Southern region growers will be armed with greater knowledge about integrated pest management (IPM) thanks to a GRDC investment being led by the Birchip Cropping Group (BCG).

The investment, ‘Supporting the sustainable use of insecticides and local on-farm implementation of IPM strategies in the GRDC southern region’, is looking to provide knowledge and skills to growers so they are equipped with a range of appropriate IPM strategies for their situations.

IPM strategies help:

• delay the onset of insecticide resistance;
• minimise any potential impact on beneficial insects and natural enemies; and
• minimise the long-term economic impact associated with insect pest control in grain crops.

Insecticides place selection pressure on insect pests of agricultural crops to evolve resistance. Many pest species have developed resistance against the major insecticidal modes of action currently on the market.

Management strategies that can slow down or prevent the build-up of resistance are therefore desirable.

Research conducted as part of GRDC investments indicates that many commonly used insecticides are increasingly becoming less effective against key pests such as:

• redlegged earth mite (Halotydeus destructor, RLEM);
• green peach aphid (Myzus persicae, GPA); and
• diamondback moth (Plutella xylostella,DBM).

Cases of RLEM resistance to organophosphates and synthetic pyrethroids have been detected for some time in the western region. However, in 2016, cases of resistance to these chemicals were detected in the southern region.

In these situations, synthetic pyrethroids have become ineffective against RLEM and there is reduced effectiveness of organophosphates.

GPA has evolved resistance to a number of commonly used active ingredients including synthetic pyrethroids, organophosphates and carbamates, but more recently has acquired low-level resistance to neonicotinoids and low levels of resistance to sulfoxaflor in Western Australia.

DBM resistance to synthetic pyrethroids and organophosphates is widespread in Australia and low-to-moderate levels of resistance to avermectins are also common across Australian canola and vegetable production regions.

BCG operations leader Kelly Angel says growers are encouraged to reduce selection pressure on remaining products by using integrated pest management (IPM) tactics and rotating efficacious products.

"Some of the most commonly used insecticides in the southern region aren't selective, which means we are putting constant heavier selection pressure on pests and we are seeing that play out in the form of resistance in RLEM, GPA and DBM," she says.

"As part of this investment we will be producing best management practice guides focusing on RLEM, GPA and DBM.

"These will be built around the current resistance management strategies that exist for these pests, but in a more digestible manner and with a focus on actions so growers know what they should be doing with that information."

Another key output of the project will be a publication summarising the current status of insecticide resistance in crops in the southern region and relative risk of further development based upon pest, farming system and current management practice.

This publication will provide growers and advisers with practical information relating to important natural enemies and beneficial insects and inform decision-making regarding strategic use of insecticides on-farm through IPM strategies.

"This kind of information regarding natural enemies and beneficial insects, or the use of cultural practices for insect management, isn't easy to provide, or in some cases it isn't easy to implement," Ms Angel says.

"However, it's important we get growers and agronomists thinking about and looking for opportunities in order to sustain the use of chemistry for continued cost-effective control of crop pests."

Workshops and sessions at field days across the southern region will also be held to equip growers and advisers with the right knowledge regarding IPM and the important steps to implement a sustainable insect management program.

"Growers are passionate about trying to leave the next generation something that is in better condition than when they started, so making sure all the tools in the box are available for insect management for the future should be a high priority."

More information: Kelly Angel, 03 5492 2787, kelly@bcg.org.au