和植株氮素营养指标之间的关系。结果表明:黄瓜冠层图像G/(R+G+B)为诊断黄瓜结果期氮素营养状况的适宜数字化参数。建立了评价黄瓜结果期氮素营养丰缺的冠层图像数字化指标G/(R+G+B)的量值标准和氮肥推荐标准。

The digital pictures of the winter wheat canopy were obtained with a Canon digital camera in 2004. The G/（ R ＋ G ＋ B） ratio from the cucumber canopy was compared, to the Nmin concentration in the soil, to the sap nitrate concentration in petiole, to the SPAD readings of leaves, and to the total N con-centration. The results show significant inverse linear correlation between the G/（ R ＋ G ＋ B） ratio and Nmin in soil, sap nitrate concentration in petiole, total N, and SPAD readings at bearing fruit stage. G/（R ＋ G ＋ B） can be considered as an important indictor of N status in cucumber. Optimum N rate at top-dress was determined in growth stages.