Two new sub-clover varieties

Known as Edison and Franklin, after eminent scientists, they have been bred to pick out the best features of the ‘old school’ parent plants.

Associate Professor Phillip Nichols, from the Annual Legume Breeding Australia (ALBA) team, said the newly launched subterranean clovers (known as sub-clover) hold great potential for summer dry climates. ALBA is a joint venture between the University of Western Australia and the world’s largest forage breeding company, DLF Seeds. DLF Seeds includes PGG Wrightson Seeds, AusWest and Stephen Pasture Seeds.

For those who know their sub-clover varieties, Edison is bred by crossing the dense and leafy Denmark which has good grazing tolerance but is slow growing in winter, with Woogenellup which is very winter active.

This gives Edison the advantage of producing bulk clover over winter. It is late-flowering so keeps producing longer through the spring season too, Nichols said.

“We crossed them together and got the best of both types in Edison.”

Nicols said it will have a strong fit with summer-dry areas in New Zealand. Edison was tested on the Canterbury Plains, as well as in Perth and eastern Australia.

“Edison will be a logical replacement for older varieties like Denmark, Leura and Mount Barker.”

“It is more productive and more persistent than all three and it may become your main sub-clover cultivar.”

The second new variety, Franklin, is a yanninicum subspecies annual clover, so can tolerate waterlogged areas over winter. Wetter soils that then dry out over summer, would be well suited, he said. It is a mid-season flowering clover.

ALBA is also currently evaluating more sub-clovers, particularly for medium and low rainfall areas, as well as new balansa, Persian and arrowleaf clover varieties.

“We are excited at the pipeline of new material coming through the program, with several new releases likely over the next few years.”

The delay between release and seed availability in NZ is that enough seed has to be grown in Australia for sale. Wayne Nichol, Technical Manager, PGG Wrightson Seeds, said this new seed supply relies on good production in Australia over the next two seasons.

“We have good availability of Bindoon, Coolamon and some of the older varieties though. Edison will be an improvement on Leura and early trials show great promise. My pick is that in our conditions, Edison will do well in yield advantage, especially on the shoulders of the season,” says Wayne.

Phillip Nichols said pasture legumes are important because they are a source of high-quality feed and can fix nitrogen from the atmosphere and put it back
into the soil for use by other plants in the pasture. This improves overall pasture productivity.

Sub clover is self-pollinated and bees are not involved in pollination. To create the cross, plant breeders had to physically remove the anthers (male part) from the flower before it sheds its pollen. It was then sprinkled (pollinated) with pollen from a selected plant variety.

“My pick is that in our conditions, Edison will do well in yield advantage, especially on the shoulders of the season.” – Wayne Nichol, Technical Manager, PGG Wrightson Seeds

The new varieties are not very hard seeded.

The Plant Variety Rights, as they are known in NZ, have expired for the older sub-clover varieties like Denmark and Luera. They then become known as common varieties. The new varieties will be a new earner for DFL companies.

Professor Derrick Moot, Lincoln University, said the management of annual clovers is key to getting the most out of them, no matter the variety. Information on annual clovers and how to introduce them can be found on the Lincoln University Dryland Legume website.

Reliance on South Australia for sub-clover seed

New Zealand relies primarily on South Australia for fresh sources of sub-clover seed, said Associate Professor Phillip Nichols, University of Western Australia.

The good news is though, once farmers have sub-clover established in pastures, careful management will keep a seed bank and enduring clover presence for years and years. This keeps the demand for shop-bought seed low. Once in the ground, sub clover is self-pollinating so the plants stay true to type. This means that existing varieties won’t breed the new one out.

To harvest the seed, the soil has to be dug up to be extracted, Nichols said. This is done in the dry of summer and done by raking off the top biomass and scarifying the soil. A vacuum harvester sucks up
the seed and soil and threshes the seed. A key issue for Australian seed growers is that their soil is left prone to wind erosion.

The age of infrastructure is another problem, with the youngest harvester machines now 34 years old. There is a project looking at more sustainable harvesting techniques and modernising the machinery, Nichols said.

Seed will be available from PGG Wrightson Seeds in 2026, and a third earlier-flowering variety should be available then too.