With plenty of thick crops coming out of the winter, and the mildest February since 2002, there is the potential for weak stems, while frost heave will encourage root lodging.
“The big factor is that establishment of autumn-sown crops was pretty good,” says Dr Berry.
“That means a decent plant population. If we get a period of warm weather in early spring, that will increase lodging risk.”
He advises growers to assess crops on a field-by-field basis. “There is a huge variation – don’t assume the harsh winter has knocked back growth.”
Although soil mineral nitrogen levels are not particularly unusual this year, the cold December and January has delayed mineralisation.
“It’s difficult to predict when it will come,” says Dr Berry.
“If it’s later in the spring and you’ve applied some early N, this will put your crop at a slightly greater risk of lodging, although this isn’t reasonable grounds to alter your programme.”
Crops should be assessed at Growth Stages 30 and 31. At GS30, a GAI above 1 represents a higher than average lodging risk. A GAI above 1.5 is higher risk at GS31.
A Plant Growth Regulator (PGR) application at either GS30 or GS31 in moderate or high lodging risk situations will reduce crop height and, therefore, the risk of both root and stem lodging, he advises.
A split application over the two timings will bring better results.
“Canopy (prohexadione-calcium + mepiquat chloride), Meteor (chlormequat + imazaquin) and Moddus (trinexapac-ethyl) are more effective in cold conditions. Other than that, all products do a good job.”
Rooting may also be a problem for some crops, Dr Berry notes. “Frost heave may have reduced anchorage.
“It’s worth rolling crops to consolidate the soil and help roots take a better hold. But this must be done before stem extension starts (before GS31).”
- Guidance on growth stage identification can be found in a Farmers Weekly Academy.
- For more from Dr Berry on canopy management, click here
- For more on canopy management and identifying Growth Stages 30 and 31, see our Canopy Management in Cereals webpage.