POTATO GROWERS using strobilurin fungicide Amistar (azoxystrobin) to control blackdot or rhizoctonia in potato crops should consider strobilurin use carefully in the rest of the rotation, says Darryl Shailes (pictured), root crop technical manager for distributor”s HL Hutchinsons.

Continual use of strobilurins in almost every crop in the rotation might encourage resistance to build-up, he suggests.

That is particularly relevant where soil is the application target, such as for controlling take-all in second wheats. “Not using strobs in every crop might be a sensible precaution.

“Growers need to consider where their biggest cost-benefit from using strobilurins over the next 10 years is likely to be.”