Pest Management – Australia

Integrated pest management

Management of insect pests has been a key challenge for cotton farmers in Australia. From the 1960s to 1990s, cotton farmers relied almost exclusively on regular application of insecticides that generally had a limited range of modes of action. This inevitably led to pesticide resistance in the pests, secondary pest outbreaks, destruction of natural enemies and increased risks from off-farm movement and environmental concerns.

To address the need for better pest management options, the cotton industry funded significant research and practice change projects, including training to encourage IPM adoption by farmers.

IPM practices widely used in Australian cotton include:

• Use of transgenic crop traits in varieties
• Soft chemistry options that preserve beneficial species
• Use of crop spray thresholds
• Insecticide Resistance Management Strategy
• Trap and refuge crops
• Regular insect crop scouting (twice weekly)
• Crop rotations
• Weed control
• Native vegetation

A 2011/12 survey of cotton consultants (agronomists) added more specific evidence of the widespread adoption of IPM across Australia. Survey results showed moderate/high use of industry-recommended pest thresholds for spray decisions to control mirids, and high/very high use of industry-recommended thresholds for making spray decisions to control silverleaf whitefly.

Adoption of biotechnology

In combination with IPM, the adoption of transgenic cotton varieties – with both insect- and herbicide-tolerant traits – has helped Australian growers drastically reduce pesticide applications.

The International Cotton Advisory Committee (ICAC), a body that assists governments in fostering a healthy world cotton economy, reported, “Indirect significant benefits of the [transgenic] technology include improved populations of beneficial insects and wildlife in cotton fields, reduced pesticides runoff, and improved farm worker and neighbor safety as well as soil-related environmental improvements through changed tillage practices with herbicide-tolerant varieties” (ICAC, 2004).

Herbicide tolerance technology has played an important role in the move away from conventional tillage to conservation tillage production systems. When cotton is safe from the effects of herbicide, the plant cover growing between rows can be sprayed rather than tilled. This change in production system has reduced levels of greenhouse gas emissions from reduced tractor fuel use and facilitated soil carbon sequestration. Conservation tillage also conserves topsoil, preserves soil moisture and reduces runoff. Another benefit of herbicide-tolerant technology is an improvement in water quality through the use of more benign herbicides that rapidly dissipate (Carpenter et al., 2002).