A farmers' "herbicide bible" has been updated by industry heavyweight, the Grains Research and Development Corporation (GRDC).

Considered essential manuals in the agricultural industry, 'Soil behaviour of pre-emergent herbicide in Australian farming systems' and 'Understanding post-emergent herbicide weed control in Australian farming systems' were published in 2019 and 2020.

They have undergone a revision to incorporate the latest in herbicide research and practice, including the transition to an international numbering system for herbicide mode of action. This replaced the previous system which used letters for the mode of action.

Greg Rummery, agronomist at Outlook Ag in Walgett said keeping up with changes to herbicides and weed control was essential for the industry.

"The most common changes we see are to registration for use in certain crops and useage rates," he said.

"As an older agronomist, I love having a physical copy of the manual. You can chuck it in the back seat and refer to it wherever you are. The next gen of agros tend to head online first but you can't beat a book in my opinion. It's easy and convenient to just throw in the back of the ute."

Mark Congreve, senior consultant with Independent Consultants Australia Network (ICAN), agreed both manuals are valuable resources for agronomists, researchers and growers. He said they aim to simplify the complex interactions of pesticide chemistry with environmental conditions.

ICAN senior consultant Mark Congreve says updated herbicide use manuals aim to simplify the complex interactions of pesticide chemistry with environmental conditions. (Supplied)

"The manuals provide insights into the behaviour of herbicides under various conditions, the interaction of different products, application techniques, crop safety, and environmental dissipation," Mr Congreve said.

Regulations around chemical application requirements are ever changing.

"Only last year we had the 2, 4-D herbicide label instructions change for safer environmental use," Mr Rummery said. "These new manuals are very useful to keep up with the latest and of course, can be followed up by checking on-line."

According to GRDC Manager Chemical Regulation Gordon Cumming, key updates include the incorporation of new herbicides and modes of action in the pre-emergent herbicide manual.

"These additions highlight the growing range of pre-emergent herbicide options available to Australian growers in managing weed challenges," Mr Cumming said. 

"The post-emergent herbicide manual has seen fewer changes, with minor improvements in understanding certain herbicide modes of action, however, new research improving our understanding of the Group 10 herbicide glufosinate has been included, which is an increasingly important non-selective knockdown herbicide."

Farmers may be interested in the links below.

Download the new 'Soil Behaviour of Pre-Emergent Herbicide in Australian Farming Systems' manual.

Download the 'Understanding Post-Emergent Herbicide Weed Control in Australian Farming Systems' manual.