21 April 1995

Improved linseeds show potential in NIAB trials

WINTER linseeds, offering much earlier harvests and potentially higher yields than spring varieties, are showing distinct promise at the National Institute of Agricultural Botany, Cambridge.

Two French-bred varieties – Arctica from ISP Dalgety and Oliver from Semundo – have come through their second winter of national list testing well, says oilseeds specialist Simon Kightley. "It is a good news story."

Last year there was another application for national list testing of a further variety from ISP. NIAB is also screening spring type Bolas from agent John Turner.

A few plants were damaged by frost and snow in late March but overall the September-sown plots are "flourishing" and close to flowering. "Since autumn the winter linseed has been the greenest block on our trial ground."

Spring varieties drilled at the same time for comparison also look good after the relatively mild autumn and winter. But Mr Kightley stresses the official candidates for this autumns national listing have been selected from specific winter breeding programmes. "Farmers should be very wary of trying their hand with spring varieties sown in the autumn."

NIAB had its first look at winter types in 1992, when November sowings came through the winter unscathed. "We had some scorch on spring varieties sown at the same time." The first official trials came a year later.

"Our 93/94 plots confirmed the good survival of winter linseeds." Over-wintered spring types suffered more frost kill in February. The winter varieties flowered very early – "more or less as spring sown linseed was emerging" – and came to harvest at the end of July. Yield, at 2-2.5t/ha (16-20cwt/ acre), was "comparable" with normal spring crops, which in practice that year achieved only about 1t/ ha (8cwt/acre) because of drought. Mr Kightley puts the winter types performance down to better establishment and deeper rooting.

"In three winters we have seen crops ranging from the cotyledon stage to 4-6in in height surviving equally well."

Decisions on national listing will be made in December, probably too late to permit much commercial activity this year, says Mr Kightley. "There is still a lot of development work to be done," he adds. Some winter variety plants have shown a tendency to tiller. This could have implications for sowing rates.

"There is still more to be done to place the yield potential in relation to conventional linseed," he adds. The big question is whether winter linseed can offer the 30% bonus that winter rape has over spring rape. "We really dont know yet."

But there are already clear advantages besides the earlier harvest. There is more opportunity to prepare good seed-beds in the autumn, he maintains. "You can afford to wait. And in three autumns we have had no problems with flea beetle." &#42