2 May 1997

Giving linseed a fair chance

FIVE knotgrass plants per square metre can cut the yield of spring linseed, according to a research project funded by the Home-Grown Cereals Authority.

Field trials were set up at six locations by the Arable Research Centres, IACR Rothamsted and Morley Research Centre. The aim was to determine levels of weed infestation which reduce linseed yield. Guidelines are that weed control pays if there are five knotgrass, six fat hen, 14 wild oat or 40 chickweed plants a square metre.

"Spring linseed is a useful break crop but it produces little biomass and so offers little competition to weed plants," says Dr Mike Carver, director of Arable Research Centres.

"The trials have established weed threshold levels which could cause financial loss if left untreated. However, the trials were conducted in three dry summers and it is possible that weed competition could be greater when moisture is less limiting."n