Spectral detection of micronutrient deficiency in 'Bragg' soybean.

Iron and Mn deficiency are the most common micronutrient deficiencies in soybean [Glycine max (L.) Merr.] in the United States, although deficiencies in Zn and Cu have also been observed in the field. This study was conducted to assess the utility of leaf fluorescence and reflectance as a rapid means of detecting Mn, Zn, Fe, and Cu deficiency, and to determine whether spectral methods could be used to derive critical concentration levels for Mn, Fe, Zn, and Cu. Bragg' soybean plants were raised as seedlings in aerated, chelator-buffered nutrient solutions in a growth chamber. Manganese, Zn, Cu, and Fe were supplied over a wide range of concentrations to induce a range of deficiency symptoms. Chlorophyll concentrations and reflectance and fluorescence characteristics of the youngest fully mature leaf were measured periodically. Reflectance characteristics responded to decreases in leaf total chlorophyll concentration, while fluorescence characteristics responded to changes in electron transport associated with Mn, Zn, Cu, or Fe deficiency. Critical concentration ranges estimated from spectral measures were 9 to 10 mg kg -1 for Mn, 12 to 18 mg kg -1 for Zn, 45 to 50 mg kg -1 for Fe, and 1.0 to 1.5 mg kg -1 for Cu. The spectral measures used in this study were useful in detecting Mn, Zn, Fe, and Cu deficiencies and may provide a rapid, nondestructive method for the detection of these deficiencies in the growth chamber, greenhouse, or field. The spectral measures were also useful for establishing critical levels for Mn, Zn, Fe, and Cu under controlled conditions.

[1]  William Philpot,et al.  The derivative ratio algorithm: avoiding atmospheric effects in remote sensing , 1991, IEEE Trans. Geosci. Remote. Sens..

[2]  K. Ohki.  Critical Zinc Levels Related to Early Growth and Development of Determinate Soybeans1 , 1977 .

[3]  M. Droppa,et al.  The Role of Copper in Photosynthesis , 1990 .

[4]  J. Anderson,et al.  The fluorescence properties of manganese-deficient spinach chloroplasts. , 1968, Biochimica et biophysica acta.

[5]  László Kocsányi,et al.  Spectrometer for fast measurements of in vivo reflectance, absorptance, and fluorescence in the visible and near-infrared , 1994 .

[6]  J. Riggs,et al.  The critical concentration of manganese in barley , 1987 .

[7]  H. Dau.  New trends in photobiology: Short-term adaptation of plants to changing light intensities and its relation to Photosystem II photochemistry and fluorescence emission , 1994 .

[8]  D. Porath,et al.  Chlorophyll determination in intact tissues using n,n-dimethylformamide. , 1980, Plant physiology.

[9]  H. Marschner,et al.  High Light Intensity Enhances Chlorosis and Necrosis in Leaves of Zinc, Potassium, and Magnesium Deficient Bean (Phaseolus vulgaris) Plants , 1989 .

[10]  P. Kriedemann,et al.  Photosynthetic dysfunction and in vivo changes in chlorophyll a fluorescence from manganese-deficient wheat leaves , 1985 .

[11]  K. Ohki.  Manganese Deficiency and Toxicity Levels for ‘Bragg’ Soybeans 1 , 1976 .

[12]  C. Perry,et al.  Functional equivalence of spectral vegetation indices , 1984 .

[13]  William D. Philpot,et al.  Yellowness index: An application of spectral second derivatives to estimate chlorosis of leaves in stressed vegetation , 1999 .

[14]  J. Pushnik,et al.  Iron regulation of chloroplast photosynthetic function: Mediation of PS I development , 1989 .

[15]  R. Graham,et al.  Diagnosis and prognosis of manganese deficiency in Lupinus angustifolius L , 1985 .

[16]  W. E. Jones,et al.  Fitting Plants Nutritionally to Soils. I. Soybeans 1 , 1977 .

[17]  J. Abadía,et al.  Chlorophyll Fluorescence and Photon Yield of Oxygen Evolution in Iron-Deficient Sugar Beet (Beta vulgaris L.) Leaves. , 1991, Plant physiology.

[18]  A. Castelfranco,et al.  Effects of Iron and Oxygen on Chlorophyll Biosynthesis : I. IN VIVO OBSERVATIONS ON IRON AND OXYGEN-DEFICIENT PLANTS. , 1982, Plant physiology.

[19]  P. Kriedemann,et al.  Growth and photosynthetic responses to manganese and copper deficiencies in wheat (Triticum aestivum) and barley grass (Hordeum glaucum and H. leporinum) , 1988 .

[20]  Ross M. Welch.  Micronutrient Nutrition of Plants , 1995 .

[21]  J. H. Manwaring,et al.  The role of iron in higher plant chlorophyll biosynthesis, maintenance and chloroplast biogenesis , 1984 .

[22]  W. E. Jones,et al.  Fitting Plants Nutritionally to Soils. II. Cotton1 , 1977 .

[23]  W. Inskeep,et al.  Extinction coefficients of chlorophyll a and B in n,n-dimethylformamide and 80% acetone. , 1985, Plant physiology.

[24]  C. Tucker.  Red and photographic infrared linear combinations for monitoring vegetation , 1979 .

[25]  F. Cox,et al.  Evaluation of the Need for Copper with Several Soil Extractants 1 , 1983 .

[26]  R. Graham,et al.  The Critical Concentration of Manganese in Field-grown Wheat , 1985 .

[27]  J. Barroso,et al.  Effect of copper deficiency on photosynthetic electron transport in wheat plants , 1990 .