Mildew strob guide confusion
Mildew strob guide confusion
CLAIMS that guidelines for using a new strobilurin fungicide against mildew are misleading have been firmly refuted by its maker.
But growers could still leave crops unprotected, warns a distributor.
Syngentas five star rating for mildew control from new strob fungicide Acanto (picoxystrobin) could tempt growers to omit a mildew-specific product, says David Ellerton of East Anglian distributor ProCam.
He says that at a recent meeting in Scotland, growers believed Acanto offered full control of all strains of mildew. That could lead to them relying on Acanto alone, leaving them vulnerable to strob-resistant mildew.
"It is very irresponsible of Syngenta to say Acanto has a five star rating for mildew control, in the absence of resistant strains. Growers believe five star control means five star. But it doesnt. Weve lost the resistance battle in wheat and winter barley is going the same way."
But Syngentas Beth Hall says: "Acantos inherent activity is five star in sensitive mildew situations, and the development of resistant mildew is progressing a lot more slowly in barley than in wheat, where we would expect no control."
Syngenta believes strobilurins will give good mildew control in barley for this season at least and possibly next year. "But our policy is to always mix with a mildew product as an anti-resistance strategy."
She also highlights the potential for Unix (cyprodinil) to bolster mildew control. "It offers more than just eyespot control in wheat, it also helps protect against mildew. And in barley it offers rhynchosporium and net blotch control too, to complement Acantos foliar disease control." *