Herbicide Resistance of Centaurea cyanus L. in Poland in the Context of Its Management

Abstract

Cornflower (Centaurea cyanus L.), one of the main weeds found among winter crops in Poland, has developed herbicide resistance (HR) to acetolactate synthase (ALS) herbicides, a finding first reported in 2006, and in recent years, farmers have been complaining about inadequate chemical control of this weed. This study aimed to characterise the current state of cornflower HR to ALS inhibitors and synthetic auxins in Poland and the agricultural practices in fields with herbicide-resistant populations. From 2017 to 2020, 159 seed samples together with the field history were collected across the country and biological tests performed in glasshouses. This revealed that 47 populations of C. cyanus were cross-resistant to both tribenuron and florasulam, 28 and 8 populations were single resistant to tribenuron and florasulam, respectively, and 3 populations had developed multiple resistance to both ALS inhibitors and synthetic auxins, i.e., 2,4-D and dicamba. Resistant populations were found mostly frequent in northern Poland, but also in the eastern and western parts of the country. Based on a survey of farmers, the resistant populations were found in winter crops regardless of the tillage system (77% of fields with HR cornflower were mouldboard ploughed). Based on the proposed population treatment (PT) index showing the frequency of herbicide use during three consecutive seasons on farms with HR cornflower, the average PT for all the surveyed farms was 5.4. The highest PT of 7.4 was found in the province of Warmia-Masuria in northern Poland.

Possibilities of Using Seed Meals in Control of Herbicide-Susceptible and -Resistant Biotypes of Rye Brome (Bromus secalinus L.) in Winter Wheat

“…A significant problem in the management of Bromus spp. is the occurrence and evolution of herbicide resistance [ 7 , 38 , 39 ], as a consequence of the limited rotation of herbicides, as well as the application of simplifications to crop rotations and monocultures [ 40 , 41 , 42 ]. Additionally, herbicides pose toxicological and ecological threats, especially toward non-target organisms [ 43 ].…”

Influence of burial depth and soil disturbance on the emergence of common weed species in the Iberian Peninsula

“…], rigid ryegrass (Lolium rigidum Gaudin), and corn poppy (Papaver rhoeas L.) are weed species frequently associated with winter cereal crops in the Iberian Peninsula (Saavedra et al 2016(Saavedra et al , 2017(Saavedra et al , 2018Torra et al 2022). These weeds were selected because the ability of growers to control them is declining due to limited effective herbicide options; in fact, L. rigidum and P. rhoeas have already evolved herbicide resistance in the Iberian Peninsula (Torra et al 2022), as has C. cyanus in Europe (Stankiewicz-Kosyl et al 2021).…”

The impact of burial depth on Centaurea diluta emergence and modelling of its growth using a nonlinear regression and artificial neural network

“…Seedling emergence is particularly important owing to its role determining not only crop interference, but also optimal control timing. Because tillage and seed depth are key drivers of emergence, they can be used to develop integrated management solutions, as has been done in other Centaurea species such as C. solstitialis L., 10 C. cyanus L. 11 and C. stoebe L. 12 Seedling emergence models can help time herbicide use to maximize the number of weeds controlled per application. 13 For this reason, a mathematical model was developed to describe C. diluta seedling emergence, which provided accurate predictions based on soil temperature and moisture.…”