Backward wheat crops will be hardest for fungicide decisions

Disease management of poorer crops is likely to be the trickiest decision for many growers this spring, Tim Whitehead, farm manager at Velcourt’s Vine Farm and host of Cereals 2009, says.


“It is a lot harder to say ‘no’ than ‘yes’ when it comes to fungicides. But if your yield potential is 7t/ha then you want to be spending £30-40/ha rather than £80-90/ha,” he explains.







Cutting back on fungicides does add a lot more risk in those crops, he stresses. “They will need a lot more crop walking, and if yellow rust starts coming in, you might have to spend another £10/ha.”


Typically, the cheaper programme would still be constructed around a three-quarter dose of either Opus or Proline at flag leaf, he suggests. “But everything either side you would question how much and what you are using.”


Fortunately,few of Mr White-head’s crops fall into that lower yield potential category. “Our second wheat has the least yield potential, but it is Hereward, so we are looking at a significant premium over feed with the Warburton’s contract to claw some of that [yield loss] back.”


Indeed, 60% of the farm’s wheat crops have had a T0 this spring. That is down from 90% last spring, but still a significant chunk in a season Mr Whitehead admits has created some crops he is not used to seeing at this point.


“We had some crops only just at GS30 on 15 April, which is unheard of in recent seasons.”


Those late crops are the ones that haven’t had a T0. “The gap has got so short that T0 gets forgotten,” he says.


Earlier-drilled (before 15 September) first wheats, on the other hand, have been treated with Cherokee at T0 in late March. “We were seeing septoria in the bottom of the crop.”







VIDEO BLOG


Would you like to know more about what is going to be demonstrated in the Velcourt plots at Cereals 2009? FWi went to the site armed with a video camera and asked Mr Norman to explain what visitors will see in June.


Log on to www.fwi.co.uk/cereals2009 to see for yourself. 

 


T1s for both will be based on either prothioconazole or epoxiconazole, with Proline being the default treatment, says Keith Norman, Velcourt’s technical director. “We’re picking up lots of stem-based browning, which is why Proline is the preferred option.”


Mildew is another issue worth keeping an eye on, he says. “We’re seeing it in Humber more than anything else at the moment, and we’ve also had our first report of yellow rust in Robigus at a trials site near King’s Lynn.


“I don’t think there would be grounds for anyone to think this is going to be a low disease pressure year – it has just been slow to get going,” he warns.


One concern is product availability. “The just-in-time supply policy has not always been just-in-time. If the season hadn’t been late we might have had to switch products in some cases.”


Fandango (because of the product batch recall) and Filan have been the most affected, he says.


Part of the problem appears to be that some farms have their whole season’s supply on farm already, suggests Bayer’s Gary Jobling. “But we know taking back stock has caused problems.”


Supply of products, such as Proline, is staged to coincide with use periods, he adds. “All product for this year should be with distributors by the end of this month.”


CEREALS  2009



  • New fungicide chemistry will be put under the spotlight in Velcourt’s Cereals 2009 fungicide demonstration, with Bayer CropScience’s new carboxamide, bixafen, being tested in mixture with prothioconazole.
    Visitors will be able to make a direct comparison of the new chemistry versus a strobilurin, fluoxastrobin, with both applied containing the same 0.6 litres/ha equivalent dose of prothioconazole.
    The other key objective of the demonstration is to illustrate the effectiveness of co-formulations of fungicides based on epoxiconazole and prothioconazole.
    All treatments in the trial will only be applied once, at GS33 as in the HGCA appropriate fungicide dose trials, to test protectant activity in the flag leaf and leaf two, and curative activity on leaves emerged at spraying.