Excellent establishment and good autumn and early winter growth suggests many winter-sown crops could deliver bumper yields this year. But, with mild weather dominating the autumn and early winter, disease pressure has remained high and some crops may be at risk of lodging.
So careful management – of nitrogen and fungicides in particular – will be needed this spring if early potential is to be fulfilled. “Crop management this season will be completely different,” says David Cairns from McCreath, Simpson & Prentice in Northumberland. “Growers cannot rely on doing ‘what I have always done’. Careful planning will be needed with rates and timing of nitrogen and growth regulators.”
Cereal disease control
Most crops have experienced high disease pressure this autumn, so there is likely to be a large amount of inoculum around in the spring, warns AICC agronomist Dan Dines. “Weather will dictate subsequent development of disease in the spring.”
In Northumberland, high levels of net blotch in barley – particularly Pearl – have been seen, along with mildew and some yellow rust, says Strutt & Parker’s Robert Sullivan. “Fungicide programmes may well have to start sooner and at more robust rates to ensure good initial disease control.”
Growers can take some comfort from the fact that seed dressings such as Baytan (fuberidazole + triadimenol), Redigo (prothioconazole) and Jockey (fluquinconazole + prochloraz) have worked well, adds Mr Cairns. But high levels of diseases in barley and brown rust in some wheat crops means an early “tidy-up” morpholine-based treatment may be needed, he says.
AICC agronomist Ruth East also thinks the level of winter barley disease is likely to justify a spring fungicide with strong net blotch activity. Disease pressure on wheat is also likely to be high, so a T0 fungicide, plus mildewicide and growth regulator, is likely to be required, she says.
“Given the mild, wet weather, we can expect septoria to start getting a grip on most crops through the winter and this will need to be controlled well to maximise crop returns,” adds Devon-based Neil Potts. “Winter barleys are in the same boat as wheat, with many crops showing signs of well-established mildew in late October and early November.”
A mild winter could also increase the take-all risk in second wheats, adds Bedfordshire agronomist Bill Barr, especially those drilled in September or following early September-drilled first wheat. “Assuming we do have some cold weather over winter, the amount of disease in spring will be much more dependent on the weather at the time.”
Cereal lodging and nutrition
Good crop establishment and the mild autumn mean delaying spring nitrogen applications is likely to be a key part of managing increased lodging risk, says Mr Dines.
“It will be interesting to see what soil mineral nitrogen (SMN) levels are like in the spring given the significant rainfall we have had. Nitrogen recommendations will need to allow for the large amount of SMN many crops have already ‘mopped up’.”
Where crops are forward and thick, Mr Barr urges growers to be cautious. “The mild autumn may have led to slightly more mineralisation of soil nitrogen than in an average year. But the amount available to crops will depend on what happens over the next three months in terms of rainfall and temperature.”
Growers should consider reducing nitrogen applied and not rush into the first application, he advises. “Due to the higher lodging risk, a stronger PGR programme may also be required.”
But Countrywide Farmers’ Neil Donkin says that while this is true for early-sown crops, later-drilled crops are showing more normal development. “They may benefit from early nitrogen to increase tiller numbers.”
Early indications suggest pre- and post-emergence autumn treatments have been particularly effective, says Agrovista’s Swaran Bachoo in Hampshire. “However, there have been limited opportunities to apply Atlantis (iodosulfuron + mesosulfuron) in bad blackgrass situations. This treatment will have to be completed as early as possible in the spring to avoid the very large blackgrass we had to tackle last year.”
Mr Barr agrees that residual herbicides have worked well, which may reduce the need for a spring follow-up, but warns that a lack of frosts could lead to a protracted flush of problematic spring wild oats.
Many oilseed rape crops are very forward, increasing the lodging risk and, therefore, the importance of using a growth regulator at green bud stage, such as Caramba (metconazole) or Folicur (tebuconazole), Mr Barr advises. “Nitrogen applications may also be held back a little, although the height of the crop limits how late we can go.”
Nitrogen timing and amount will be critical to get the best from generally good-looking crops, says Mr Potts, who also highlights the potential need for follow-up spring phoma treatments. “We have already seen phoma infection in oilseed rape crops that have received a fungicide, so further control is going to be crucial to maximise crop performance.”
This season’s new oilseed rape pest, turnip sawfly, may also be something growers need to consider in the spring, Mr Dines says. “Larvae from the first generation hatch in June and may then feed on crops at the pod-fill stage, so close monitoring will be needed.”
Look out for Crop Watch reports returning in February after the winter break.