There are many factors that will make a wheat crop more likely to lodge — seeding rate, fertility, moisture levels, variety and so on, but when it comes to understanding lodging risk during the growing season, watch nighttime temperatures, says RealAgriculture agronomist Peter Johnson.
“At nighttime, what does wheat do? All it does is respire,” he explains. “Temperature drives respiration. For every 10 degree centigrade increase we get at night, respiration doubles.”
The more energy spent on respiration, the less photosynthate is available for the plant to develop a big, thick stem, notes Wheat Pete. Too many 20 degree nights and you’ll end up with a thin stem that’s far more prone to lodging, as was the case in parts of Western Canada in early July 2015.
“At growth stage 30, when we switch from vegetative to reproductive, start watching your nighttime temperatures then right up to flag leaf, and you can pretty much predict ‘do I need a growth regulator?’…or something else that I can do in terms of keeping that crop standing,” he explains. (Of course check with your buyer first before applying a growth regulator.)