A simple test developed in the 1960s has been revived to help lucerne growers identify the extent of seed damage during harvest, so they can immediately adjust header operations.
The test was uncovered in a review of existing lucerne research by South Australia’s James De Barro, who led the five-year project Understanding and managing the causes of abnormal seedlings in lucerne for the RIRDC Pasture Seeds Program.
James, a former lucerne seed grower, said the test simply involved taking 100 seeds from the header bin during harvesting and soaking them in a ferric chloride solution. Any damaged seeds would turn black within 15 minutes.
The test identifies even hairline fractures in seed casings that indicate damage to the seed embryo, which can result in critical plant deformities such as broken leaves, or missing leaves and root systems. Protecting the viability of the seed is crucial, he said.
Take care during harvest
James’ research found that harvesting practices were the main cause of seed damage. Spraying, fertilisers, plant genetics, windrowing and weather damage were all discounted as significantly contributing to the problem.
According to James, buyers usually discount seed when the damage rate exceeds 15%, sometimes cutting prices offered by as much as half.
“Some buyers have already reduced the rate of damaged seed they will accept from 15 to 10% before applying discounts,” he said.
“The lucerne seed industry has become much more competitive in recent years, so harvest damage is an issue growers need to keep on top of.”
“Fortunately, the RIRDC project has made it relatively easy to identify when it is a problem so growers can do something about it.”
Lucerne seed damage test kits are available, through Alpha Group Consulting, in Keith, South Australia.
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