Spring has arrived and as April roars in, it won’t be long before planters are cruising through fields.
It’s what happens, or doesn’t happen, after those planters are gone that will largely determine what kind of crop is ahead for farmers in the Midwest.
Without germination, a seed won’t grow, making it one of the more important aspects of crop development, and this year seed quality will likely depend on the region it came from, according to Iowa State University Extension crop specialist Mark Licht.
Drought stress, excess moisture or other pressure on seed growers may pull back on how well it will germinate in the upcoming year.
“We had some drier conditions, especially west of I-35, so any production in the western part of (Iowa) did probably have some drought stress with it,” he said. “That is probably going to pull back the seed size a little bit, but might not be as detrimental to the seed quality.”
He said a wet or cold fall with an early frost tends to affect seed germination the most, so while many producers dealt with drought conditions in the western part of Iowa, the seed crop should not see many issues overall.
Licht said farmers should be looking for 90-95% germination from their corn seed, and 95% germination from their soybean seeds is ideal, but expect closer to 90%.
“It just seems like soybean seed germination tends to be a little bit lower than corn,” he said. “We want to be in the 90-95% area with seed quality.”
Emerson Nafziger, professor with the University of Illinois Department of Crop Sciences, said modern planters do a good job of putting the seed into contact with soil without compacting the soil above, allowing for the greatest moisture availability. That will increase germination effectiveness, he said.
“Even soils with lower moisture content often have enough water to allow germination, especially in silt loam and silty clay loam soils without clods,” he said.
To get more out of the seed, Licht said planting into warmer and drier conditions is the best-case scenario, meaning holding off an extra day or two may be beneficial in certain cases. He said the seed tends to struggle emerging in cooler or wetter weather, in addition to picking up additional pathogens when germinating.
He suggested if a cold, wet weather pattern is coming in the next 24-36 hours to wait for planting if possible.
He also said to keep a close eye on emergence after planting to determine how well the seed germinated.
“If it takes five to seven days, you are probably going to have good emergence,” Licht said. “If it gets out to 14 to 21 days, your germination and emergence rates are probably lower than you might want, so you might want to check it out.”
Nafziger said the germination process can be very slow at low temperatures. Seeds will often “bide their time” until soils warm up. He said that seed in cooler soils, ranging around 40 degrees, may be subject to excess chilling, which can cause injury.
“That can mean abnormal growth and poor emergence even if seeds survive,” Nafziger said. “This is considered more of a problem in corn than in soybean, in part because more soybean seeds than corn seeds tend to die under such conditions and so don’t show those symptoms.”
For those who are considering a replant, he said the earlier a farmer makes that decision the better. The longer someone waits, the lower the yield potential is.
“If you get out into the June timeframe when you are making that assessment, all of a sudden, you might be able to stay with a lower plant population just because you’ve already lost yield potential because of later planting dates,” he said.