Cold, windy and wet weather has continued to frustrate a lot of growers by delaying wheat fungicide programmes. But agronomists were still keen that growers took any opportunities this week to apply T0 sprays even with T1 timings fast approaching.
Only about 10% of North Yorkshire AICC agronomist Patrick Stephenson’s scheduled T0s had been applied by Monday (14 April). “We’re on the verge of creating a new timing: T0.5.”
He was not overly worried about the slow start. “The weather has done a fantastic job of holding disease.”
But a further week’s delay would cause some concern, he admitted, particularly for growers with larger areas to cover.
It meant growers should take any chance to spray now, Bill Clark, Broom’s Barn director, agreed. By doing so growers would guard against more serious problems if bad weather delayed T1s, he said. “I’d continue with a triazole plus Bravo.”
Growers are being advised to take advantage of any spray day to apply T0s, even though T1 timing is fast approaching.
He warned growers not to be fooled by thinking tall crops were more forward than they actually were. “Most of the wheats around Broom’s Barn are around GS30-31. They are nowhere near GS32 yet it could be 10-14 days before leaf three is emerging.”
In Kent, crops were more forward, said Charles Ireland of Strutt and Parker. “We could be starting T1s this week in some places, although most will be next week at the earliest.”
All of his T0s had now been applied, with most going on the previous week. “Everything has either had Cherokee at 1 litre/ha, or where we couldn’t get hold of that, a quarter of a litre of Opus plus Bravo.”
Septoria was the real problem this season, he said. “That’s why I’ve been quite aggressive [with my T0s].”
At T1 he was planning to use Proline + Bravo to ensure crops remain clean. “I’m confident of it doing a really good job on septoria. Where I’ve got any varieties with a bit lower eyespot score, I’m doing Tracker. In trials that seems to be leading the way.”
Eyespot was worth looking out for, while brown rust wouldn’t have gone away despite the cold spell, Mr Clark said. “Septoria is the number one, but I would still be thinking about brown rust in the T1 decision. It is still there and as soon as the temperatures warm up it will soon pick up again.”
Mr Ireland was conscious that any warm spell could see crops rush through growth stages after being held back by the cold. “Ideally, I want to apply T1s when leaf three is almost fully out, but if [a spray opportunity] means I’m a little early I’m not too worried, particularly with Proline. I’d rather be early than late.”
Fast-growing crops could cause problems in trying to protect the leaf layers, Mr Stephenson said. “We’re limping along to GS30 at the moment, but you know the flag leaf will be out on 18 May, so there is going to be an explosion of growth at some point. It could be a problem where people think they have a leaf covered when they haven’t.”
His T1 choice would be Proline + Bravo where he had managed to apply a T0. “If not I’m into Opus.”
- Proline – prothioconazole
- Opus – epoxiconazole
- Bravo – chlorothalonil
- Cherokee – propiconazole + cyproconazole + chlorothalonil
Latest fungicide advice:
- Cold has slowed growth and disease
- Continue to apply T0s
- Small interval between T0 and T1
- Septoria main target disease