17 May 2002

NZ links find clovers to suit conditions in UK

LINKS with New Zealand plant breeders are also allowing evaluation of clovers, not included in the NI breeding programme, to find those suited to the UK.

One exciting forage variety was the NZ-bred Crusader, said David Johnston. He believed this variety would set a new standard for white clover: It has just been added to NIABs list. "It is off the scale for yield and persistency."

The link between NZ and NI breeders has also made it possible to ensure varieties with good seeding potential are developed. In the past there have been problems with good varieties for UK situations failing to grow well and produce enough seed to be economic when grown by NZ seed producers.

Crusader was one of 49 NZ-bred varieties tested in the UK. It is medium leaved and performed well in both a cutting and grazing situation, which was seldom found with a clover, he said.

There were already six farms with field scale crops of clover and perennial ryegrass and they were doing well, added Mr Johnston. Seed should be available in July. &#42

Rough guide to plant breeding

Grass breeding is similar to breeding pedigree cattle, says DARDs David Johnston. "As much care is taken selecting two plants as when a pedigree breeder selects cattle."

In a bag with pollen-free air pumped in, the two plants breed in May/June. But each seed has different genetics – as the progeny of cattle would – some will grow faster than others and they may have different disease resistance.

Then 10 plants cross pollinate in a tent to produce 1000 seeds for sowing in a plot. The best 100 plants are selected by eye – based on growth and appearance of rust or other diseases. Those not selected for breeding have their heads removed, said Mr Johnston.

Others are allowed to produce seed which is collected for further testing as a new variety. In addition, each of the 100 selected plants are split into tillers and planted in rows in a plot to investigate their potential. The best will be selected for testing in subsequent years.

DARD has about 4000 variety test plots at different stages of testing. From the first cross to marketing takes 14 years.