3 July 1998

Tropical disease of wheat is found

WHEAT growers in Suffolk and Essex are being advised to use a higher cost seed treatment and drill late and shallow to halt the spread of a devastating new wind and seed-borne disease.

Warm countries

Flag smut, normally a disease of warm, dry countries, was discovered in a crop of Riband by Willmot Pertwee agronomist John Walker, of Earls Coln, Colchester. Black leaf striping, severely stunted plants and an absence of ears characterise the disease.

The crop was grown from guazatine (Panoctine) treated UK-grown C2 seed from a national supplier. Up to 400ha of Riband in Suffolk and Essex grown from related seed lots could also be at risk.

The Plant Health and Seeds Inspectorate is currently checking for symptoms in a sample of those crops. Quarantine measures are not ruled out.

Wind transmission could threaten adjacent crops, says Central Science Laboratory specialist Claire Sansford.

Unlike Karnal bunt, which has caused major export problems for affected US growers, flag smut is controllable, she adds. "Triademenol seed treatment, as in Baytan, plus late, shallow drilling should nail it. I dont believe we need quarantine areas," Dr Sansford says.

Restrictions

Brazil, Turkey, Canada and the US currently restrict cereal imports from countries with flag smut. EU countries do not.

This years outbreak is attributed to early drilling, the mild winter and dry conditions in early spring.