If weather permits, it's tempting to plant corn early. If that opportunity occurs, remember to choose the best planting date, prioritize fields, select stress-tolerant hybrids and consider seed treatment options, says an expert at Pioneer Hi-Bred, a DuPont business.
As farm sizes increase, more and more growers look to earlier planting to get all their acres done in time. Imad Saab, a Pioneer research scientist, says early-planted corn also may gain a head start on the flowering stage — potentially avoiding drought — as well as provide growers the chance to harvest and dry the crop sooner. Early planting carries an increased risk of stand loss due to the potential for damaging frosts and cold snaps in early spring, which can even require replanting.
"To help growers manage early-season risks like cold weather conditions or cooler, wetter soils from substantial residue, Pioneer provides stress emergence scores and high residue suitability scores for all hybrids offered in North America," Saab says. "Choosing hybrids with higher scores for these traits helps reduce genetic vulnerability to stress brought on by cold soils and high residue environments."
Pioneer scores each hybrid with a stress emergence rating, developed from years of testing in a wide array of stress environments.
"The company applies very extensive research from the field and lab to develop the hybrids growers are asking for," Saab says. "Our research locations include sandy fields that can be planted ultra early as well as no-till, corn-on-corn fields with heavy residue and very challenging seedbeds. This year we've added more field research locations to better serve our customers, and we're always chasing stressful conditions to push those hybrids to the limits and beyond with expanded field testing."
Hybrids assigned high stress emergence ratings show superior potential for stand establishment and uniformity under stress compared to other Pioneer brand hybrids. Besides extensive field testing, the company uses industry-leading lab tests and molecular breeding technologies to develop superior stress emergence hybrids.
"Pioneer breeders draw from highly efficient and predictive laboratory tests to evaluate tens of thousands of potential hybrids very early in the development stage," Saab says. "Using proprietary molecular marker technologies, breeders identify and select regions in the corn genome linked to superior, native genes."
Stress emergence scores of six to nine indicate above-average performance; five indicates average performance; and one to four indicates below-average performance to establish normal stands under stress conditions.
"I suggest growers diversify their portfolios and maintain realistic expectations," Saab says. "A strong stress emergence rating, say a seven, isn't completely foolproof. Corn is still sensitive to cold."
Finding the right planting date plays an important role for achieving optimal yields. Saab says the key to choosing an early planting date is finding the right combination of good field conditions, adequate soil temperature and moisture, and a warming trend in the forecast instead of just relying on a calendar date.
"Areas where the average soil temperature remained above 50 F for two weeks after planting typically have higher and more uniform stands than where soils were 50 F or below for the same period," he says. "Corn requires adequate moisture and several days of good weather after planting for successful emergence."
To protect against stand and yield loss, monitor soil temperature at planting depth and delay planting until soils reach 50 F. Well-drained, low-residue fields typically warm up faster and allow for more rapid emergence and seedling growth.
"Besides cold, compaction also can have negative effects on stand establishment. Seedlings emerging in compacted soils often exhibit symptoms like leafing underground, smaller roots and runts," Saab says. "If possible, refrain from planting until soils are sufficiently dry to minimize compaction, and make sure to use the right seed firmer and closing wheel to ensure good seed-to-soil contact and reduce compaction especially in no-till fields."
Consider seed treatment options when planting early. Early-season insects often are a problem in early planting and high residue conditions, and more so if seedlings are weakened by cold or overly wet soils.
"Insecticide seed treatments have proven to be very effective at protecting stands in stressful environments," Saab says. "Although these are insecticides, they also protect against seedling disease by reducing insect feeding and depriving pathogens of points of entry. These provide effective control of secondary insects such as wireworms, cutworms, seed corn maggots and white grubs. However, our research has shown that higher rates of insecticide seed treatments such as Poncho 1250 may be needed to maximize control of these insects under heavy infestations and especially in no-till fields. These insects tend to be active early in the season and can cause significant stand reductions, especially if emergence is slow due to stress."
For more information about early planting or to see stress emergence ratings for Pioneer hybrids in a particular area, talk with your Pioneer sales professional or visit the Pioneer website at http://www.pioneer.com and click "Seed Products & Traits by Region" under the "Product and Services" tab.