29 March 1996


Grass hybrids and super efficient nitrogen-fixing rhizobia for clover are just two of the research focuses at IGER Aberystwyth.

Robert Davies reports

MUCH more use should be made of Italian ryegrass/perennial ryegrass hybrids in medium-term leys, says IGER grass breeder Dai Hides.

He hopes many farmers will take a new look at hybrids when Germinal Holdings, which markets herbage varieties bred at Aberystwyth, start selling new mixtures of three or four hybrids, plus white clover.

"Too often hybrids are treated like Italian ryegrass and only used to provide early spring growth in short-term leys," says Mr Hides, grass breeding and herbage seed research group leader. "But the perennial ryegrass component can give four- or five-year persistency and high mid- and late-season yields."

The new mixtures will contain a range of varieties that flower at different times between May 1 and mid-June. Swards created using them should behave like Italian ryegrass in the early spring, providing early bite and silage. Later in the season there will be abundant, non-stemmy, vegetative growth without flowering.

"Hybrids have not been given the chance to show what they can do. Many farmers do not understand, or use, the benefits of blending the two types of ryegrass in a hybrid. We hope farm demonstrations after the launch of the new mixtures, which will not contain perennial ryegrass, will encourage farmers to reconsider their potential."

Mr Hides has high hopes for the new tetraploid hybrid AberLinnet, which he sees as the natural high yielding, high quality replacement for Augusta. The variety demonstrated excellent hardiness over the severe winter, when many Italian and perennial varieties were decimated. Half showed rapid early season growth.

It is already on the national list and is a contender to go on to the recommended list this year.

Aberystwyth-bred diploid intermediate heading perennial AberSilo has now joined AberElan on the NIAB list. This has a first harvest year yield 3% above the control variety, Fennema, and a second harvest advantage of 9%. With two-year test average yield 6% above Fennemas 14.35t/ha, AberSilo is now the highest yielding variety in its class.

&#8226 Genetically engineered bugs in root modules to kill beetles.

&#8226 Super efficient nitrogen-fixing rhizobia for clover seed.

&#8226 Photosynthesising rhizobia on legumes.

Clover growth (from left to right) with poor numbers of native rhizobium only; growth with good native rhizobium population; inoculated seed used; new super rhizobia strain that will be available in 1997.

The tropical legume sespania which forms rhizobium nodules on its stems is now used in research.

Dai Hides: "Too often hybrids are treated like Italian ryegrass and only used to provide early spring growth in short-term leys."