Site-specific Approaches to Cotton Insect Control. Sampling and Remote Sensing Analysis Techniques

Abstract

When insect population density varies within the same cotton field, estimation of abundance is difficult. Multiple population densities of the same species occur because cotton fields (due to edaphic and environmental effects) are apportioned into various habitats that are colonized at different rates. These various habitats differ temporally in their spatial distributions, exhibiting varying patterns of interspersion, shape and size. Therefore, when sampling multiple population densities without considering the influence of habitat structure, the estimated population mean represents a summary of diverse population distributions having different means and variances. This single estimate of mean abundance can lead to pest management decisions that are incorrect because it may over-or under-estimate pest density in different areas of the field. Delineation of habitat classes is essential in order to make local control decisions. Within large commercial cotton fields, it is too laborious for observers on the ground to map habitat boundaries, but remote sensing can efficiently create geo-referenced, stratified maps of cotton field habitats. By employing these maps, a simple random sampling design and larger sample unit sizes, it is possible to estimate pest abundance in each habitat without large numbers of samples. Estimates of pest abundance by habitat, when supplemented with ecological precepts and consultant/producer experience, provide the basis for spatial approaches to pest control. Using small sample sizes, the integrated sampling methodology maps the spatial abundance of a cotton insect pest across several large cotton fields.

Effects of Field Plot Size on Variation in White Flower Anther Injury by Tarnished Plant Bug for Host Plant Resistance Evaluations in Arkansas Cotton

“…In contrast, this study on WFAI did not indicate effects of plot size, possibly because adult TPB have the behavioral capacity to spatially disperse themselves in a manner that matches the host plant suitability of the cotton crop [10][11][12][13].…”

“…This experimental structure was motivated by experiences learned in commercial cotton fields on TPB abundance and interspersion among crop habitat categories mapped through remote sensing analyses by Willers and colleagues [10][11][12][13]. Consequently, it is important to recognize that knowledge learned from prior experiments is a valuable resource for new technologies.…”

Remote Sensing and Reflectance Profiling in Entomology

“…As a hypothetical example, suppose remote sensing is used to assess insect-induced stress responses in experimental field plots with a crop grown under three irrigation regimes, "a," "b," and "c." We assume that no pesticides are used and that all stressors can be controlled. To study this, 30 experimental field plots could be established, in which 15 (five replications from each irrigation regime) are experimentally infested and the remaining 15 144 Nansen…”

The Illuminating Role of Laser Scanning Digital Elevation Models in Precision Agriculture Experimental Designs - An Agro-Ecology Perspective

“…Nevertheless, it is necessary to briefly discuss sources of error and standards for laser scanning data to provide a common starting point. This discussion is anchored to a specific agricultural landscape (Figure 4), where more than 22 years of research on site-specific crop and site-specific insect pest management involving laser scanning, proximal and remote sensing systems, and crop yield monitors has been accomplished (Anonymous, 2000;Campenella, 2000;Dupont et al, 2000;Frigden et al, 2002;McKinion et al, 2009Milliken et al, 2010;Willers et al, 1990Willers et al, , 1992Willers et al, , 1999Willers et al, , 2004Willers et al, , 2000Willers et al, , 2005Willers & Riggins, 2010).…”

“…These digital raster layers permit sample data of an ecological population of interest to be collected from distinct habitats of crop growth (Willers et al, 2005;Willers & Riggins, 2010). When appropriately processed, the raster information can be linked to the ground sample data, allowing for the creation of additional data products describing the population characteristics as a geo-referenced map.…”