Validation of SpraySafe Manager, an aerial herbicide application decision support system

Abstract

Spray Safe Manager (SSM) is a computer-based aerial application model, which unlike previous models, has a simple user interface. SSM not only predicts spray deposition but also integrates this data with herbicide-plant dose-response curves. This latter facility allows the operator to predict the size of buffer zone required to avoid damage to sensitive plants outside the spray area and the degree of weed control within the spray block. Validation trials showed that, for a helicopter applied spray, the model tended to overpredict spray deposition on stainless steel plates close to the spray block and underpredict deposition in the region 32-80 m from the centre of the spray release line and on isolated plants. The accuracy of model prediction was greater when the spray was applied using D8-45 nozzles orientated at 90°, than for spray applied using D6 nozzles orientated at 0°. The reasons for this are discussed. The model can also be used to predict possible work rates, hectares sprayed per hour, and potentially as a training tool.

A survey of herbicide use and a review of environmental fate in New Zealand planted forests

“…Additionally, spray drift can occur during aerial application that may result in the herbicide being carried out of the treated area to a nearby water body (Holvoet et al 2007;Thistle et al 2009). This last factor is largely controlled through the use of appropriate buffer zones to avoid direct application into streams and off-target vegetation (Ray et al 1998;Richardson et al 2004;Neary et al 2009). The following discussion more closely examines the literature pertaining to the environmental fate of these two herbicides in forest environments and relates these findings to the forest industry in New Zealand.…”

Foliar Interactions and Uptake of Agrichemical Formulations–Present Limits and Future Potential

“…[12] Although the droplet size distribution of agrichemical sprays cannot currently be forecast or modelled, the droplet spectra can be easily determined, and that information, together with other operational parameters, put into models of spray deposition. Models have been developed for ground and aerial spray application [13,14,15]. The advantage of such models is that they can be used pre-application to optimise deposition, and if biological efficacy or ecotoxicity information is available, to also estimate the efficacy of the deposited spray, and any required buffer distances, aquatic deposition and dose, or offtarget bio-accumulation or persistence of the driftable fraction [16].…”