Higher levels of Septoria have been confirmed in wheat crops this spring – most likely brought on by earlier drilling.
Active infections of Septoria tritici have been detected even in varieties with good resistance where these were drilled early, according to ProCam. Varieties with resistance ratings below six are particularly vulnerable.
ProCam agronomists say the disease is not just confined to lower, older leaves. It is also being found on the next layer of younger leaves – which means it could spread higher up the plant when it rains and start damaging yield.
Many growers drilled wheat early last autumn with seed left over from the previous year when wet weather made it impossible to get crops in the ground later, says ProCam head of crop production Mike Thornton (pictured right).
“Good Septoria tritici control from early-season fungicides is set to be particularly important to halt its spread onto higher yield-building leaves – especially now we no longer have the stalwart fungicide, chlorothalonil, against the disease.”
Mr Thornton says specific T0 fungicide options will vary depending on other diseases present. Although some new fungicide chemistry has curative ability, he believes it could increases the risk of resistance.
“There is an argument that says you don’t get a yield increase from controlling Septoria at the early T0 fungicide timing. That’s fine if you can guarantee you’ll be able to apply later sprays exactly on time. But very often you can’t.”
Mr Thornton says he generally looks to include a multi-site treatment against Septoria of folpet – and potentially an azole if active yellow rust needs controlling, or a strobilurin for protection if yellow rust is a threat.