Project to reduce weed seeds post-harvest

A project to reduce grassweeds by exploring harvest weed seed control is being undertaken with help from a Suffolk farm.

Previous research and experience in Canada and Australia has shown that seed control units (SCU) mounted on combine harvesters render 98% of seed that passes through the harvester unviable.

This project aims to help farmers establish reasonable expectation of what proportion of grassweeds are left standing at harvest.Working with Will Smith from NIAB, four farmers have fitted SCUs to test whether the devices work in UK conditions.

BOFIN network

The Seed Circle project is being run by the British On-Farm Innovation Network (BOFIN) – a group of growers and scientists who carry out their own on-farm trials and share the results, seeking scientifically robust ways to improvefarm practice.

In Suffolk, Adam Driver noticed a build-up of blackgrass in the chaff lines behind his Claas Lexion 8800, running on a no-till 12/36m controlled-traffic farming system. His is also using the SCU to keep meadow brome in check.

Meanwhile in Warwickshire, Italian ryegrass is grassweed enemy number one for grower and Velcourt farm manager Ted Holmes, who has been trialling an SCU fitted to his New Holland CR9.90 combine.

NIAB has now developed a protocol for farmers to take their own pre-harvest representative sample so they don’t have to wait for a weed scientist to come to the farm during the busy harvest period. Samples are sent to NIAB for assessment.

“There are two critical monitoring periods,” explains Mr Smith.

“First, we want to know the population of viable seed standing at harvest, which involves taking representative samples just before the combine goes through. Then we monitor what emerges into the following crop once autumn cultivations and drilling are complete.”

For Italian ryegrass the figures were 62% in Warwickshire in winter barley and 87% for spring barley. Testing found that a lot of the rygrass seed in the spring barley was unviable – possibly due to hot, dry conditions.

For full details, visit bofin.org.uk