Problems with lodging wheat? Lots of factors come into play, but farmers have options to improve their wheat stands. Peter Johnson, the Canadian agronomist behind the “Wheat Pete’s Word” podcast, presented “Breaking the Fall” at the recent Soybean & Small Grains Congress.

“You lose one bushel per acre per day that the crop is lodged,” Johnson said.

Stem lodging or (most often the case) root lodging means that the plant has less nutrient uptake. That means slower growth and less use of photosynthesis.

“Purple color can also mean phosphorus shortage, but not in early spring,” Johnson said. “Nineteen times out of 20, it’s not true.”

He listed factors in lodging to include seeding date, rain, height, seed variety, wind, root spread, stem strength, seeding rate, photothermal weather, nitrogen rate and nitrogen timing.

Using a plant growth regulator may help, but Johnson said, “It’s a tool, but there are others. If you just do that, it can stress the crop.”

Farmers experiencing lodging and using only PGRs have reduced translocation, root damage, reduce photosynthesis, increased disease and pest risk, reduced combine efficiency and the greatest yield loss at anthesis (up to 80%).

Johnson reported that in testing from 2021 – 2023, applying excessive nitrogen increases risk of lodging. Wheat varieties 25R74, PRO81 and Adrainus proved more resistant to lodging on average than B654SRW.

He added, “Maybe we can manage better, so we don’t need growth regulator.”

For example, the environment matters. More moisture, plenty of sunlight and warm nights all help wheat resist lodging. Planting in lower areas can be protective, as can choosing areas with clay soil and selecting the right time.

“Heavy clay soil almost never lodges,” Johnson said. “Planting date matters. If you want a high yield, plant early.”

Controlling plant diseases also makes a difference. “If you get early disease and don’t control it, you get massive lodging,” he said. “Disease lodging matters. Wheat plants sense when they’re planted.”

Plant density per acre also affects whether the wheat experiences lodging. “Higher seeding rate means more lodging,” Johnson said.

Research shows that treated wheat seeds sown at the rate of 350 seeds/square meter experienced three times the lodging as those at the rate of 250 seeds/meter, for example.

Managing the seeding rate by zone can affect yield. “You get more lodging in lower, wetter areas,” Johnson said. “Oftentimes, that’s where you need growth regulators, unless you tile a lot.”

Using too much nitrogen can also negatively affect the crop. Johnson said that over-application can cause lodging, “but that means yield loss and most of us don’t want to do that.”

Dividing the nitrogen application can help the plants get what they need without going overboard.

He’s also found that using a PGR on “sensitive” varieties like Wilken hampers yield, but on varieties like Raven, it worked well to reduce lodging and not significantly affect root growth.

“Lodging is driven mainly by environmental factors and high grain yields. Variety resistance to lodging is five-star important. Plant early. Watch the nitrogen rate and make a timely PGR application and a split application of nitrogen. Think about your seeding rate and control leaf and stem disease,” he concluded.

CCE’s Northwest Dairy, Livestock & Field Crops Program hosts the Soybean & Small Grains Congress annually.

by Deborah Jeanne Sergeant