3 March 2000

Mildew is no worry, says Dow

REDUCED rates of Fortress (quinoxyfen) do not increase the risk of resistant mildew developing, says maker Dow Agrosciences.

"We do not see that as an increased risk; Fortress blocks a number of pathways in the mildews lifecyle, making it extremely difficult for resistant mutants to occur," says research and development director, Chris Longhurst.

In contrast to strobilurins, rates can be cut to match variety mildew resistance and length of crop protection required. But Dr Long-hurst stresses quinoxyfen is purely protectant and a curative chemical as fenpropimorph should be added to eradicate established disease.

"We prefer to see it used early, at GS30-32."

Match rate to variety


Variety rating Quinoxyfen Weeks

Wheat rate protection

(litres/ha)

4-5 0.3 8

0.2 6

0.1 5

6-7 0.2 >8

0.1 6

Source: Dow AgroSciences.