Increasing pressure from industry and environmental sectors has begun to force the

Australian cotton industry to rethink its approach to chemical application. This has

led to an increase in ground-based applicators this current year to a record number.

While this is a positive step, it in effect deregulates the industry, moving from a

highly accurate controlled rate applicative technique by a small number of highly

trained operators to a large number of relatively unskilled applicators. As a result the

application of a given chemical in a field and growing area may vary widely with little or no control.

Ground based application of insecticides does allow for banding of costly or limited products, timely application when conditions are more conducive to maximum efficacy, and for optimum target efficiencies. New spraying units offer wide booms, high load capacity, high clearance, air assist nozzles, four wheel drive and speed that combined are able to compete with aerial based application.This project was designed to consider the issues involved in the spraying task and aimed to coordinate efforts with other researchers to achieve the following:

I) Benchmarking of current operational parameters of ground based spray application equipment and techniques. This included the recognition of grower questions and concerns regarding their current practice.

2) Summarising the results from the survey and define the areas of concern that can

be readily addressed. These may include but are riot limited to the effect of speed

on application, use of shields, end of row problems, and nozzle configuration (angle

of incidence, number, position). This will be done in the wind tunnel (if practical) and the field.

3) Develop documentation of project outcomes and report back to the industry. This will include testing protocols, a listing of datum settings for ground based application rigs and recommendations of changes with increasing bush size.