Suppressing Alopecurus myosuroides Huds. in Rotations of Winter-Annual and Spring Crops

Abstract

Alopecurus myosuroides Huds. has become one of the most abundant grass weeds in Europe. High percentages of winter-annual crops in the rotation, earlier sowing of winter wheat and non-inversion tillage favor A. myosuroides. Additionally, many populations in Europe have developed resistance to acetyl-CoA carboxylase (ACCase), acetolactate synthase (ALS) and photosynthetic (PSII) inhibitors. Hence, yield losses due to A. myosuroides have increased. On-farm studies have been carried out in Southern Germany over five years to investigate abundance, control efficacies and crop yield losses due to A. myosuroides. Three crop rotations were established with varying proportions of winter-and summer-annual crops. The crop rotations had a share of 0, 25 and 50% of summer-annual crops. Within each crop rotation, three herbicide strategies were tested. In contrast to classical herbicidal mixtures and sequences, the aim of one of the herbicide strategies was to keep selection pressure as low as possible by using each mode of action (MOA) only once during the five years. A. myosuroides population was susceptible to all herbicide at the beginning of the experiment. Initial average density was 14 plants m −2. In the rotation with only winter-annual crops, density increased to 5347 ears m −2 in the untreated control plots. Densities were lower in the rotations with 25% and even lower with 50% summer-annual crops. Control efficacies against A. myosuroides in the herbicide strategy using only MOAs of the HRAC-groups B and A, according to the Herbicide Resistance Action Committee (HRAC) classification on MOA, dropped after five years compared to the strategy of changing MOA in every year. Nevertheless, the results demonstrate the need for combining preventive and direct weed-management strategies to suppress A. myosuroides and maintain high weed-control efficacies of the herbicides.

Crop Diversification for Improved Weed Management: A Review

“…Ryegrass as a cover crop can help to reduce the emergence of blackgrass by 17%. It can be used as a cover crop in corn, soybean, and winter-wheat [150] Crop rotation of winter-annual and spring crops Five-year rotation with winter wheat, corn, summer barley, winter oilseed rape, and winter wheat reduce blackgrass densities by 50% as compared to winter wheat and winter oilseed rape rotation [151] Weed Species = Rigid Ryegrass (Lolium rigidum)…”

Effect of winter cereal sowing time on yield and nitrogen leaching based on experiments and modelling

“…These simulations do not reflect the increased sensitivity of the early-sown wheat to weed infestations, such as black grass (Zeller et al, 2018). Due to the short time period between harvest or the previous main crop and sowing of the next winter wheat, early sowing leaves only a short time for weed control.…”

“…While this can be overcome with an increase in the use of pesticides, this is in disparity with the European Union policy to reduce pesticide use (Moss, 2017). Furthermore, the development of resistant weed populations has been observed (Zeller et al, 2018). Another problem with early sowing is the risk of increased lodging with early sowing which comes as an economic cost due to lower yields, delayed harvest, poor grain quality and the need for greater grain drying (Griffin, 1998).…”

Exploring the Effects of Different Stubble Tillage Practices and Glyphosate Application Combined with the New Soil Residual Herbicide Cinmethylin against Alopecurus myosuroides Huds. in Winter Wheat

“…Densities of around 100 A. myosuroides plants m −2 cause grain yield losses of 20% in winter wheat [11]. If not sufficiently controlled, populations can rapidly increase to densities of more than 1.000 plants m −2 [12]. To prevent population increase, a control efficacy of minimum 95% is required [9].…”