Abstract: Through the observation and research of whole phenological stage of summer maize in agrometeorological station in Hebi city, Henan province and by means of field monitoring image capture device to collect different maize image data and analyzing image feature of group images as well as parameters with a variety of colors, the identification of the main phenological stage can be attained. For different phenological stage, RGB color space to extract green pixel value and HSL color space to extract yellow pixel value are used to determine the proportion of developmental period. For the weed effect on the extraction image color, proposed using small area elimination algorithm based on region labeling to eliminate weed impact in pictures. For wet soil on the extraction of the interference of the yellow pixel value in pictures, proposed combining S value of HSL color space to eliminate the color of wet soil. After comparison with the manual observation, the results showed that it is available to identify maize developmental period by using color parameters. The correct recognition rate reaches 94.26%.

Key words: font-family: "Times New Roman", mso-bidi-font-size: 12.0pt, mso-hansi-font-family: 宋体, mso-bidi-font-family: 宋体, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA, mso-fareast-font-family: 宋体">Maize, Phenological stage, Image recognition, Color feature