Print This PageTrials demonstrate Roundup Ready® canola delivers exceptional weed control and higher yields
Monsanto contracted an independent research provider to investigate the weed control and yield potential of the three different herbicide tolerant canola systems available in Australia (Roundup Ready®, Clearfield® and triazine tolerant).
The trials, conducted at Wallendbeen NSW during the 2009 canola season, were designed to evaluate the performance of Roundup Ready canola at a systems level rather than just comparing varietal performance.
In comparison to most of the Roundup Ready canola trials reported from 2008, this trial was conducted under high weed pressure with approximately 500 ryegrass plants per square meter present in the trial plots. Testing of the ryegrass for resistance prior to undertaking the trial indicated that the ryegrass population was resistant to group B herbicides and therefore likely to impact the performance of the Clearfield system.
Representative varieties for the region from all systems were selected with 3 Roundup Ready varieties (Hyola 601RR, 46Y20 and GT61), 2 Clearfield varieties (46Y78 CL and Hyola 571 CL) and 2 triazine tolerant varieties (Marlin and Tawriffic) being grown in 6 x10 meter plots replicated four times.
The herbicide regime for each of the systems
Roundup Ready
Trifluralin @ 2.1 L/Ha pre-plant followed by 2 applications of Roundup Ready Herbicide @ 0.9 kg/Ha, the first at the 2 leaf stage followed by an application at the 6 leaf stage.Clearfield
Trifluralin @ 2.1 L/Ha pre-plant flowed by Intervix @ 600 mL/Ha + Hasten @ 0.5% + Select @ 250 ml/Ha at the 2 leaf stage.Triazine Tolerant
Trifluralin @ 2.1 L/Ha pre-plant and a pre sowing application of simazine 900 @ 1.1Kg/Ha followed by Atrazine 900 @ 1.1 Kg/Ha + Hasten @ 0.5 % + Select @ 250 ml/ha and 1.0% Liase at 2 leaf stage.
Weed control, assessed by visual comparison to an untreated control, was excellent in the Roundup Ready and triazine tolerant systems with the Roundup Ready providing 95% control of the ryegrass and the triazine tolerant 91% control (Figure 1). Weed control in the Clearfield system was clearly influenced by the presence of group B resistant ryegrass, despite the application of Select (a group A herbicide). Weed control was poor and significantly lower in the Clearfield system then the other systems.
Figure 1. Weed control by variety for the 3 herbicide tolerant canola systems.
The yield results (Figure 2) showed a significant yield increase from Roundup Ready over triazine tolerant varieties, with the Roundup Ready system averaging an 11% yield increase. This is consistent with our previous findings and grower’s experience from 2008. The yield of the Clearfield system was also significantly lower than the Roundup Ready but it is likely that the heavy weed pressure from group B herbicide resistant weeds reduced its yield. This result highlights the benefits of the Roundup Ready system as it provides an alternative canola option in areas with prior weed resistance to group B and other herbicides.
Figure 2. Yield of the varieties of the 3 herbicide tolerant canola systems
Overall, the yield and weed control results from this trial have shown the benefits of the Roundup Ready system. Roundup Ready canola delivers excellent weed control with high yields. Roundup Ready canola can also reduce the pressure on other herbicide groups enabling them to be used for maximum benefit in other parts of the crop rotation.
®Roundup Ready is a Registered Trademark of Monsanto Technology LLC, Monsanto Australia Limited licensee.
® Clearfield is a Registered Trademark of BASF used under licence by Nufarm Australia Ltd
