2022

We have previously demonstrated that an aldo-keto reductase (AKR) from Echinochloa colona (EcAKR4-1) can metabolize glyphosate and confers glyphosate resistance. This study aims to investigate if the EcAKR4-1 orthologs from Lolium rigidum also play a role in glyphosate resistance in non-target-site based, glyphosate-resistant (R) L. rigidum populations from Western Australia.

Experiments were conducted to evaluate the single effect of soybean competition and its combined effect with a glyphosate field dose (1,080 g a.e. ha-1) on the growth and fitness of plants carrying glyphosate resistance endowing target site mutations.

We report here the first case of field resistance to HPPD-inhibiting herbicides in R. raphanistrum (wild radish), caused by 12 years of continuous reliance on that mode of action.

Cinmethylin, a pre-emergence herbicide inhibiting fatty acid thioesterase activity, has recently been introduced to Australian cereal cropping for the control of Lolium rigidum Gaud. (annual ryegrass). To date, there have been no confirmed cases of cinmethylin resistance identified in this species, but some populations exhibit reduced sensitivity to this herbicide.

This study evaluates the interaction among developing herbicide resistance, seed size and seed dormancy of ripgut brome, wild oat and hare barley collected from within intensively-managed fields (in-crop) in comparison with populations in surrounding ruderal (non-crop disturbed) areas with no history of exposure to herbicides within the Western Australian grainbelt.

This paper reviews the reproductive biology, herbicide-resistant biotypes, pollen-mediated gene flow (PMGF), and potential for transfer of alleles from herbicide-resistant to herbicide-susceptible grass weeds including barnyard grass, creeping bentgrass, Italian ryegrass, Johnson grass, rigid (annual) ryegrass, and wild oats.

Lolium rigidum is the most important weed in Australian agriculture and the pre-emergence dinitroaniline herbicides (e.g. trifluralin) are widely and persistently used for Lolium control. Consequently, resistance evolution to dinitroaniline herbicides has been increasingly reported. Resistance-endowing target-site 𝛼-tubulin gene mutations are identified with varying frequencies. The present study investigated the putative fitness cost associated with the common resistance mutation Val-202-Phe, and the rare resistance mutation of Arg-243-Met causing helical plant growth.

Long-term and excessive herbicide use has led to some environmental concerns and especially, herbicide resistance evolution in weeds. Here, researchers confirmed acetolactate synthase (ALS) inhibiting herbicide penoxsulam resistance and cross-resistance to acetyl-coenzyme carboxylase (ACCase) inhibiting herbicides (cyhalofop-butyl and metamifop) in a global weed Echinochloa crus-galli population resistant to these herbicides (R).