Evaluating Airborne Normalized Difference Vegetation Index Imagery for Citrus Orchard Surveys

Abstract

<jats:p>The normalized difference vegetation index (NDVI) provides relative estimates of vegetation vigor, density, and health. Little information is available on the application of NDVI imagery for citriculture. The objective of this study was to evaluate airborne NDVI imagery for assessing tree conditions in citrus (<jats:italic>Citrus</jats:italic> spp.) orchards. Images of two south Texas citrus groves with stressed and nonstressed trees were qualitatively evaluated. Stressed trees were easily detected from nonstressed trees in the images. The images were also helpful for developing survey plans of the citrus groves. Our results indicated that airborne NDVI images could be used as a tool to assess tree conditions in citrus orchards. Findings should be of interest to citrus growers, extension agents, agricultural consultants, and private surveying companies.</jats:p>

Land cover classification and economic assessment of citrus groves using remote sensing

“…The NDVI has been used extensively to determine vegetation vigor in forestry and environmental evaluations, but little information exists on its use in citrus agriculture. Fletcher et al (2004) found airborne NDVI imagery to be useful in detecting stressed from non-stressed trees when evaluating the condition of citrus groves and in planning surveys of such groves. Both remote sensing technology and image processing methods are becoming refined, thus offering an increasingly wide range of research applications in the crop sciences.…”

Nutrient Management Zones for Citrus Based on Variation in Soil Properties and Tree Performance

“…The very small size trees in the grove were from resetting after tree loss from freezes and disease. The strong significant correlation between MVs and NDVI supports the idea that NDVI could be used to estimate tree size and vegetation vigor (Fletcher et al 2004). …”

“…The normalized difference vegetation index (NDVI) calculated from easily available aerial photography of citrus groves (http://data.labins.org/2003/MappingData/DOQQ/doqq_99_utm.cfm) could be used for making sampling strategy and management zones. NDVI can be used for relative estimation of citrus tree health, vegetation vigor and density (Fletcher et al 2004). Whitney et al (1999) described yield maps showing spatially variable yield significantly correlated to tree canopy size determined from aerial photography.…”

Multilevel systematic sampling to estimate total fruit number for yield forecasts

“…A number of studies have found positive correlations between NDVI and canopy vigour, yield and quality of fruit (e.g. Johnson et al 2003;Fletcher et al 2004;Best and Zamora 2008;Hall et al 2011;Mann et al 2011). The NDVI was computed on a per orchard basis and the low, medium and high classifications were based on 33rd percentile values.…”