Promising new lines of disease-resistant and fast-growing kikuyu, with high yields of more than 20 tonnes a hectare per year, have been identified, with hopes they will be suitable for commercialisation by 2026/27.
Dairy Up's P1 project explores new management options for growing and utilising more kikuyu over the summer and increasing the productivity of kikuyu-based pastures used by NSW dairy farmers.
The P1c project is one of five focus areas.
It explores the genetic diversity of kikuyu at key dairy-producing locations, evaluates kikuyu lines selected for increased biomass production and tolerance to salinity and drought, and is a collaboration between researchers from Dairy UP, the University of Sydney, and Hattons Turf.
The three new lines and the check cultivar, Whittet, are growing in large strip trials on-farm at Bega, Nowra and Camden.
Project lead Professor Richard Trethowan, University of Sydney, said kikuyu provided high amounts of nutritious biomass for cattle in the warmer summer months.
"We originally had two in the Nowra region, but one farmer's weed control was poor, so we dropped one," Professor Trethowan said.
"The others look great.
"Bega and Nowra are important dairy areas, and the farmers volunteered.
"We hope to get another in the Hunter Valley soon."
The last kikuyu pasture cultivar released for grazing, Whittet, was developed more than 40 years ago, and current cultivars are limited in adaptation, nutritional quality and scope.
"The genetic diversity in the new materials is completely different to Whittet and other releases," Professor Trethowan said.
"This should reduce genetic vulnerability in the pasture system."
The new kikuyu lines identified for further screening are high in crude protein, water-soluble carbohydrates, and fibre.
Prof Trethowan said the rapid biomass production, disease resistance and generally improved nutritive value of the new candidate materials were promising findings from the research.
"We had not selected for nutritive value before," he said.
The next step
A DNA survey of kikuyu fields continues, and researchers expect to have an accurate estimate of on-farm genetic diversity within the next few months.
Researchers plan to extensively evaluate the three new lines, plus Whittet, at these key locations in 2024, including grazing pressure and assessment of nutritive value.
At the same time, these lines are being screened under inoculation for resistance to common diseases of kikuyu.
Based on these results, replicated strip trials of at least one genotype plus Whittet will be established in a broader range of farms in NSW under grazing pressure in 2025.
Prof Trethowan and his team hope to identify at least one superior line suitable for commercialisation, multiplication and dissemination by 2026/27.
