Oilseed rape variety lodging scores were coming under scrutiny at Cereals 2012, following numerous reports of crops going down in wet and windy conditions.

Serious lodging pressure is causing difficulty for growers for the first time in quite a few years, acknowledged Simon Kightley of NIAB TAG, who pointed out that little or no lodging in previous years may have led to some complacency.

“It could be that a seven rating for lodging is indicative of risk in a wet season,” he commented. “We need to get through this season and take another look at how varieties have performed compared to their rating.

“It’s not a disaster, by any means, but there indications of straw weakness. I expect we will see better differentiation between varieties in the future.”

Essex independent agronomist Jamie McKay agreed. “What we’re seeing in the field is that you need to go for a variety with an eight for lodging in years like this one.

“Varieties which did very well last year are wobbling this year.”

Hybrids have been affected more than conventionals, commented AICC member Peter Taylor. “They tend to be taller so are more at risk of being blown over. It’s really important to follow breeder advice on seed rates with hybrids – if you’ve drilled too much seed you will have a crop with thinner stems.”

But Philip Marr of Agrii suggested that root lodging was the problem, rather than stem lodging, making a variety’s rating almost irrelevant to this year’s situation. “The rating on the Recommended List is a stem lodging score, which isn’t what we’re seeing in the field.”

He stressed the importance of good root structure, especially with an early variety. “These types are fast developing and produce a big biomass going in to the winter, so without good root adhesion they will be blown about.

“We’ve had wind and rain at the wrong time for them. It doesn’t help that crops are the tallest that they’ve ever been.”

Richard Elsdon of United Oilseeds believed that the lodging problem was localised, rather than varietal.

“It seems to have been caused by plants revolving in the wind, together with poor root anchorage in wet soils. The combination has proved too much for some crops.”

He advised growers to re-examine their spring agronomy and hold off with nitrogen. “Later nitrogen applications in the spring will result in a shorter crop. There shouldn’t be any nitrogen applied at all until the crop is six inches tall.”

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