29 March 1996

WHITE ONE AT HOME IN THE COLD

THE Aberystwyth bred white clover AberHerald has performed well in linked trials on 12 sites in 10 northern European countries.

This medium-leaved variety proved to be more productive and more winter hardy than varieties adapted to local conditions in countries like Iceland, Finland and Sweden. Several successive mild UK winters meant that the variety, bred from genetic material collected in Switzerland, had only been evaluated under artificial severe cold conditions. Now COST 814, the EU-funded collaborative look at white clover overwintering, has demonstrated its exceptional persistency.

At each site AberHerald was compared with the New Zealand variety Huia, which is still first choice white clover in many European countries, and varieties from the other nine countries, including locally adapted ones. Clovers were sown in combination with the same intermediate perennial ryegrass, and one locally chosen one. At Aberystwyth the choice was AberElan.

Data was collected from the coldest sites in the winter and spring of 1994/95. Average spring herbage yield from plots containing AberHerald was 4.5 times higher than from the Huia plots. Average annual yields were 2.7 times greater.

Provisional results from all the sites, which all experienced very severe winter weather over the last few months, indicate that AberHerald has outsurvived all other clovers. Surviving clover plants from all the sites are made available to breeders in each participating country. These are being checked for any changes in type. This has already shown that a second IGER-bred variety changed on a site in Finland. AberCrest, a small-leaved variety with exceptional winter hardiness, developed larger leaves when it was brought back to Wales.

Dr Rhodes says the experiment, which will run for four more years, will provide much information on the nature of clover winter survival and spring growth under different conditions.

"When I talk to farmers I find there is tremendous interest in clover, but bad experiences in the past mean there is reluctance to make more use of it. But the rising cost of bagged nitrogen should encourage more people to look at new, more persistent, higher yielding varieties like AberHerald and AberCrest."

Work is continuing at Aber-ystwyth on the compatibility of white clover and different grass varieties. This will soon provide farmers with seeds mixtures containing varieties that all express their productive potentials.

Dr Rhodes thinks that red clover could re-emerge as an important legume. Experiments being conducted at IGER by a Chilean researcher are expected to improve the persistence of red clover under grazing conditions.n

Ian Rhodes with clover survivors from all the study sites.