A review of ground sprayer data and a preliminary analytical model

This paper summarizes the ground sprayer data collected by the Spray Drift Task Force (SDTF) and discusses its implementation as the Tier I model in AgDRIFT®. Preliminary analytical Lagrangian ground sprayer modeling efforts by the SDTF and the USDA Forest Service, to accurately and rapidly predict the deposition downwind from a spray block for any set of initial conditions, are also discussed

Suggested revisions to ASAE standard S572 Aug99

The development of ASAE Standard S572 Aug99 helped the industry and applicators respond to drift issues raised by the U. S. Environmental Protection Agency and concerned environmental groups. However, application of the standard to existing nozzles and tank mixes raised three concerns: (1) how to classify a drop size distribution when the drop size spectrum crosses classification categories; (2) how to define the driftable portion of a drop size distribution; and (3) how to expand the ASAE Standard so as to better delineate classification categories. The first question was addressed in a paper presented at the NAAA/ASAE meeting in December 2003 in Reno, NV, in which it was demonstrated that the standard should be used to recover drift potential, correlated to readily determined parameters such as D , D , and D , and thereby unambiguously nail classification categories for all nozzles and tank mixes. The second and third questions will be addressed in this paper, by determining the drop size that drifts from an aerial application and by proposing additional reference nozzles to expand the classification categories

The need for nozzle emission spectra in drift mitigation

Aerial application models, such as AgDRIFT®, rely on an accurate nozzle emission spectrum to quantify the effects of atomization on deposition and drift. In this paper we explore the consequences of approximating the droplet size distribution and the implications of the accuracy of that approximation for downwind drift and the setting of buffer zones

Development of the spray drift task force database for aerial applications

This article is part of a series describing the development of the Spray Drift Task Force (SDTF) database and its application to agricultural chemical exposure risk assessment modeling. The series describes the development of a large generic database (assuming that active ingredient rate is not a factor affecting physical drift) and its use in estimating spray movement immediately following application by aerial methods. The components of the database are described. In agreement with field trials in the open literature, the database shows that the major variables affecting off-target spray deposition are droplet size, spray release position (boom height and length), and wind speed and direction. In addition, secondary parameters that can affect these variables and drift are also discussed