When you purchase your rye-grass seed do you choose a branded product or a variety? Do you even know the difference? If not you are not alone. Most people assume that the label on the bag is specific to a genetically distinct plant. However, this is not necessarily the case. Western Dairy, with the help of local seed retailers, have established the WA Seed Productivity (WASP) trials to unravel the fact from fiction about the productivity of Western Australian rye-grass pastures.
Achieving high production and consistency over multiple seasons is somewhat complicated because there are two types of rye-grass available on the market; variety and brand. A variety is a generic rye-grass with distinguishing characteristics that are retained when reproduced. A variety has the capacity to deliver consistent production across multiple generations.
On the other hand branded seeds may vary genetically and potentially be inconsistent in production across multiple generations. Branded seeds are bred from varieties that express desirable phenotypes (the interaction between the environment and plant genotype). The term “brand name” is a distinguishing trademark for the seed but is quite often used interchangeably with “brand”, and this confuses the issue because rye-grass “varieties” and “brands” have a brand name. This means that when purchasing seed it is difficult to know whether it is a variety or a brand.
Irrespective of the brand versus variety issue, WA farmers need to be informed of the likely performance and profitability of rye-grass seed available for purchase. Pasture is the most important source of feed for Australian livestock farmers with over $100 million dollars spent each year on pasture renovation. Western Dairy sought to determine the relative milk profit potential (MPP $/ha) of a representative selection of annual rye-grass brands and varieties sold in WA. It was likely that branded rye-grasses would outperform variety rye-grasses because desirable production traits have been selected by seed companies from the rye-grass varieties.
The WASP trials, were developed by Western Dairy to provide farmers with the power to select the best rye-grass for their system. Six tetraploid annual rye-grasses (two Brands and four Varieties) were selected to determine the productive performance in a targeted region with no fertility constraints. A rye-grass was selected from each of the major seed distributors in WA and established in plots in May 2017 using the Meat and Livestock Australia protocols for pasture trials. The rye-grass was harvested at the 2 to 2.5 leaf stage throughout the growing season and measured for cumulative dry matter yields and quality.
The trial site was provided on a dairy support block at “Carenda Holsteins”, owned by the Kitchen family at Boyanup that was characterized by sandy soils over clay.
Relative Milk Profit Potential (MPP $/ha) was calculated as a value relative to the lowest rye-grass performer of the trial using the formula: Extra milk yield (L) x estimated milk price (cents per L) — (the seed cost (the seed cost of lowest rye-grass performer)).
Extra milk yield was defined as the energy yield of the pasture less the energy yield of the lowest performing rye-grass) x Litres of milk per MJ of ME and a pasture utilization of 75 per cent. Contact firstname.lastname@example.org for details.
Rye-grass Brand 1 showed significantly higher MPP $/ha than Varieties 3 and 4 which supports our expectation (Table 1). However, the results should be considered in context of the trial conditions. A dry autumn resulted in a very slow establishment and the first harvest was subsequently late (August 22). A warm weather event in November on the poor quality soils of the support block desiccated the plants, and the final harvest one week later was small with mostly dead plants. These conditions may have interfered with the expression of the genetic potential.
So what is the best rye-grass for WA farmers? The outcomes from this work raise some important issues. A rye-grass Brand may or may not yield higher in certain conditions and may vary over multiple seasons. A Variety is genetically more stable and reliable but does it yield as high in the short term?
What is clear is that repetition of these trials over multiple seasons and at multiple sites is crucial and will strengthen the confidence in the data that is generated.
There are three main messages to farmers that are emerging from the WASP trials; be informed using the information that is disseminated by Western Dairy; know your system including soil type and fertility and feed demand fluctuations; and ask questions when buying seed including the reliability of research that was done to generate seed recommendations.
• Peter Hutton is a research scientist with Western Dairy.