Herbicide resistance in weeds, including corn poppy (Papaver rhoeas L.), is an increasing problem compromising global crop production. The aims of this study were to evaluate the susceptibility of P. rhoeas populations in Poland to acetolactate synthase (ALS) inhibitors and elucidate their mechanisms of resistance. Between 2017 and 2020, 157 seed samples were collected nationwide and a dose-response study with various ALS-inhibiting herbicides was performed in glasshouses. This revealed 14 resistant populations with R/S ranges of 2.3–1450.2, 9.5–398.5 and 2–2.5 for tribenuron, iodosulfuron and florasulam, respectively. Eight of them were cross-resistant to both tribenuron and iodosulfuron, three and one populations were singly resistant to tribenuron and iodosulfuron, respectively, and one population had reduced susceptibility to florasulam only. In one population, cross-resistance to tribenuron, iodosulfuron and florasulam was identified. The ED50 of many populations susceptible to ALS inhibitors was close to half the recommended dose of the herbicides tested. In seven out of eight resistant P. rhoeas populations analysed, target-site resistance was identified. Six amino acid replacements were found (Ala197, Arg197, His197, Leu197, Ser197 and Thr197). In one population resistant to ALS inhibitors, no mutations in the ALS gene were detected. An efficient anti-resistance strategy is needed to reduce the development of herbicide resistance in P. rhoeas in Poland.

The effectiveness of reclamation activities in a tailing pond has been evaluated by the application of mineral and organic substances and remediation plants with water absorbing geocomposites. The research was conducted on the tailing pond of the former copper mine in Iwiny, Poland, basing on a strict, trifactorial experiment set up with the use of the split-split-plot method with 4 replications. The main experimental factors were the variants of substrate modification, various species (or mixtures) of reclamation plants and the presence of water absorbing geocomposites. The conducted experiments did not demonstrate a significant influence of various types of tailing additives. The usability of individual species of reclamation grass or their mixtures for the reclamation was similar. Water absorbing geocomposites contributed to the improvement of difficult vegetation conditions that occur in tailing ponds.

Blackgrass (Alopecurus myosuroides Huds.), one of the most aggressive grass weeds in Europe, is also a strong competitor of crops. This study aimed to assess the impact of environmental conditions on the competition between (1) ACC-ase and ALS herbicide-resistant (BR) and herbicide-susceptible (BS) blackgrass biotypes, (2) BR and winter wheat cv. Arkadia (W), and (3) BS and W. In the replacement series model, the experiment was conducted at seven sites across Poland during two seasons (2018/19 and 2019/20). In the BR-BS experiment, the BS biotype was in majority more competitive toward the BR biotype. However, in the regime of optimal hydrothermal conditions and at a higher sand content in the soil we observed a higher competitiveness of BR towards BS. The combined interactions between W and BR or BS were also affected by environmental conditions, i.e., soil texture and hydrothermal coefficient, as explained by PCA and k-means cluster analysis. At most sites, W was more competitive toward both BS and BR, which could result from earlier emergence of W in relation to B in majority of sites. Except for two cases, located on heavy, clay soils, during humid seasons, where B was more competitive toward W. We summarize that blackgrass competitiveness towards other biotypes and wheat depends to some extent on environmental conditions; however, the phenomenon should be explored in more detail.

Non-reclaimed flotation waste deposits created as a result of copper ore mining are harmful to the environment for many reasons. They contribute to water pollution and blowing out dust containing heavy metals, which may cause soil contamination and negatively affect the development of vegetation in their vicinity [1]. Due to the technology used in ore processing, flotation waste is characterised by a high share of very fine particles (usually around 85%) and a very small share of skeletal parts, which has a negative influence

Blackgrass (Alopecurus myosuroides Huds.), one of the most aggressive grass-weeds in Europe, is also a strong competitor of crops. This study aimed to assess the impact of environmental conditions on the competition between 1) herbicide-resistant (BR) and susceptible (BS) blackgrass biotypes 2) the BR and winter wheat cv. Arkadia (W), and 3) the BS and W. In the replacement series model, the experiment was conducted in seven sites across Poland during two seasons (2018/19 and 2019/20). The competitive ratio (CR) was calculated for the relative biomass of plants and grain number. If CR < 1, the blackgrass is more competitive toward winter wheat, if CR > 1, the wheat is more competitive toward blackgrass. In the BR-BS experiment, the BS biotype was more competitive toward the BR one. We also found that the competitiveness between BR and BS was related to sand content in the soil. The combined interactions between W and BR or BS were also related to environmental conditions, i.e., soil texture and hydrothermal coefficient, as explained by PCA and k-means cluster analysis. In most sites, W was more competitive toward both BS and BR. Except was for two cases, located on heavy, clay soils, during humid seasons, where B was more competitive toward W. We summarize that blackgrass competitiveness towards other biotypes and wheat depends on environmental conditions; however, the phenomenon should be explored in more detail.