This was the advice of the Processors & Growers Research Organisation (PGRO), which said growers' options were limited to bentazone-based products such as Basagran and Troy 480, MCPB - including Bellmac Straight, Butoxone and Tropoto - and MCPB + MCPA (Impetus).
A PGRO representative explained: "Most of the varieties shown on product labels are no longer grown and when considering varietal tolerance it is advised that PGRO should be consulted regarding any variety not mentioned."
The newer vining pea varieties on the PGRO descriptive list are tolerant of these treatments as long as label instructions are followed.
Higher temperatures mean better weed control but potentially more crop effects and with the hormones this means increased epinasty, but the crop should recover. If daytime temperatures are above 21 degsC then applications in the evening should be considered to minimise crop damage.
PGRO work on crop safety is based on full-rate and double-rate applications so using reduced rates should lessen the chances of crop damage further.