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United States Department of Agriculture

Agricultural Research Service



2012 Annual Report

1a. Objectives (from AD-416):
1) Improve existing aerial application technologies to maximize efficiency and biological efficacy of crop production and protection compounds with minimal spray drift and impact to non-target systems. Subobjective 1A: Develop and implement standard procedures for evaluating drift reduction technologies (DRTs) and assessing biological impacts of sprays in crop canopies. Subobjective 1B: Develop and optimize the use of autonomous unmanned aerial vehicles (UAVs) for pest control. Subobjective 1C: Assess biological impacts of spray drift. 2) Develop remote sensing and variable rate aerial application systems that enhance detection, prevention, and control of plant diseases, nutritional deficiencies, or insect damage in annual and perennial crops. Subobjective 2A: Characterize spatial variability of crop conditions using multispectral imaging to develop treatment maps for use with site-specific aerial application systems. Subobjective 2B: Integrate remote sensing and variable rate aerial application technologies to optimize crop management strategies. Subobjective 2C: Develop sensors that rapidly and/or remotely detect pest presence, crop condition, spray droplets, and volatile organic compounds. Subobjective 3D: Adapt autonomous unmanned aerial vehicles (UAVs) for remote sensing of crop conditions. 3) Develop, enhance, and implement decision support systems that improve user ability to select and operate application equipment and schedule spray treatments that optimize biological efficacy. Subobjective 3A: Correlate aerial spray dispersion model estimates with off-target biological effects and in-swath deposition. Subobjective 3B: Develop and implement crop growth and management decision systems to optimize aerial applications.

1b. Approach (from AD-416):
Utilizing engineering and biological principles, laboratory and field studies will be conducted to evaluate the effects of various aerial application parameters, such as spray formulation and droplet size spectrum, on aerial application efficiency and biological efficacy. Efforts will focus on the integration of remote sensing and variable rate application systems to maximize the efficacy of crop production materials while minimizing any off-target impact from these sprays. Decision support systems will be developed that help applicators, farmers, and crop consultants in making the correct treatment decisions to protect a crop from pests. This project will develop and implement new and improved aerial application technologies for safe, efficient, and sustainable crop production and protection.

3. Progress Report:
Work under this project during FY 2012 resulted in significant progress in improving the efficacy of crop production and protection materials, enhancing the use of remote sensing and precision application in crop production systems, and modeling spray droplet movement. Tests were conducted in high-speed and low-speed wind tunnels to determine the levels of spray drift mitigation from a number of spray nozzles and formulations. These projects support the EPA Drift Reduction Technology Program. Biological assessments of various mosquito control products, application rates, and bioassay cages were conducted in a new ARS wind tunnel maintained by the project. Smartphone applications were developed for the iPhone and Android platforms that transfer the ARS aerial spray research data into more useful formats for project customers and are provided free of charge. A volatile organic compound analyzer was further evaluated in a low speed wind tunnel using a mosquito control product; the data showed that the analyzer detected the temporal signature and magnitude of a spray cloud containing insecticide as it moved past the analyzer. Remote sensing studies were conducted that identified diseased cotton, and volunteer cotton in ditches and waterways. Multidata fusion techniques and technologies were shown to enhance the accuracy of field crop structure analyses as compared to single sensor assessments. Significant progress was made in FY 2012 in development of spray deposition and drift models, which will be utilized to help spray applicators make more informed decisions on issues related to spray application needs and ways to minimize the chances of off-target spray drift. Project scientists during FY 2012 served on numerous occasions as experts in the aerial application industry and were sought out for advice and consultation by industry and academic research personnel, and by officials with the EPA, Dept. of Homeland Security, Dept. of Defense, USDA-APHIS, and representatives from numerous state agencies and organizations.

4. Accomplishments
1. New protocols for spray drift reduction. Spray drift is a critical concern for aerial applicators, and numerous new spray technologies including nozzles, spray formulations, adjuvants, and operational practices may significantly reduce drift potential. However, there is a need to standardize measurement and evaluation methods so as to provide better guidance to applicators for enhancing drift reduction. In cooperation with EPA and other research and manufacturing entities, ARS scientists at College Station, Texas, refined and tested protocols to evaluate droplet size and drift of aerially applied spray using drift reduction technologies. Objective criteria were used to quantify the performance of drift reduction technologies, and large-scale model simulations provided guidance on best operational practices such as droplet size, swath offset, and application height. These new protocols will be used by applicators to counter meteorological and other in-field conditions that can elevate drift potential. The results will be better on-target deposition of aerial sprays, less drift, and more environmentally sensitive utilization of agricultural chemicals.

2. Spectral data characterize cotton cultivars and other crops. Remotely acquired ground-based methodology to discriminate different crop species, disease status, and overall crop condition would be valuable in assessing crop status and making input decisions. ARS scientists at College Station, Texas, showed that different cotton types and corn, sorghum, soybean, and cotton during various growth stages could be characterized using spectral properties. The work showed that the reflectance spectra of plants could be used to readily differentiate among crop types at the early vegetative and late growth stages. The work clearly established that technologies can be developed to aid in efficient monitoring of crop status and in making informed crop management decisions.

Review Publications
Lopez, J., Latheef, M.A., Hoffmann, W.C. 2011. Effect of abamectin on feeding response, mortality, and reproduction of adult bollworm (Lepidoptera: Noctuidae). Southwestern Entomologist. 36:155-166.

Zhang, H., Lan, Y., Suh, C.P., Westbrook, J.K., Lacey, R., Hoffmann, W.C. 2012. Spectral properties of crops at different growth stages. Transactions of the ASABE. 55:1-8.

Lopez, J., Latheef, M.A., Hoffmann, W.C. 2011. Effect of Hexaflumuron on feeding response and reproduction of bollworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae). Southwestern Entomologist. 36(3):247-259.

Zhang, H., Hinze, L.L., Lan, Y., Westbrook, J.K., Hoffmann, W.C. 2012. Discriminating among cotton cultivars with varying leaf characteristics using hyperspectral radiometry. Transactions of the ASABE. 55(1):275-280.

Fritz, B.K., Hoffmann, W.C., Bretthauer, S., Wolf, R.E., Bagley, W.E. 2012. Wind tunnel and field evaluation of drift from aerial spray applications with multiple spray formulations. Journal of ASTM International. doi 10-1520/STP104403.

Fritz, B.K., Hoffmann, W.C., Bagley, W.E. 2012. Effect of formulated glyphosate and adjuvant tank mixes on atomization from aerial application flat fan nozzles. Journal of ASTM International. doi 10.1520/STP104451.

Hoffmann, W.C., Walker, T.W., Fritz, B.K., Farooq, M., Smith, V.L., Robinson, C.A., Lan, Y. 2012. Further evaluation of spray characterization of sprayers typically used in vector control. Journal of the American Mosquito Control Association. 28(2):93-101.

Huang, Y., Zhan, W., Fritz, B.K., Thomson, S.J. 2012. Optimizing selection of controllable variables to minimize downwind drift from aerially applied sprays. Applied Engineering in Agriculture. 28(3):307-314.

Last Modified: 06/21/2017
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