Projecting yields | Current varieties can produce 300 to 350 bushels per acre with good weather and management
There’s a simple calculation for figuring out grain corn yield.
Multiply the number of ears by the number of rows on the cob by the number of kernels in each row, and divide by 90,000.
That’s the yield, said DuPont Pioneer senior agronomist Sandy Endicott. The secret to getting high yields is for farmers to know their corn as well as they know their kids.
Endicott spoke to about 120 farmers in Lethbridge March 14, the last of three corn planter clinics that DuPont Pioneer has sponsored in Western Canada in recent weeks.
Read Also
China’s grain imports have slumped big-time
China purchased just over 20 million tonnes of wheat, corn, barley and sorghum last year, that is well below the 60 million tonnes purchased in 2021-22.
Most growers in southern Alberta grow corn for silage, but the grain yield is a major factor in starch content and feed value, Pioneer seed representative Adrian Moens said after the clinic.
As well, interest in grain corn production is rising as growers look for higher profits and a ready market in the local feedlot industry.
Endicott said the number of harvestable ears and the number of kernels on each ear will determine about 85 percent of potential yield. The rest is determined by the weight of the kernels.
Hybrid selection, seed treatments, seed placement, seeding rate and planter maintenance are the key factors in starting a corn crop with top production potential.
Endicott said U.S. farmers have been able to improve yield by 1.8 bushels per acre per year, on average, over the last decade because of irrigation expansion and fertility management.
“Every corn hybrid out there that we sell, that our competition sells, has the ability to produce 300 to 350 bushels to the acre. The genetics are there. It’s been proven.”
However, climate and management determine whether those yields can be achieved and farmers control the latter.
Endicott quoted studies from Ohio State University that showed a nine percent reduction in corn yields in zero tillage when soil had been compacted. A 15 percent yield reduction was seen on conventionally tilled fields with the same level of compaction.
“This is a silent yield robber, in my mind,” she said.
Root development is crucial to plant development, stability and production, she added.
“What you see above ground, leaf tissue as far as height and width, you should see that much below the soil in roots.”
Seeding rates have been steadily increasing in the United States, said Endicott. The average is 31,000 seeds per acre, but that figure rises in the northern states, where rates are 32,000 to 36,000.
She recommended a narrower row spacing in northerly climates.
“We see on average a two percent improvement in yield with 20 inch rows over 30 inch rows across the entire U.S.,” she said.
“So if you’re thinking about buying a planter and have a choice between a 30 inch and a 20 inch planter, buy the 20 inch planter. I think it’s going to pay for itself very easily.”
Planting depth should be at least 1.5 inches so the plants can establish stable roots that will support growth to maturity. Uniform seed spacing is also critical.
“We want every one of those plants going down that row to look exactly alike. If they come up within 24 hours of each other, no big deal. But if they come up more than 48 hours of difference from one another, those late ones are not going to contribute to yield like you’d like them to.”
Endicott is also a proponent of using hybrid B.t. varieties to protect against European corn borer, which is slowly making its way north and has been found in southern Alberta fields.
Management practices should be aimed at reducing stress at the four critical stages of growth: germination and emergence; V3 to V5 (three to five visible leaf collars); V15 to VT (tasseling) and R1 to R2 (silking to blister).
Stress at the V3 to V5 will reduce the number of rows on the cob ,and stress at V15 to VT will reduce total kernel count.
