Crop Management Challenges Increase With Early Corn Planting

Pioneer provides tips for managing early-season stress

DES MOINES, Iowa.- The trend toward planting corn earlier continues to grow. The reasons include increasing farm size and the need to cover a large number of acres within a shorter window of time at the beginning of the season and avoiding potential late-season drought and pest problems at the end. According to scientists with Pioneer Hi-Bred, a DuPont business, this trend presents growers with several crop management challenges that can impact crop productivity significantly.

Select best planting date
“Selecting the best planting date is the most critical decision growers must make to enable a crop to have a successful start,” says Imad Saab, Ph.D., Pioneer research scientist. "Growers should pay close attention to weather forecasts and consider specific field conditions and characteristics before deciding on a planting date.

“Knowing the history of your fields - what planting dates have worked, the soil type and drainage characteristics - is very beneficial,” says Saab. “Growers should consider waiting for warmer conditions before planting fields that are not as well drained or those with a track record of early-season insect pressure or seedling blight.”

Saab cautions that growers may not pay enough attention to near-term forecasts. Growers who plant ahead of an inclement weather event, such as snow or heavy rain, are typically at a higher risk of losing stand to stress. “We often hear of growers who speed up planting just ahead of a snowstorm to get the crop in the ground,” says Saab. “There often are significant disadvantages to getting a crop in the ground just ahead of a cold spell. The corn crop typically needs several days of good weather after planting for successful crop emergence. In fact, growers tell us they usually have better stands if they shut down the planter at least a couple of days ahead of a cold event.”

Saab also cautions growers not to plant if soil temperature is below 50 degrees.

Plant well-drained, low-residue fields first
Fields that drain better also warm up faster, which is much more conducive to rapid emergence and seedling growth.

“Growers planting corn early should try to avoid fields with drainage issues,” says Saab. “Besides being typically colder, waterlogged fields can hurt stand establishment severely, since corn has very little tolerance to flooding. Fields with better drainage can be planted earlier and give crops a better chance of being successful.”

Select stress-tolerant hybrids
Research has shown that corn crops experiencing stress immediately after planting can suffer significant stand losses. Saab points out that choosing hybrids with good early-season stress tolerance is an effective way to help offset these losses. Saab says Pioneer puts all corn hybrids through rigorous stress tests in multiple sites across North America. “We plant our hybrids early in a range of stressful conditions including no-till and corn on corn,” Saab says. "We also test our hybrids in proprietary lab stress tests designed to simulate highly stressful conditions.

“We test for stress emergence, which is the genetic ability to emerge and establish stand under less than optimal conditions,” explains Saab. “We assign each hybrid a 1 to 9 stress emergence score which is listed in our product catalogs. Hybrids with a higher score are typically better suited for early planting or planting into colder or high-residue seedbeds.”

Saab says Pioneer is making genetic improvements continually in the ability to establish stands under stress.

“We’re using biotechnology and molecular breeding tools to identify genes associated with stress emergence,” Saab says. “We have made significant genetic improvements in this critical trail, and these tools will help accelerate genetic gain for early-season stress tolerance.”

Effective seed treatment
Seedling pathogens such as Pythium and Fusarium often are more problematic in early planting conditions if the seedlings are weakened by cold or waterlogging. Saab says to combat this, Pioneer offers Dynasty® fungicide (azoxystrobin) plus a seed-applied insecticide. This treatment also includes the standard Maxim® XL fungicide and a polymer that improves plantability and reduces dust-off. Pioneer research has shown this combination is the premier seed treatment for corn stand establishment in the industry.

“Insecticide seed treatments have proven to be very effective at protecting stands in stressful environments,” Saab said. “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, seed corn maggots and white grubs. However, our research has shown that higher rates of ISTs may be needed to maximize control of these insects under heavy infestations. These insects tend to be active early in the season and can cause significant stand reductions, especially if emergence is slow due to stress.”