Cultural tactics and accurate spraying essential for e ective wild oat control

“Brome problems also seem to be on the increase, often associated with changes in tillage practice.

…from previous page on many farms. Around here, it seemed to rst appear on sandier clay loams – but is now seen on heavier soils, too. It seems to come through autumn residuals fairly well and has a deep taproot, so it can cause lots of problem.” He recommends targeting the weed early with sulfonyl ureas, ideally supported with another mode of action such as a hormone.

“Brome problems also seem to be on the increase, often associated with changes in tillage practice. In winter wheat, there are in-crop products such as Paci ca Plus (mesosulfuron + iodosulfuron + amidosulfuron), but limited options in other crops. However, longer term, farmers need to be looking at which species they have and analysing the life-cycle to get more out of cultural controls.”

Agrovista agronomist Chris Martin is optimistic after a successful autumn. “It’s an exciting season – with good crop potential and prices, we can make serious money for farmers this year, but disease and growth regulation are going to be key.

“It’s the best residual performance I’ve seen for several years; conditions and soil moisture were ideal. Proclus (aclonifen) and Liberator ( ufenacet + di ufenican) have been phenomenal. The right chemistry with the right application has been very successful. Flat fan nozzles have performed noticeably better than air inclusion.”

Because of the upfront cost of fertiliser and crop protection, Mr Martin thinks some farmers will be tempted to trim fungicide or herbicide costs and prioritise fertiliser. “It’s a tricky one. I understand the desire to cut costs, but you don’t want to lose crop potential. If people have weedy patches with less serious weeds, I can see why you might drop a post-em treatment. If there’s black-grass, it doesn’t make sense to skip further treatment because it saves up problems for future seasons.”

Mr Martin notes an increase in brome issues alongside the usual grassweed problems of wild oats, black-grass and some ryegrass. Among the broad-leaved weeds, cranesbill, groundsel and cleavers are quite common this season. “I expect on elds with a mixture of grassweeds we will be following up with a Paci ca Plus, or Horus (mesosulfuron + iodosulfuron)-type products.”

Turning to spring crop establishment, spraying o before drilling is the next task according to Agrii’s Mr Felce. “There are di erent situations in spring – if there is no cover crop, just a cultivated stubble, the main problems are likely to be grassweeds without any shading canopy. In this situation, one good application of glyphosate before drilling is likely to be enough,” he reckons.

“Timing depends on the size and density of weeds, but you need to leave enough time for biomass above and below ground to die o to help ensure a good natural tilth. Sometimes, black-grass can form thick mats of weedy turf which is not a good seedbed, so be aware of this.

“With cover crops, there is likely to be a canopy with lots of biomass shading some smaller grassweeds. In this instance, two applications might be needed; the rst to kill the cover crop, the second to kill the grassweeds. Higher rates are likely to be needed to kill over-wintered cover crops, but grassweeds are likely to be quite small, so the second application will use a lower rate.

“From a stewardship angle, I think two hits with glyphosate is the most we should use before autumn and spring crops.” FG

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