Optimum growing conditions mean growers will have to be on the ball with pre-emergence herbicide applications, say our Crop Watch agronomists.
Cereal drilling in Gloucestershire started last week and crops were going into good seed-beds, said Countrywide Farmers agronomist Neil Donkin. “Most will be treated pre-emergence with flufenacet mixtures to start off the weed control. But warm, moist soils will cause very rapid crop emergence so they should be applied very soon after drilling.”
Glyphosate could be added to control weeds that survived in the seed-bed, he added.
Some growers were applying a low dose of nitrogen to oilseed rape while temperatures remained high enough for plants to make use of it. “Once we get into October a “fire engine” dose of nitrogen is less effective,” he said.
In Kent, Masstock Arable agronomist Colin Sharp was advising growers with bad grassweed problems to consider fitting in two rounds of stale seed-beds before planting wheat. “Where we can’t do this, we’ll include a compatible glyphosate with some of the pre-emergence sprays to give them a helping hand.”
Good soil moisture meant pre-emergence sprays should give a good start to his programmes. “Wherever we can afford it we’ll be stacking them – using combinations of flufenacet, prosulfocarb, pendimathalin, chlorotoluron and diflufenican – for maximum effect.”
Slugs had not yet appeared, but he was monitoring activity carefully. “We’re keeping our eyes firmly peeled and the pellets to hand. I favour lower dose, hybrid metaldehyde pellets where conditions aren’t too wet and top quality wet pasta-based ones where greater weather resistance is important.”
Concerns over the supply of some pre-emergence products meant UAP agronomist, Will Foss from Cambridgeshire was planning their use carefully. “We are targeting the premium herbicides where they will have the greatest effect and we’re using carefully-considered tank mixes.”
Slug damage was starting to show in later min-till crops on heavier soils, he said. “Hopefully good firm wheat seed-beds after rape where Deter (clothianidin) has been used will take some of the pressure off metaldehyde in these higher risk situations.”
Oilseed rape was generally clean, but at the first sign of disease, a low dose fungicide sould be applied, “Where this is applied early a second treatment may well be required to ensure the crop is disease-free going into winter,” he said. “With oilseed rape prices where they are at the moment a very small yield increase is required to cover the cost of the autumn fungicide programme.”
In Scotland, some growers still hadn’t finished harvest, said AICC agronomist Hamish Coutts from Perthshire. “It’s been a mixed bag. The south is finished with variable yields, the central belt is more or less over apart from some spring oats and beans, but in the north east most of the spring barley and winter wheat is still to cut.”
Oilseed rape crops were growing well, but moist soils meant there had been a flush of volunteer cereals and grassweeds. “These should be taken out with a graminicide soon.”
If pre-emergence herbicides had been missed, growers should opt for an early post-emergence treatment, he added. “A metazachlor/quinmerac mix should suffice, but the old faithful propizamide is always there as a fallback.”
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