New tools help YP growers keep pressure on grasses
- Grower Stories
21 April, 2016
- Grower Stories
21 April, 2016
Extending cereal cropping rotations and adopting a new pre-emergent herbicide option in lentils, in conjunction with employing other management strategies, is set to further help Yorke Peninsula growers to drive down grass weed numbers.
Zack Zweck, who has been working as an agronomist in the region for the past six years with AW Vater and Co at Kadina, said annual ryegrass control had proved difficult for growers, particularly in canola, which, consequently, had been removed from various cropping programs.
“The area has had a strong history of trifluralin (herbicide) use and there is now a high resistance level, and we don’t have in-crop solutions,’’ Zack said.
“However, growers who are getting a third cereal into their rotations, and who are now using Sakura® (Group K pre-emergent herbicide), are getting lower grass populations.
“Prior to Sakura, they were using Boxer Gold® for the length of residual (protection), then Sakura came in and has been used on the wheat, and they can use Treflan®/Avadex® Xtra for the third cereal.
“Sakura adds some flexibility for the spraying and sowing operations compared with Treflan, it has good effect with stubbles and its length of residual control far outweighs anything else, which was a real eye opener. Boxer Gold and Treflan/Avadex lasts for about six weeks, but then you can get another flush (of grass weeds).’’
Zack said brome grass was also increasingly coming on the radar for growers and, fortunately, Sakura provided good suppression of this grass weed, whilst including Avadex Xtra in a mix with Sakura was suitable for paddocks with wild oats.
In encouraging growers to rotate their herbicides each season, he said they could use Sakura, then Boxer Gold and then Treflan/Avadex for consecutive cereal crops, or grow a legume crop in the third year of the rotation.
Bayer Territory Sales Manager Graham Hatcher said to help ensure the longevity of the Group K herbicide for growers, they should use it no more than twice every four years in the same paddock.
Containing the active ingredient, pyroxasulfone, Sakura controls annual ryegrass, barley grass, silver grass, annual phalaris and toad rush and also suppresses certain grass weeds in wheat (not durum wheat), triticale, chickpeas, field peas and lupins.
It has also recently been registered for use in lentils, which is a major bonus for growers on Yorke Peninsula, one of the biggest lentil production areas in Australia.
Zack said over the last two years, lentils, which performed well on alkaline soils, had become one of the major crops grown. He estimated about 40 per cent of the peninsula’s crop production was devoted to lentils. Graham said it amounted to about 85,000 hectares.
“Wheat-barley-lentils or wheat-wheat-lentils are popular rotations,’’ Zack said.
In conjunction with Bayer, AW Vater and Co has coordinated fully replicated trials of Sakura in lentils over the past three years, with farmer demonstration trials also occurring the last two seasons.
Zack said Sakura was compared with farmers’ standard applications.
“By using Sakura in lentils to take out the early flush of grass weeds, Select® (post-emergent herbicide) will then work better and, importantly, it will be clean for the next crop.’’
He said growers could also include a triazine type broadleaf herbicide with Sakura, particularly since lentils offered poor early crop competition.
The trials are set to continue in the coming season.
Meanwhile, Zack said growers were also applying knockdown sprays in their programs and employing other integrated weed management (IWM) strategies in an effort to control grass weed populations.
“There is still a lot of hay grown and we are now seeing more wheaten hay. Hay was a way to get numbers down quickly – and we are fortunate to have exporters here and in the Mid North.’’
He said various growers also crop-topped to control weed escapes, used chaff carts and burned windrows after lentil crops.