ISSN 1392-3196 / e-ISSN 2335-8947
Zemdirbyste-Agriculture, vol. 103, No. 3 (2016), p. 319–326
Possibilities of using image analysis to estimate the nitrogen nutrition status of apple trees
Waldemar TREDER, Krzysztof KLAMKOWSKI, Waldemar KOWALCZYK, Daniel SAS,
Precise timing and rate of nitrogen (N) fertilizer application play a major role for crop yield and quality. Prediction of N requirements is necessary for efficient utilization of nitrogen fertilizers. A user-friendly method for estimating foliar nitrogen concentration, based on an analysis of leaf blade colour, was developed in the study. Apple tree (Malus domestica Borkh.) was used as a model species for the validation of the proposed method. Digital recording of adaxial leaf surface was performed using a flatbed scanner. The acquired images were analysed to obtain average values of basic colours: red, green and blue (RGB). Analyses of the relationships between N concentration in the leaves, leaf greenness indices (determined with SPAD-502 and CCM-200 meters) and RGB colour components were performed. The best fitted models were: a multiple regression model based on RGB primary colour values and a model that included the values of the red and blue colours as well as a parameter describing the age of the leaf. The performed tests showed that the analysis of scanned images provided a more precise determination of leaf nitrogen content in apple tree compared to the measurements conducted with leaf greenness meters.
Key words: chlorophyll content, fertilization, plant nutrition, precision horticulture.
Full text: 103_3_str41.pdf