TY  - THES
T1  - Incorporating agronomic measures into integrated weed management strategies using pre-emergence herbicide cinmethylin to control Alopecurus myosuroides Huds.
A1  - Messelhäuser,Miriam
Y1  - 2022/02/23
N2  - Alopecurus myosuroides Huds. is one of the most problematic grass weeds in cereal production in Western Europe. This grass weed spread rapidly due to the repeated and intensive use of herbicides with the same mode of action and changes in arable cropping and tillage systems. Herbicide applications are the common agricultural practice for successful control of A. myosuroides due to its high flexibility and low cost. However, due to European and national restrictions and the growth of herbicide-resistant populations, farmers are forced to reduce herbicide use to minimize chemical impacts on the environment and food chain. As a holistic approach for reducing herbicide use, integrated weed management (IWM) is a diversification of the control strategy of A. myosuroides. In this thesis, several aspects of IWM were examined and combined to test for a successful A. myosuroides control strategy in winter cereals. Special attention was paid to cinmethylin, a pre-emergence herbicide with a new mode of action in winter cereals to control A. myosuroides. 
The first article comprised the development of an agar bioassay sensitivity test to determine sensitivity differences in A. myosuroides populations to pre-emergence herbicides containing flufenacet and the re-discovered substance cinmethylin. All of the tested populations did not show reduced sensitivity to cinmethylin, but differences in resistance factors were observed between the agar bioassay sensitivity test and the standard whole plant pot bioassay in the greenhouse. Nevertheless, it was possible for the most part to confirm the results for cinmethylin and flufenacet of the standardized greenhouse whole plant pot bioassay in the agar bioassay sensitivity tests and hence create a reliable, faster test system. 
The second article focused on cultural measures like cover crop mixtures, various stubble tillage methods and glyphosate treatments and their effect on total weed infestation in particular on A. mysouroides and volunteer wheat. Within two field experiments, the cover crop mixtures and the dual glyphosate application achieved a control efficacy of A. myosuroides of up to 100%, whereas stubble tillage and the single glyphosate treatment did not reduce A. myosuroides population significantly. The results demonstrated, that besides a double glyphosate application, well developed cover crop mixtures have a great ability for weed control, even for A. myosuroides.
The third article also dealed with the combination of cultural measures (delayed seeding) and herbicide application and their influence on A. myosuroides control efficacy and yield response of winter wheat and triticale. Results indicate that cultural methods such as delayed seeding can reduce A. myosuroides populations up to 75%, although to achieve control efficacy of > 95%, supplementary herbicides should be used. 
In the fourth article, a two-year experiment on two experimental sites was set up with a special focus on stubble tillage methods, glyphosate application and the application of the pre-emergence herbicide cinmethylin in two rates. Control efficiencies of 99-100% were achieved by ploughing, double glyphosate application or via false seedbed preparation, each in combination with a cinmethylin application. 
In the last article, over a period of three years the new pre-emergence herbicide cinmethylin was tested in combination with stubble treatments and delayed drilling of winter annual cereals in winter wheat and winter triticale in Southwestern Germany. Cinmethylin controlled 58-99% of A. myosuroides plants until 120 days after sowing. Additive and synergistic effects of cinmethylin and delayed drilling were found for all studies. 
In this study, the focus was set on monitoring, cultural and direct weed control methods. Considering especially A. myosuroides, a diverse control strategy needs to be implemented to ensure a sustainable and reduced herbicide use, high control levels, minimized crop damage, safeguarded grain yields and reduced risk of resistance development. However, IWM measures imply increased system complexity, which may make their adoption by farmers difficult. Nevertheless, the results show that cinmethylin can be successfully used for weed control systems in combination with different stubble tillage methods, glyphosate application, delayed seeding, or herbicide sequences and mixtures, making it a valuable tool in integrated weed and resistance management strategies with its novel and unique mode of action.


KW  - Unkrautbekämpfung
KW  - Herbizid
KW  - Integrierte Unkrautbekämpfung
KW  - Herbizidresistenz
CY  - Hohenheim
PB  - Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim
AD  - Garbenstr. 15, 70593 Stuttgart
UR  - http://opus.uni-hohenheim.de/volltexte/2022/1992
ER  -