Valuable integrated
weed management tool

Superior weed control, particularly in tough situations

Annual ryegrass (Lolium rigidum) and wild radish (Raphanus raphanistrum) can be particularly challenging in a winter cropping program with multiple germinations throughout the season which produce high seed populations and are potentially resistant to multiple herbicide modes of action.

Where growers have included Roundup Ready canola in their rotations strong control of both annual ryegrass and wild radish, especially in paddocks where there is confirmed or suspected clethodim resistant ryegrass populations has been achieved.

Monsanto recently compared the weed control of annual ryegrass and wild radish that can be achieved with Roundup Ready® canola, Clearfield canola and Triazine Tolerant canola systems. Multiple trial sites across Western Australia, New South Wales and Victoria were selected for their varying annual ryegrass and/or wild radish pressure and suspected herbicide resistance.
The treatments tested were typical use patterns for the three different herbicide tolerant canola systems:

Roundup Ready canola Roundup Ready Herbicide with PLANTSHIELD® by Monsanto 0.9 kg/ha @ cotyledon to 2 leaf, followed by 0.9 kg/ha @ 4 to 6 leaf.
Clearfield canola 750 mL/ha Intervix® + 0.5% Hasten™ + 500 mL/ha Select® @ 2 to 6 leaf.
Triazine Tolerant canola 1.1 kg/ha Atrazine PSPE followed by 1.1 kg/ha Atrazine +0.5% Hasten™
+ 500 mL/ha Select® + 1.0% Liase @ 2 to 6 leaf.

The study showed Roundup Ready canola offers excellent weed control of the key winter weed species: annual ryegrass and wild radish in paddocks with low to high weed pressure and in the situation of clethodim resistant ryegrass.

Alternative post-emergent chemical group with no residual plant back

The Roundup Ready canola system provides superior weed control and enables use an alternative herbicide group in the early post-emergence phase (Application window: emergence to 6 leaf).

The use of Roundup Ready herbicide with PLANTSHIELD by Monsanto has no residual carry-over into following crops. However, if dual tolerance Roundup Ready/Triazine varieties are grown, triazine residues will need to be considered and crop selection managed to mitigate potential following season crop effects.

Using crop biomass to compete with weeds

Roundup Ready canola hybrid varieties have excellent early season vigour providing greater crop competition for emerging weeds.

Roundup Ready hybrid varieties develop canopy closure faster than non-hybrid canola varieties. Hybrid early vigour  is another key advantage of the Roundup Ready system as increased crop competition reduces the reliance on herbicides to control weeds.