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TRIAZOLES OR STROBS - WHICH IS BEST FOR THE T1 TIMING?
Date added: 18/04/08 |
A good broad-spectrum fungicide based on triazole and applied at a robust rate is what is required at T1 timing in wheat this year, according to ProCam’s Technical Director, Dr. David Ellerton.
The objective of a T1 spray is to protect the top 3 leaves from a range of diseases including Septoria, rusts and mildew as well as protecting the whole plant from stem-based diseases such as eyespot, Fusarium and take-all, he explains.
“Wheat growers should wait until leaf 3 is fully emerged which is usually when the crop is at second node or GS 32. This way you can be assured that Leaf 3 can be fully protected.
“Last year we could get on to spray the crop whenever we wanted in April. This year has not been so easy with the variable weather conditions so products with both protectant and curative activity will be useful.”
Triazoles are the key fungicide group for T1 timing, with the core treatments being based around epoxiconazole and prothioconazole, he says.
“Both actives are strong on Septoria but weaker curatively on rusts, particularly prothioconazole. You need to bring in tebuconazole (as in Veto F) or cyproconazole (Menara) for curative rust control.”
There is much debate on when to use strobs in wheat and Dr. Ellerton is of the view that they are useful but under certain defined situations.
“You can consider including a strob at T1 for rust control or for take-all in second wheats. They also have a place when crops are struggling or are under stress and they need a boost to their rooting and to improve nitrogen scavenging. I don’t consider T1 to be a key timing for strobs in wheat overall. But it is a completely different matter when we come to T2 timing.”
His preferred product choice for T1 in wheat revolves around two strong broad-spectrum options, Capalo or Cello.
“Capalo contains epoxiconazole for a strong Septoria element and protectant rust activity, fenpropimorph for rusts, mildew and some Septoria activity with a different mode of action and metrafenone which brings in eyespot, mildew and it too has some impact on Septoria.”
“Cello also has a strong triazole in prothioconazole, a strong curative element for rusts in tebuconazole which also offers some early activity on Fusarium plus spiroxamine for mildew,” he explains.
“The spiroxamine also appears to improve the overall uptake of the coformulation into the plant. Cello has the edge when it comes to Fusarium and so maybe the choice for quality varieties to aid mycotoxin control.”
In barley the T1 timing is the crucial timing for fungicides and key products are based on the triazole, prothioconazole.
“Cello fits nicely in barley with a good disease spectrum and curative rust control. Another barley option would be Mobius, based on prothioconazole and trifloxystrobin. This is a very good mixture formulation, giving better performance than the individual components,” concludes Dr. Ellerton.
PRM181
18th April 2008
For further information please contact Dr David Ellerton, ProCam Ltd., Royston, Herts. Telephone: 01763 261592
Issued by Philip Hainey, Proterra Ltd., Stamford, Lincs. Telephone: 01780 756299
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