Co-Authors:
Rosenberg, O., Department of Sensing, Information and Mechanization Systems, Institute of Agricultural Engineering, Agricultural Research Organization (A.R.O), Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel, Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel
Cohen, Y., Department of Sensing, Information and Mechanization Systems, Institute of Agricultural Engineering, Agricultural Research Organization (A.R.O), Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
Saranga, Y., Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel
Levi, A., Department of Sensing, Information and Mechanization Systems, Institute of Agricultural Engineering, Agricultural Research Organization (A.R.O), Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
Alchanatis, V., Department of Sensing, Information and Mechanization Systems, Institute of Agricultural Engineering, Agricultural Research Organization (A.R.O), Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
Abstract:
In previous studies, a model for assessing leaf water potential (LWP) in cotton plants based on Crop Water Stress Index (CWSI) calculated using ground thermal imagery and artificial wet reference (AWR), as the minimum temperature, was developed and validated. The AWR cannot be measured from aerial thermal images and in order to implement this approach, it is essential to characterize the minimum boundary reference temperature and to evaluate the validity of the CWSI-LWP relationship. Four types of minimum references were examined: artificial, theoretical, plant and virtual. Three aerial thermal images were acquired above a cotton field. The best relationship was found between calculated and measured LWP using the virtual reference: high correlation and 1:1 fit. This means that a reliable LWP map of a cotton field can be created using only an aerial thermal image and air temperature. Using the LWP-CWSI relationship, the LWP can be mapped for each pixel or for each area of interest such as an irrigation section or pre-defined management zone.