30 June 2000

Super-strobs on way

STROBILURIN fungicides with super-strob curative activity could be available in two years time, representing a big improvement over current versions, according to initial results from trials of the so-called third generation strobilurins.

"The original ones were only really super-Bravo types, they provided protection only," says Crop Cares Colin Myram. "The newer ones are more like super-triazoles, as they combine protection with curative activity."

In wheat they are being compared with earlier types and conventional triazoles in Savannah. Assessments of disease levels on leaf 4 suggest two of the new batch stand out as having a particularly useful kick-back activity. There was considerably less septoria and better green leaf retention where they had been sprayed.

In Regina winter barley the new strobilurin chemistry is much more effective at controlling disease than triazoles alone at typical rates of nitrogen. At higher rates the differences are even more marked.

"Both look as if they offer more. We need to check the results in the combine tank before we pass final judgement, but I am hopeful there are some very useful improved strobilurin-type fungicides." &#42