Delta Farm Press Logo

Waiting for the right conditions critical in corn planting

Timing is key to successful corn crop.

Katie Pratt

February 21, 2023

4 Min Read
Corn Seedling
Planting corn early has potential benefits such as early pollination, the potential for good weather conditions during ear fill and an earlier harvest.Farm Press

This article also appears in the 2023 Mid-South Farm and Gin Show program. The farm and gin show takes place in Memphis at the Renasant Convention Center on February 24 and 25. Admission is free, but advance registration can be made at:

Getting the growing season started off on the right foot is a must for Midsouth corn growers. Two new studies from Bayer Crop Science say while it may be hard, waiting for the right weather conditions will help producers give their 2023 crop a solid foundation.

While many growers may be itching to get in the field, they need to make sure long-term weather conditions are right before they plant, according to a study conducted by Jay Mahaffey, science fellow at the Bayer Learning Center in Scott, Miss.

Planting corn early has potential benefits such as early pollination, the potential for good weather conditions during ear fill and an earlier harvest. But planting early can also cause problems if the weather is not right during or immediately following planting. Planting when cool, raining weather is in the forecast can lead to germination and establishment issues.

“Early planting is important, but growers should not rush and do it at the first sign of springtime,” Mahaffey said. “You should plant when the seven-to-10-day forecast is conducive for planting. Planting should not be a day but a condition.”

Related:Planter prep tips available in free guide

Planting date effect

In his 2021 study, Mahaffey determined the effect planting date has on corn. The study looked at planting early, planting when conditions were favorable and planting late. This resulted in planting dates of March 12, April 5 and May 10. Mahaffey evaluated the corn for emergence time, ear size and average yield across all three planting dates.

In the study, planting date had the greatest influence on yield. Corn planted on March 12 yielded 194 bushels per acre. Corn planted April 5 yielded 238 bushels per acre, and the May 10 planting date yielded 197 bushels per acre.

“The 44-bushel yield difference between the March 12 and April 5 planting dates would make significant impact on a producer’s bottom line, especially with tight margins,” he said. “With $6 corn, that increase translates into an extra $264 per acre.”

Soon after he planted the corn on March 12, the crop endured temperatures in the 30s and 10 days of rain. Warmer temperatures and drier conditions in April helped that corn progress faster, and as a result, corn planted on March 12 and April 5 were both harvested on Aug. 25. Corn planted on May 10 was harvested Sept. 8.

Mahaffey said the similar yields for the March and May planting dates provides further evidence for growers to wait until conditions are right before planting.

“While growers should plant as early as they can, this study shows that it is not an absolute disaster if they plant a little later,” he said. “Growers should make sure they have their equipment adjusted and ready to hit the ground once planting conditions are right for their area.”

Day of emergence

In another study, Mahaffey looked at the effect the day of emergence has on corn yield. Many factors including soil conditions, weather conditions and seed quality can cause emergence delays in corn, but little is known about the impact those delays may have on yield.

The study was performed on corn planted after cotton in Scott, Mississippi. The corn was planted 2.5 inches deep with a seeding rate of 36,000 plants per acre using commercial planting equipment.

In the study, corn began to emerge five days after planting. The study showed no reduction in ear weight if the corn emerged within five to eight days after planting. By harvest, 93.4% of plants in the study had a plant or ear, and the field yielded 230.9 bushels per acre.

“Corn plants do not have to emerge within 24 hours for maximum yield potential,” Mahaffey said. “If corn emerges within five to seven days after planting, there’s not much difference in ear size or grain weight.”

Ear size

Mahaffey only began to see a 20% reduction in ear size on the ninth day following planting.

“If growers have a large portion of their corn crop emerge on day nine or later, they may want to consider replanting,” he said.

He repeated the study in 2022. Preliminary results are very similar to the 2021 study.

“Corn began to emerge three days after planting, and there was only a slight decrease in ear size for corn that emerged seven to eight days after planting,” he said. “Growers need not to panic if it takes a few days for the plants to come up.”

This study coincides with another study Mahaffey conducted on planting depth. Some growers plant corn at a shallower depth to get corn to emerge quicker, but that comes with its own set of issues. Deeper planted corn has better rooting, stronger stands and a decrease in bird predation compared to shallow planted corn.

“Deeper planted corn, which is planted 2 inches or deeper, out yielded shallower planted corn in almost every case in that study,” he said.

Subscribe to receive top agriculture news
Be informed daily with these free e-newsletters

You May Also Like