11 August 1995

No need to fear super blight

SO-CALLED "super-blight" should be no worry to potato growers, says a leading Dutch blight expert.

The fear is that blight can reproduce sexually to create over-wintering oospores. Those could infect crops earlier in the spring. Sexual reproduction could also lead to greater variation in the blight population. That could make the disease harder to control if it led to greater fungicide resistance, say some researchers.

But even if sexual reproduction has occurred, the repercussions have not been felt, reckons Huub Schepers of the PAGV research station, near Lelystad.

Earlier blight infections have prompted some suggestions that oospores are causing problems already. But Mr Schepers claims such outbreaks can be attributed to infection from dumps instead.

"Nobody has demonstrated earlier infection. If it was very, very wet between ridges the oospores could germinate. But even then they would still have to swim to the plant. Farmers need not fear super-blight," he says. &#42