Rotate to reduce resistance
GroundCover™ Supplement Issue: 104 | 06 May 2013 | Author: Abul Hashem
Growers in the southern cropping region can learn from the experience of their western counterparts to slow the development of herbicide-resistant wild radish, which has developed widespread multiple resistance to herbicides in Western Australia
Rotating crops and herbicides with diverse modes of action can slow the build-up of wild radish with resistance to acetolactate synthase (ALS) herbicides (Group B herbicides), according to GRDC-funded Department of Agriculture and Food, Western Australia (DAFWA) research.
In a four-year field trial at Beverley in the central WA wheatbelt, researchers compared the impact of a conventional and alternative crop rotation treated with either a high or low frequency of ALS applications on the resistance dynamics of a ryegrass population with an initially low level of resistance to ALS inhibitors (Table 1).
The number of wild radish plants with ALS resistance increased exponentially following repeated application of ALS herbicides in a continuous wheat-lupin rotation over four years (Figure 1).
Introducing TT canola into the wheat-lupin rotation and applying auxinic herbicides in the wheat crop and triazines in canola resulted in complete radish control and no build-up of ALS-resistance over the four-year trial.
Competition from the resistant wild radish in the conventional rotation reduced wheat and lupin yields by about two-thirds of those in the TT-canola rotation.
Abul Hashem, DAFWA,
08 9690 2000,
GRDC Project Code DAW535
Region West, South
Was this page helpful?