AUBURN, Ala.— Corn producers are making plans to plant corn in the coming spring. As droughty conditions persist, growers are looking for assistance in making decisions.
Alabama Cooperative Extension System professionals have a resource packed with tips and tricks for navigating all of the El Nino Southern Oscillation (ENSO) phases and conditions. Following a cool, wet spring in 2016, producers are expected to experience conditions on the other end of the spectrum.
Periodic warming and cooling of the eastern Pacific Ocean waters along the equator compared to average conditions cause atmospheric and oceanic fluctuations of pressure, winds, sea level and precipitation in the equatorial Pacific.
The oscillation in atmospheric and oceanic conditions known as ENSO includes both warm (El Nino) and cold (La Nina) phases, with neutral conditions occurring between these two extremes.
Corn Yields During La Nina
Corn yields during El Nino and La Nina vary greatly based on solar radiation and available moisture.
Dr. Brenda Ortiz, a precision agriculture specialist with the Alabama Cooperative Extension System, said nonirrigated corn yields are lower during La Nina years because of the excess heat associated with this phase during June as well as cloudy days in July.
“Below average rainfall and above average maximum temperatures during June affect both pollination and the grain-filling period, leading to substantially reduced corn yield,” Ortiz said. “On the other hand, if irrigation is available during La Nina phase years, high solar radiation, which favors photosynthesis, can enable growers to achieve the highest yields, especially if moisture is available during the tasseling and grain-filling periods.”
Corn Management Strategies
Conservation tillage is a recommended practice for crops grown in the Southeast, including corn. Corn yields under conservation tillage equal or even exceed yields from conventional tillage practices and provide ecosystem services for long-term
Warmer and drier conditions may present a challenge to dryland corn growers, especially because of their reliance on adequate rainfall. Warmer soils promote vigorous germination, aggressive growth and fewer seedling diseases andnematode problems. Dryland corn growers should consider delaying planting to capitalize on later rainfall to ensure higher yields.
“In drier, warmer conditions growers typically deal with increased populations of stinkbugs, mainly on crops grown within reduced tillage systems, planted into grassy winter crops or weeds,” Ortiz said.
Lesser cornstalk borers and chinch bugs can present many challenges to producers. Southern corn rootworms are problematic pests in corn regardless of climate conditions.
Producers should scout diligently. Consider terminating cover crops two to three weeks before planting. Plant early to reduce soil insect problems, and use higher rates of insecticide seed treatments on corn planted in high-risk fields.
Warm, dry spring conditions increase the risk of charcoal rot and outbreaks of southern rust. Root-knot nematodes may remain active for longer periods in late fall and winter. They are also likely to increase in numbers and become active sooner in the next growing season.
Growers can reduce the risk of charcoal rot by using no-till or strip till on early planted corn. Scout for southern rust outbreaks beginning at tasseling and treat as needed with a fungicide.During the fall or early winter, collect soil samples for a nematode assay, especially in fields previously cropped to corn or cotton with a history of root-knot nematode problems. Use nematicides on nonirrigated corn to ensure a more robust root system.
Learn more about Climate and Crops, Alabama Extension’s newest iBook, at http://www.aces.edu/climateandcrops.
Climate and Crops focuses on the Southeast’s five major row crops: corn, cotton, peanut, soybean and wheat. It features multiple interactive options, including 17 videos, 33 interactive graphics and hundreds of images related to problematic insects, diseases and weeds.
Climate and Crops is a comprehensive resource not only for farmers, crop consultants and Cooperative Extension.