Oilseed rape growers can now use a new propyzamide knowledge hub containing the latest information and advice ahead of the key season for applications.
Corteva Agriscience has launched a suite of resources, including a website and video explaining how to get the best out of products containing the active.
The materials, some of which are new while others are updated, also explain how to ensure stewardship best practice is adhered to.
Products containing propyzamide – namely Astrokerb and Kerb Flo 500 – can be applied to oilseed rape from 1 October until 31 January, providing the crop has at least three leaves.
But despite the relatively wide widow, central to Corteva’s advice to growers is to focus on using "the right rate, in the right conditions and at the right time".
Clare Stapley, Corteva’s OSR marketing manager, said: “This is to ensure growers get the best efficacy as well as making sure the product stays where we need it – in the field, controlling weeds.
“These new materials we have created go back to basics on what propyzamide is, how it works, how to apply it to achieve the best outcome, and practical advice on how to use it responsibly.”
Astrokerb and Kerb Flo 500 are key to controlling grassweeds, especially blackgrass and ryegrass in oilseed rape.
Their importance in the programme has grown in the past decade as they retain the ability to take out grass weeds, most notably graminicide-resistant blackgrass.
“Propyzamide works best when applied to cold, moist soils, but this must be balanced with the need to protect water,” Ms Stapley explained.
“Soils should be at 80% field capacity (1-2.5cm of moisture), soil temperature at 10 degrees centigrade and declining, and an appropriate rate should be selected.
“Only use the maximum rate of 840gai/ha for severe blackgrass situations. A rate of 750gai/ha or 500gai/ha are recommended for less-severe blackgrass or other grasses and broad-leaved weeds. Only use one product containing propyzamide per crop per year.”
The appropriate temperature range for applications often occurs on or after 5 November.
Corteva has advised growers to be ready but resist the temptation to apply outside of the ideal conditions.
Data demonstrating the correlation between application date, dose rate and blackgrass control reaffirms the importance of waiting for the optimum conditions.
