Shielded sprayers have traditionally been used for inter-row spraying in farming systems where wider row spacings are common, such as in the northern grains region where crop row spacing for summer cereals and some pulse crops can be one metre or more.

However, shielded sprayers are now being used in areas with much narrower crop row spacings, particularly in some of the higher-rainfall areas in the southern grains region. This use in narrower crop spacings has been in response to increased levels of resistance to selective herbicides, as well as the greater accuracy of GPS systems and the use of toolbars that can adjust the shield position in relation to the crop row.

There are a several things the spray operator must consider before purchasing or setting up a shielded sprayer for inter-row spraying including:

• product choice - Is the desired herbicide registered for interrow spraying within the crop (or is there an appropriate permit in place)?;

• determining the applied rate and nozzle selection;

• obtaining a uniform deposit under the shield;

• maintaining the shield height close to the ground;

• keeping the shield in the inter-row; and

• using manual pressure or rate controllers.

This module outlines some of the practical considerations associated with using a shielded sprayer for inter-row spraying within a crop.