12 July 2002

T1 strob use vindicated in wheat

KNOCK-ON benefits from applying strobilurin fungicide at the early T1 timing to combat septoria are showing in trials, says manufacturer BASF.

"Advice earlier this season not to back off the T1 treatment has been vindicated," says BASFs Steve Waterhouse. "Where the T2 treatment was delayed the crop was exposed to trouble."

At the companys Huntingdon trials site susceptible wheat variety Tanker was treated with a three-quarter rate of different strobilurin products at the T1 timing, the flag leaf stage or very late at GS55.

"Fungicide applied at T1 appears to have controlled disease before it became established and there is noticeably more green leaf tissue," says Mr Waterhouse. Whether that translates into a yield benefit to cover the extra cost remains to be seen.

Opera (pyraclostrobin + epoxiconazole) kept leaves significantly cleaner than first generation strobilurins, he adds. "It is locally systemic and moves through the leaf sheath to get onto the next leaf to emerge."

Missing the key T2 spray trimming in a bid to stretch fungicide activity also looks like false economy. Visual assessments show a well-timed three-spray programme gave better control than a stretched two-spray approach at GS32 and 55.

Consort trials highlighted the scope for pyraclostrobin-based fungicides to boost yield through better use of available nitrogen.

"The visual differences are at the lower N levels, which suggests Opera is the best fungicide to use to maximise the exploitation of limited amounts of N," says Mr Waterhouse. &#42