Evaluation Of Some Physiological Parameters Of Winter Wheat Leaves Using Digital Image Processing

Based on the pictures of leaves separated from the plants of wheat captured by digital camera, digital image processing and the statistical analysis, combing with normally calculations of physiological parameters and nutrients assay of the plants, the experiment was carried out at the experiment station of Agricultural University of HeBei during 2002 to 2004, with a purpose to evaluate the feasibility to predict the physiological parameters by using digital image processing, and to get useful color parameters. The results of this research are as follows:1. The flag leaves of 9 wheat varieties used in this experiment were first photographed, and then the chlorophyll contents were measured. The results indicated that the average of R, G and B were 140.88,144.99,137.31 and the average of r, g and b were 0.3328,0.3426, 0.3245, respectively. That indicates that the flag leaves reflect more green lights than red and blue lights, while absorb less than red and blue lights.2. In the middle of filling stage, the chlorophyll contents of flag leaves could be evaluated non-damaged using color parameters. There were significant correlations between the G/R, R/L and the chlorophyll contents of flag leaves. On May 24, the color parameters to predict the chlorophyll contents were L, R, G, B, R/L, G/R, I, H and rate of RGB; on May 27, they were g, R/L, G/L, G/R and S.3. The correlations between the photosynthetic parameters and color parameters were analyzed. The results indicated that there were significant correlations between the photosynthetic rates, transpiration rates, stomata conductances of flag leaves and the second leaves from top and S. So S could be used to evaluate non-damaged above parameters in the middle stage of filling. In addition, there were significant correlations between G/B and intercellular CO2 concentrations of flag leaves and the second leaves from top in die middle stage of filling.4. The nitrogen, contents of the second leaves from top at different time points had no significant correlation with color parameters. But at some growth stages the nitrogen contents of flag leaves (22/4) could be measured non-damaged by using S; the nitrogen contents of the second leaves (15/4) from top could be measured by using b, B/L and S; the nitrogen contents of the fourth leaves from top (15/4) could be measured by using R, the...