Determining the Relative Canopy Coverage with a Digital Image and Adobe Photoshop®: A Pilot Project to Introduce a Low Cost Technique

Abstract

Determining canopy coverage in rice (Oryza sativa L) between the 4th tillering stage to internode elongation to harvest allows the assessment of the degree of tillering and indicates the adequacy of the nitrogen fertilization program. This investigation is a technique project to determine if images obtained from moderately priced digital cameras ($200–$300 range) and commercially available imaging processing software (Abode Photos hop®) may effectively estimate the percent canopy coverage. The image analysis is performed using the “magic wand” feature in the software package to isolate and then recolor the soil using the “paint bucket” feature to enhance the color contrast. The second procedure involves overlaying the image with a grid so the percent canopy cover area can be estimated for the area of the photograph. Preliminary work in the field shows that this technique can discriminate canopy coverage in high and low nitrogen plots in rice.