Changes afoot in cereal fungicide programmes
Changes afoot in cereal fungicide programmes
Chilly dry weather looks set to spur cereal
disease control adjustments on farmers weeklys
barometer farms. Andrew Blake reports
WITH T1 treatments delayed for various reasons, the opportunity to modify spray programmes and maybe economise is greater than usual.
That is the feeling from the south-west to the north, where the only wheat treatments before the middle of last week had been against mildew and to provide vital manganese.
Cold winds and frosts preventing spraying have been the norm. Crop growth has slowed and disease levels are generally very low. But eyespot in the east could still be troublesome and there is a notable absence of complacency.
"There is a lot of septoria in the bottom of our wheat and things could change very rapidly," says William Hemus in Warks.
Chris Salisbury in Somerset agrees. "When the weather breaks we are more than likely to get a good soaking which will be ideal for septoria splash events."
In Yorks, T1s were still awaited last week. "I want to be at GS31/32 rather than GS30/31 before applying my T1," says BASIS-qualified Catherine Thompson.
"If we go too early the chemical could run out of steam before flag leaf and force us into a three-spray programme. Everybody expected crops to rush through their growth stages, but its not happening."
Winter wheat programmes at Holme House, where budget fungicide spend is about £50/ha (£20/acre), are strongly linked to soil type, variety and drilling date.
But prices, which vary considerably between suppliers, are also a key influence. Only on the heavy land is a T3 ear wash normally required.
"Its too early to say if we shall be able to make any overall savings," says Mrs Thompson. Early sowings definitely needed pre-T1 mildewicide Fortress (quinoxyfen) against mildew which is also ravaging early drilled winter oats.
Basic T1 for her early sown Claire on heavy land and Consort after roots is 0.6 litres/ha of Landmark (epoxiconazole + kresoxim-methyl). But early drilled more disease-susceptible Consort on light and medium soils merits 0.6 litres/ha of Acanto (picoxystrobin) + 0.25 litres/ha of Opus (epoxiconazole), she believes.
"The Acanto mix costs about £4/ha more and we dont need a particularly high yield response to pay for it. But £4 is still £4, which might be better spent on a more expensive strob like Opera, which I want to try at T2 on the earliest Consort where disease pressure is likely to be highest."
Landmark is about 50p/ha cheaper than last year, she says. But there are even bigger savings to be had by shopping around. "The difference in price for some strobs is up to £5/litre."
Several manganese treatments to boost her light land crops disease defences and counter stress from drought and free-living eelworms have been applied.
"They are absolutely essential on our sands. Weve used a full rate of manganese sulphate in the autumn and another full and two half rates already this spring."
She has only one field of second wheat so eyespot is of little concern. But basal stem staining on Pearl winter barley has been treated. *
DISEASECONTROL
• Cold dry weather helping.
• Potentially less expense.
• Still early days for septoria.
• Dose cuts main reaction.
• South-west
Somerset grower Chris Salisbury anticipates little change in his overall strategy, though product doses are likely to be trimmed on clean-looking crops.
All wheats which had a pre-T1 of necessity will get two more sprays as will most of his other crops.
"But we still have some very backward crops. The rolling we tried (Arable, Mar 22) did no good whatsoever, and if conditions arent conducive to disease there might be some scope for reducing rates. But there is still a long way to go."
• East
The longer dry weather continues in Essex, the greater the room for fungicide savings, says Peter Wombwells agronomist Paul Johnson. "We have been holding on for leaf three to emerge and shall be paring rates back a bit."
Diagnostic tests have found plenty of eyespot in Mr Wombwells second wheats and levels worth monitoring in first crops, he notes. "So we might have to spend a bit more than we expected. But it may not develop if it stays dry."
• West
In Shropshire, Sandy Walker hopes two-spray tactics, as normal, will suffice for most of his wheats, especially with a robust T1 based on new product Opponent (pyraclostrobin + kresoxim-methyl + epoxiconazole) on the advice of Agrovistas Neil Buchanan.
"We are playing safe," says Mr Walker. "There is still a lot of potential for disease." Follow-up treatments will depend very much on the weather.
• South
Late-sown, N-fed wheats have overtaken earlier sowings which stood still in the cool weather, says Surrey-based Giles Porter. But with little disease about he does not expect to be into T1s until after the weekend. Plans could still be modified, but are expected to be based on triazole Flamenco (fluquinconazole) with quinoxyfen or chlorothalonil depending on variety. But potential premium earners will get Twist (trifloxystrobin)/Opus mix.