CROP UPDATE NO 11 - WINTER BEANS – AUTUMN AND SPRING SOWN - 6TH NOVEMBER 2019

With the autumn conditions delaying sowing of many crops growers are asking questions about how late winter beans can be sown, bringing back recollections of the winter of 2012 /2013.

Trials conducted at PGRO back then showed that winter beans sown in the spring were not a disaster, even at 18 plants/m². Maturity is, however, later by the order of 7-12 for days for Wizard.

Now as back then growers having seed in the barn (either bought or saved) are asking the inevitable questions:

- How late can I plant winter beans?
- Can I plant winter beans in the spring?
- What is the likely yield?
- And how late will they be to harvest?

In 2012 a small amount of previous trials, indicated that they could be grown when planted in the spring, but to treat them as a spring bean, increasing the plant population to more like that of spring beans (typically 40 plants/m²).

Of course, PGRO winter bean trials 2012/13 suffered the same fate as commercial plantings and this gave an opportunity to gather some concrete data.

As part of the Optibean project, winter beans Wizard and Clipper were sown at 3 sites, at 4 populations and and at 3 sowing dates. A summary of data is presented here from the sites at Dowsby, Lincoln and Thorney.

Main conclusions

• On average winter beans Wizard and Clipper sown in the spring at 18 plants/m² gave a 34% yield reduction compared to autumn sowings at the same population. 

• This yield reduction was lowered to 18% on average by planting 36 plants /m² in the spring compared to 18 plants/m² in the autumn. 

• Spring sown winter beans at 36 plants/m² did not match the yield of spring sown Fuego.  With Wizard and Clipper yielding 83% and 90% of Fuego respectively. 

• Autumn sown Wizard and Clipper at 18 plants/m² yielded as well as, or a little better than Spring sown Fuego.

• End February sown Wizard matured 12 days later than mid-October drilled Wizard and 7 days later than late-October drilled Wizard.

• End February sown Wizard matured 8 days later than early March sown Fuego.

To stress that winter beans sown in the spring were not a disaster, even at 18 plants/m².  Maturity is however, later by the order of 7-12 for days for Wizard.   

It must be remembered that 2013 was a late season for most crops, by about 10-14 days.  The lateness of the season benefited autumn crops sown in the spring and, indeed, late sown spring crops too. 

(Edition Number 11 : CB1911)