Approach to Demography of ALS-Resistant Glebionis coronaria as Influenced by Management Factors: Tillage, Allelopathic Crops and Herbicides

Abstract

Glebionis coronaria (L.) Cass. ex Spach is one of the most serious weeds in cereal crops in Northern Tunisia. Our previous studies have confirmed the presence of resistance to ALS-inhibiting herbicides in G. coronaria, showing the evolution of cross-resistance through TS and NTS mechanisms. The purpose of this study was to evaluate the effects of (i) two tillage practices (conventional tillage and reduced tillage), (ii) three known allelopathic crops: Hordeum vulgare L. (Barley), Brassica napus L. (Rapeseed) and Triticum durum (Wheat) and (iii) herbicides belonging to different modes of action on the density, the cohort numbers and the growth of an ALS-inhibiting cross-resistant population of G. coronaria. Field experiments were conducted in two consecutive years (2017–2018 and 2018–2019) in the Fritissa-Mateur-Bizerte region. Our results revealed that barley considerably contributed to the decrease in G. coronaria’s density, cohort number, total biomass accumulation and plant height. The effect of rapeseed is likely dependent on the tillage practice and the timing of herbicide application, while G. coronaria could be successfully controlled in wheat using auxin herbicides. It is suggested that the management of resistant population of G. coronaria could be achieved by combining barely or rapeseed with right tillage practice and auxin herbicides’ application.

Pro197 and Trp574 substitutions in the acetolactate synthase of corn marigold (Glebionis segetum) and their impact on competitive ability against barley

“…In contrast to these results, Hada et al (2020) found that the co-mixtures of aminopyralid + florasulam + 2,4-D and aminopyralid + florasulam provided lower efficacy (85%) against crown daisy than that obtained in our study and by their application of co-mixtures synthetic auxin herbicides 2,4-D + MCPA and dicamba + 2,4-D (respective efficacy of 92% and 94%). In addition, Hada et al (2022) found in another field study that the application of 2,4-D + florasulam on cereals and clopyralid on rapeseed reduced crown daisy densities by 44%, 75%, and 66% in wheat, barley, and rapeseed, respectively, whereas the respective reduction due to dicamba + 2,4-D was 85% and 91% in wheat and barley growth. These efficacy differences could be attributed to differing activity between the synthetic auxin herbicides, differing compatibility in co-formulations with ALS inhibitors, differing susceptibility among the R populations to these herbicides, differing competitive or allopathic ability of the crop species against the weed populations, and differing environmental conditions prevailing during the experiments.…”

“…Control of corn marigold in winter cereals relies mainly on acetolactate synthase (ALS) inhibitors applied either alone or in mixtures with synthetic auxins (Hada et al 2020(Hada et al , 2021(Hada et al , 2022. Unfortunately, ALS-inhibiting herbicides are the most prone to rapid evolution of target site-mediated resistance, which, in most reported cases, is conferred by a single missense mutation in the ALS gene (Yu and Powles 2014).…”

“…The most detected amino acid substitutions conferring ALS resistance are those affecting Pro-197 and Trp-574 (Beckie and Tardif 2012; Yu and Powles 2014). The synthetic auxin herbicides, having a mode of action similar to the endogenous plant hormone indole-3-acetic acid, are also applied in winter cereals either alone or as mixtures with ALS-inhibiting herbicides for the control of broadleaf weeds, helping to slow the appearance and spread of ALS-resistant weed populations (Hada et al 2022; Ntoanidou et al 2017, 2019; Rosario et al 2011).…”