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Weighing up the need for a T0 spray
Date added: 20/02/09 |
Despite the variability of wheat crops, from very forward to very backward, the majority of them will still benefit from a T0 treatment this spring, says Dr. David Ellerton, Technical Director of ProCam.
He acknowledges that some growers are questioning the value of T0 treatments in backward wheats this year, especially with apparent low disease levels.
“Although it may not be needed as much as when crops are lush, thick and advanced, a T0 treatment should be seen as an invaluable insurance spray. It is generally inexpensive, but will reduce disease levels, particularly Septoria, and gives you more leeway to apply the T1 treatment at the right time,” he says.
“If a T0 treatment is not used, T1 timing is often compromised, diseases could be let into the crop and there will be a knock-on effect across the whole disease control programme.”
A T0 treatment has also been demonstrated to give additional yield in its own right, he says.
“The ProCam 4cast agronomy database shows a consistent yield benefit of 0.54 t/ha from a T0 treatment over a number of different years - a good economic response and one that indicates the need for such a treatment every year on the majority of wheat crops.”
“Currently disease levels are low, but when it comes warmer and wetter, diseases will build up rapidly, particular Septoria. So don’t be lulled into a false sense of security, but keep on the ball and be ready to act. Those crops that have the greater potential will require greater investment in fungicides in order to maximise yields and profits,” he says.
David advises that T0 sprays are usually applied between GS 25-30, normally around the end of March, with the T1 spray applied three to four weeks later.
“This year however we need to consider the wide range of growth stages of crops. Backward wheat crops will need a split dose of Growth Regulators - the first split applied at mid-tillering with the second split at Growth Stage 31-32. The first PGR timing is perfect for the T0 treatment and it makes sense to go in with a chlorothalonil based treatment (Bravo/Sonar),” he says.
In the majority of wheat crops which have developed normally, David considers a T0 treatment to be an essential starting point to protecting the crops’ potential.
“The protectant fungicide, chlorothalonil is the base treatment, but you should then tailor what else you might need according to the likely disease risk and the variety being grown. When growing a rust-susceptible variety, you should include a rust-specific component. Options include SAN 703 (chlorothalonil and cyproconazole), Prairie (chlorothalonil and propiconazole), Veto F (tebuconazole) or Menara (cyproconazole).”
“If eyespot is a problem or when growing second wheats, then add in an eyespot specific component such as prochloraz (Poraz). Prochloraz will help reduce Fusarium and there is evidence that it may reduce the selection pressure on some mutated Septoria strains.”
Ends
PRM210
20th February 2009
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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