Estimating Light Interception by Cotton Using a Digital Imaging Technique
Evangelos D. Gonias
Department of Crop, Soil and Environmental Sciences, University of Arkansas, 1366 Altheimer Drive, Fayetteville, AR 72704, USA.
Derrick M. Oosterhuis *
Department of Crop, Soil and Environmental Sciences, University of Arkansas, 1366 Altheimer Drive, Fayetteville, AR 72704, USA.
Androniki C. Bibi
Department of Crop, Soil and Environmental Sciences, University of Arkansas, 1366 Altheimer Drive, Fayetteville, AR 72704, USA.
Larry C. Purcell
Department of Crop, Soil and Environmental Sciences, University of Arkansas, 1366 Altheimer Drive, Fayetteville, AR 72704, USA.
*Author to whom correspondence should be addressed.
Abstract
Radiation intercepted by the crop canopy is directly correlated to dry matter accumulation. Calculation of fractional light interception by the crop is commonly performed by measuring photosynthetically active radiation above and below the canopy using a line-source quantum sensor. However, this method is limited by the time of measurement and the presence of clouds. For soybeans grown in 19-cm rows, ground coverage values estimated from digital images taken above the canopy have been correlated to light interception measurements, but there have been no reports of using this method in cotton or in other crops on wide rows. In this study, a digital imaging technique was used to establish a relationship between fractional canopy coverage and fractional light interception for cotton. This study suggests that digital imagining may be used as an alternative technique for estimating light interception by cotton.
Keywords: Canopy coverage, cotton, digital imaging, light interception.