Don’t overlook the need for sulphur on cereal crops
Most winter cereals are due nitrogen at their early stem extension stage, according to CAFRE Crops Advisor Leigh McLean.
Barley normally reaches this stage ahead of wheat, he said.
“If not already applied aim to include sulphur at a total rate of 25-40kg/ha of sulphur trioxide equivalent for all cereals, remembering that applications of organic manures will have supplied some of this requirement.
This spring, do not underestimate the nutrients from autumn-applied manures.
“Lower than normal winter rainfall means there is less likelihood that nutrients, such as nitrogen and sulphur, have been leached out of the root zone.
“In many cases these should still be readily available to winter crops,” he added.
McLean said that crops should be inspected for any recently emerged broad-leaved weeds.
“Top-up herbicide should be applied as soon as conditions allow. As with all pesticides, there must be full adherence to product labels with operators paying particular attention to latest application timings, sequences with other herbicides and approved tank mixes with other products.”
According to McLean, the relatively mild and good growing winter has resulted in thick crops of winter barley and generally high levels of foliar disease.
“Mildew and rhynchosporium are widespread and, where infection is severe, keep fungicide rates high – particularly where T0 fungicide was not applied or T1 has still to be applied.
“Apply the follow-up T2 fungicide about when the flag leaf has fully emerged and the first few awns are appearing – no later than four weeks from the T1 timing. At both T1 and T2 timings, best performance is achieved with an SDHI or prothioconazole in the product mix.
Strobilurins and other azoles aren’t as strong, but still offer useful protection in mixes where crops are clean or disease pressure is lower.
The CAFRE advisor confirmed that, by now, some winter wheat has received a T0 fungicide.
“Where this has not been applied, the T1 will be critical to get on top of septoria and should be applied ideally when leaf 3 is emerging.
“For the T1 use robust rates of Triazole, mixed with an SDHI and multi-site protectant. Mildew is easily found in all cereals this year and, if present, add a specific mildewicide to the tank mix at the next fungicide timing,” he said.
McLean said that many winter cereals, particularly barley, are thick and pose a high lodging risk.
“If so, early stem extension is the most effective timing to shorten straw; so include a plant growth regulator with T1 fungicides. For thick, early-sown winter barley a split application may be necessary – ideally at T0 and T1,” he added.