Switching to winter beans can offer growers the chance to get on top of grassweed problems and spread workloads due to flexible drilling dates for the crop.
Some may be attracted to winter beans for the first time due to new CAP greening rules and the option of drilling the crop late into November.
Providing crops are well established and at the one- to two-node stage (two pairs of leaves) before the winter sets in, most winter bean varieties can be drilled right through October and November, reports Peter Smith of pulse specialist Wherry & Sons.
“The most recent variety introductions offer even more flexibility than this. With these, drilling can continue throughout December and into January and February, if need be,” he says.
“Of course, higher seed rates are required with later sowing dates,” Mr Smith adds.
In general, conditions at drilling are more important than sowing date. “Like all crops, beans need to get off to a good start,” he says.
As a result of their later sowing, successive flushes of blackgrass can be dealt with on land destined for beans, while other field work can be completed in optimal conditions.
“Winter beans offer much more than a break. Growers who are new to the crop, or are returning to it after a considerable time off, will find out that there are compelling reasons for making them a regular part of the rotation,” he says.
For optimum winter bean establishment, the seed should be drilled to a good depth. “This promotes good root growth over the winter and helps the crop to withstand any drought later in the year,” Mr Smith adds.
Minimum-tillage and direct-drilling systems are becoming more popular at the expense of ploughing beans in and are giving good results.
“The seed should be covered by a minimum of 6-7cm of soil, but it can be sown as deep as 15-20cm if it is ploughed in,” he says.
Seed rates should be increased from the traditional figure of 18 plants/sq m, as most varieties show a positive yield response to increased plant density.
“Our trials suggest the ideal plant population is 22-30 plants established, but there are recommendations more specific to individual varieties which we now have more confidence in,” Mr Smith says.
For Wizard, which is by far the most popular variety due to its very large seed size, there’s a target plant population of 24 plants/sq m. Honey, with its early maturity and shorter straw, has a target of 28 plants/sq m and newcomer Buzz has a target of 22 plants/sq m.
“Variety choice should be guided by your end market preference. Pale hilum types, such as Wizard and Honey, are suitable for the premium export market, while the black hilum types, such as Buzz, meet the needs of the animal feed market,” he adds.
Pre-emergence residual herbicides form the backbone of weed control programmes and work well where there’s soil moisture present.
“The later drilling date means conditions tend to be better for the residual herbicides,” Mr Smith says.
The current interest in winter beans and demand for seed is being driven by both agronomic and political factors, such as the new greening rules pertaining to ecological focus areas (EFAs).
“It’s not just about meeting the requirements of the three-crop rule and EFAs. For some time, the growing costs of other break crops have been rising, while the technical challenges of growing them have increased,” Mr Smith adds.
Oilseed rape is a good example of this. “Yields have been disappointing, prices have fallen and the neonicotinoid seed treatment ban has made crop establishment more risky,” he says.
“There’s also pressure on herbicide and slug pellet use in oilseed rape, due to our Water Framework Directive obligations, as well as a need to comply with nitrogen-vulnerable zones,” Mr Smith adds.
All of these factors combined have prompted growers to look for alternatives, with beans proving attractive to those with cereal rotations, he concludes.
Some winter bean varieties can be drilled as late as December and into January and February if need be.