Introduction of a Nondestructive Method for the Investigation of Herbicide Efficacy in Greenhouse Bioassays Based on Image Analysis
- Publication Type
- Contribution to conference
- Authors
- Ortrud Jaeck and Alexander Menegat and Martin Weis and Hanwen Ni and Roland Gerhards
- Year of publication
- 2011
- Published in
- 23rd Asian-Pacific Weed Science Society Conference -- Weed Management in a Changing World
- Conference name
- 23rd Asian-Pacific Weed Science Society Conference
- Conference location
- Queensland, Australia
- Conference date
- 26.--29. Sep. 2011
The North China Plain (NCP) is the main winter wheat growing region in China. In winter wheat, Bromus japonicus is a typical annual monocotyledonous weed, which is difficult to control and causes high yield losses as a consequence for lack of effective herbicides. For this reason dose-response studies were conducted in a greenhouse to test the efficacy of several herbicides on B. japonicus. Two ACCase inhibitors, five ALS inhibitors and one PS(II) inhibitor were tested at six different application rates. Efficacy on B. japonicus was measured by dry weight assessment as well as non-destructive by leaf coverage measurements with a bi-spectral camera. The efficacy of the tested ACCase and PS(II) inhibitors was not satisfying, even at high dosages. However the tested ALS inhibitors showed high efficacies. Coverage measurements with the bi-spectral camera correlated very well with the dry matter weight of B. japonicus. Therefore it can serve as an easy, rapid and non-destructive method to determine herbicide efficacy over time and also under field conditions. It is necessary to introduce new herbicides to the NCP for an efficient weed control, regarding the security of national food supply. Therefore comprehensive dose-response studies are necessary to test many herbicides with different modes of action on all important weeds of the NCP.