ISHS Acta Horticulturae 367: VI International Symposium on Pear Growing
RELATIONSHIP BETWEEN CHROMATICITY VALUES AND NITROGEN CONTENT OF PEAR LEAVES |
| Authors: | H. Khemira, D. Sugar, T.L. Righetti |
| Abstract:
Nitrogen (N) fertilizer is one of the most essential nutrients required by fruit trees. It is a mobile element that needs continuous monitoring because trees can become deficient very quickly. The present study is an attempt to find a quick and easy method for growers to estimate leaf N content. The objective was to relate leaf N content (% of dry weight) to Commission Internationale D'Eclairage (CIE) L* a* b* Color Space coordinates measured with a Minolta Chroma Meter CR-200b portable tri-stimulus colorimeter. Two hundred leaves from two pear varieties ‘Bosc’ and ‘Comice’, were evaluated individually for color and N content in two successive years. ‘Comice’ leaves were greener and had a higher N content than ‘Bosc’ leaves. N content was best correlated with b* value (measure of yellowness) and the ratio a*/b* (green/yellow). The strength of this relationship was generally acceptable (R2 values from 0.63 to 0.94) and depended on the variety and year of study. Although a usable relationship can be developed for a given variety in a given year, it was not possible to develop predictive equations that could be generally applied. | |
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