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Estimating Nitrogen Content of Sweet Pepper Leaves by Reflectance Measurements 1
Author(s) -
Thomas J. R.,
Oerther G. F.
Publication year - 1972
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1972.00021962006400010004x
Subject(s) - reflectivity , pepper , capsicum annuum , greenhouse , horticulture , nitrogen , botany , mathematics , chemistry , agronomy , biology , optics , physics , organic chemistry
A study was conducted to determine the feasibility of using spectrophotometrically measured diffuse light reflectance from top (adaxial) leaf surfaces of sweet pepper ( Capsicum annum , L. var. ‘Yolo Wonder’) leaves to quickly estimate their N status. Reflectance was found to be inversely correlated (p = 0.01) with the leaf N content. Regression equations expressing reflectance as a function of leaf N content of greenhouse‐grown sweet peppers were used to estimate the N content of fieldgrown sweet peppers. The difference between Kjeldahldetermined and reflectance‐estimated N contents was less than 0.7%. The regression equation at the 550‐nm wavelength suggests that near the 4% N level a 1% change in reflectance would change the predicted N content by 0.2%. Results show that leaf reflectance can be used to quickly estimate the N status of sweet peppers.