Journalartikel

Jahr der Veröffentlichung: 2001

Seiten: 445-450

Zeitschrift: Journal of Plant Nutrition and Soil Science

Bandnummer: 164

Heftnummer: 4

ISSN: 1436-8730

Verlag: Wiley-VCH Verlag

Abstract: 
Mineral deficiencies can seriously reduce crop yield and economic returns to farmers. Reflectance measurements may provide inexpensive and fast estimates of the mineral status of plants. This study was conducted to examine specific changes of leaf reflectance due to nutrient deficiencies. During the 1998 and 1999 growing seasons leaf scans of N-, P-, Mg-, and Fe-deficient corn plants were performed with a digital LEICA S1 PRO camera under controlled light conditions. Leaf scans were evaluated with the L*a*b*-color system. This is a three-dimensional system with parameter a* describing the green/red percentage and parameter b* the blue/yellow percentage of a color. L* represents the lightness of a color. The a* and b* parameters provided good prediction of N, P, Mg, and Fe status of the plants in the wavelength ranges of 380-390 am, 430-780 nm, 516-780 nm, 516-IR, and 540-600 nm because reflectance changed specifically due to the nutrient deficiency. Analyses of water-soluble and propanol-soluble pigments showed no significant changes in absorbance during latent deficiency. The results indicate that reflectance measurements may provide a powerful tool for the specific detection of latent nutrient deficiencies in corn plants.