Evaluating Water Status in Potato Fields Using Combined Information from RGB and Thermal Aerial Images
Potato yield and quality are highly dependent on an adequate supply of water. In this study the combined information from RGB and thermal aerial images to evaluate water status in potato fields was examined. Irrigation experiments were conducted on commercial potato fields (Desiree; drippers). In 2011, three water levels (100%, 70%, and 50%) were induced with three replicates and two thermal and RGB aerial images were acquired. Vegetation indices were extracted from the RGB and used for distinguishing vegetation from soil. Canopy temperature was then delineated from the thermal images. Crop water stress index (CWSI) was calculated for each replicate, using various minimum reference temperatures (Twet) and the empirical evaluation of maximum reference (Tdry; Tair+50 C). Statistical tests and comparison with stomatal conductance measurements were made to evaluate the differences between water levels while employing the various CWSI values. CWSI effectiveness in identification of water status is discussed.