23 August 2001
Blight tools at risk in EU review

By Charles Abel

SOME of the mainstays of potato growers blight control armoury are under threat in the EU pesticide review programme, according to a leading potato agronomist.

Trustan (oxadixyl) and tin could be phased out in the review, believes Agrovistas John Keer, or even dropped by the manufacturer if re-registration proves costly.

“Im not saying Trustan and tin are going to go this autumn, theyre not. But we want to be sure we have something in place in case they do go.”

Agrovista has been conducting trials for possible replacements, which were shown to growers at a recent open day at Saxham, near Bury St Edmunds.

Forty-eight programmes are under evaluation in 200 plots, and Dr Keer rates two newcomers and a further one due next year as more than suitable to fill the gap.

“Ranman and Electis are a quantum leap forward and EXP 10810A (fenomen) from Aventis looks set to further boost blight control.”

In Agrovista trials last year, Ranman (cyazofamid) topped the list for foliar blight control and has the added bonus of mid-season tuber blight control.

Meanwhile Electis (mancozeb + zoxium) is a very robust choice, says Dr Keer, and gives excellent foliar control and good tuber blight control.

However, finding a direct replacement for the systemic and phenylamide-resistant blight busting activity of Trustan may prove tricky, he says.