USE OF NONDESTRUCTIVE SPECTROSCOPY TO ASSESS CHLOROPHYLL AND NITROGEN IN FRESH LEAVES PINGHAI DING [...]... selecting and using optimum wavelengths to develop indices for Chl assessment (OWChl), (2) understanding how the methods for developing indices influence the accuracy of Chl assessment; (3) identifying indices parameters that can be used to increase accuracy of Chl assessment across genotypes; and (4) understanding what factors influence the accuracy of commercially available meters used for Chl and N assessment... made in understanding (1) interactions between leaf and light characteristics in the visible and infrared regions of the spectrum, (2) how to develop indices for Chl and vegetation (or greenness) assessment, and 3) the effects of leaf properties on the accuracy of leaf Chl and N estimates However, many aspects that influence the accuracy of Chl and N assessment remain to be elucidated, including (1)... conversion of meter output (Reading) into chlorophyll and N concentrations based the calibration for specific cultivars 202 USE OF NONDESTRUCTIVE SPECTROSCOPY TO ASSESS CHLOROPHYLL AND NITROGEN IN FRESH LEAVES CHAPTER 1 INTRODUCTION Nitrogen (N), an essential macroelement required for plant growth, is the most commonly used nutrient in fertilizer to increase plant productivity (Below 1995, Meisinger... equations and converting index values from meters to chlorophyll and nitrogen concentrations 200 A.8 Screen shot of the PING software Standard Setup screen showing calibration information of specific cultivars based on output from meter (Reading) and chlorophyll and nitrogen concentrations measured by standard chemical methods 201 A.9 Screen shot of the PING software Conversion screen showing... canopy-level chlorophyll (Chl) assessment in remote sensing 81 4.2 Peak range and optimum wavelengths (OWChl) for assessment of different chlorophyll (Chl) types (Chl a, Chl b and Chl a+b) in poplar leaves 82 4.3 The accuracy of using published indices and calibration equations for assessing chlorophyll a (Chl a) in poplar leaves 83 4.4 The accuracy of using published indices and. .. were to 1) determine the best methods for selecting OWChl and OWN and developing indices for Chl and N assessment; 2) characterize how plant genotype and variation in leaf texture, water status, and pigments influence Chl assessment; 3) identify how parameters in hand-held meters used to assess Chl influence meter accuracy; and 4) develop a hand-held meter with higher accuracy and sensitivity for nondestructive. .. Map of chlorophyll concentrations (µg.m-2) in leaves of pot -in- pot ‘Gala' apple trees growing in Lewis-Brown Horticulture Farm in Corvallis, Oregon 198 A.6 Map of nitrogen (N) concentrations (%) in leaves of pot -in- pot ‘Gala' apple trees growing in Lewis-Brown Horticulture Farm in Corvallis, Oregon 199 A.7 Screen shot of the PINGS software start-up screen used for developing... for assessing chlorophyll b (Chl b) in poplar leaves 84 4.5 The accuracy of using published indices and calibration equations for assessing chlorophyll b a+b (Chl a+b) in poplar leaves 85 4.6 The accuracy and calibration equations of the published indices after the Chl-related wavelength replaced by the optimal wavelength for assessing chlorophyll (Chl a, Chl b and Chl a+b in poplar leaves. .. application of N to crops can lead to contamination of ground and surface water supplies while too little available N can result in reduced yield and profit (Bullock and Anderson 1998) Efficient N management to achieve optimum productivity while preserving and enhancing the crop quality requires frequent plant testing to ensure that neither too much nor too little N is applied The chlorophylls, Chl a and Chl... transmission values and total chlorophyll (Chl) concentrations at 1 nm intervals from 300nm to 1100 nm in leaves of poplar (A, D), apple (B, E) and almond (C, F) 162 6.6 Curves of coefficients of determination (R2) and root mean square error (RMSE) for the relationships between reflectance values and total chlorophyll (Chl) concentration at 1 nm intervals from 300nm to 1100 nm in leaves of poplar (A, D), . DEVELOPMENT OF A TRANSMMISION HAND-HELD METER FOR ASSESSING CHLOROPHYLL AND NITROGEN IN FRESH LEAVES 182 APPENDIX B. CONCENTRATION OF TOTAL CHLOROPHYLL (CHL) AND NITROGEN (N) IN LEAVES OF . output (Reading) into chlorophyll and N concentrations based the calibration for specific cultivars 202 USE OF NONDESTRUCTIVE SPECTROSCOPY TO ASSESS CHLOROPHYLL AND NITROGEN IN FRESH LEAVES. Use of Nondestructive Spectroscopy to Assess Chlorophyll and Nitrogen in Fresh Leaves by Pinghai Ding A DISSERTATION submitted to Oregon State University in partial