Sectioning remote imagery for characterization of Avena sterilis infestations. Part A: Weed abundance

Abstract

Software was developed to spatially assess key crop characteristics from remotely sensed imagery. Sectioning and Assessment of Remote Images (SARI ®), written in IDL ® works as an add-on to ENVI ®, has been developed to implement precision agriculture strategies. SARI ® splits field plot images into grids of rectangular >micro-images> or >micro-plots>. The micro-plot length and width were defined as multiples of the image spatial resolution. SARI ® calculates different indicators for each micro-plot, including the integrated pixel digital values. Studies on weed patches were done with SARI ® using ground-truth data and remote images of two wheat plots infested with Avena sterilis at LaFloridaII and Navajas (Southern Spain). Patches of A. sterilis represented 47.5 and 19.2% of the field areas at the two locations, respectively; the infested areas were a combination of a few large and several small patches. At LaFloridaII, 2.1% of all patches were >500 m 2 and 55.0% of all patches were smaller than 10 m 2. Based on ground-truth weed abundance data, SARI ® output includes geo-referenced and visual herbicide prescription maps, which could be used with variable-rate application equipment. © 2011 Springer Science+Business Media, LLC.