TRIALS CONFIRM BENEFIT OF HIGHER SEED RATES FOR WINTER BEANS
Plant density trials carried out by winter bean specialist Wherry & Sons have again confirmed the yield advantage from using higher seed rates on certain varieties.
Wizard (LHS) at higher density on later sown plots, Clipper (RHS) for comparison
In a repeat performance of 2 years ago, crops drilled at the equivalent rate of 36 plants/m² gave the highest yields across most of the winter bean varieties tested.
“Like other crops, winter bean yields were particularly good this year,” comments Peter Smith of Wherry & Sons. “Many crops came in at the 7-8t/ha level, after a good growing season with plenty of moisture and sunshine.
“And in a mirror performance of our trials, generally those that did the best of all were sown at higher seed rates.”
The trials, which were sown in mid-November, looked at three different plant densities, he reports.
“We plant them at differing distances apart in the row,” he explains. “In this trial, the rows were 30cm in width, while the three densities were 18cm, 12cm and 8.5cm.”
These densities are equivalent to 16 plants/m², 24 plants/m² and 36 plants/m² respectively, adds Mr Smith.
Yields of Wizard, Sultan and Honey showed stepped improvement as the density increased and were highest at the greater density, whilst yields of Arthur and Buzz were optimum at a level in between the medium to highest densities “We’ve been aware for some time now that all varieties respond to higher plant populations than the standard 18 plants/m²,” he says. “These trials are further proof of that and confirm that even in very different growing seasons, there’s an advantage from using a higher seed rate to suit your variety choice.”
The shorter, stiffer varieties such as Honey that don’t branch as much are most suited to this approach, he advises. “Our experience with Wizard, which is the most popular variety, is that growers should aim for around 24-28 plants/m², however this will vary in individual situations.”
Mr Smith advises that mid-October onwards is the best time to drill winter beans. “It’s a mistake to go too early, especially while it remains warm.
“You want to get root growth developing underground before the winter, but not leafy growth. That makes the crop susceptible to cold winds and damage.”
Extracted from FWI article, Autumn 2014