Corn Yield Projections Rosy Despite Growing Pains

August 22, 2003

COLUMBUS, Ohio — Flooded fields, reduced stands, seedling blights, poor root development, leaf defoliation, hail and wind damage — you name it, the corn crop has suffered through it. But despite the shaky growing season, early yield projections are rosy. According to the Ohio Agricultural Statistics Service, yield projections as of Aug. 1 are at 142 bushels per acre. If the number stays true, it would make it Ohio’s third-highest harvest in history — behind the 147 bushels per acre harvested in 2000 and 143 bushels per acre harvested in 1992. The yield projections are already 40 percent higher than last year’s paltry 88 bushels per acre harvested. “The projection is a bit of a surprise,” said Peter Thomison, an Ohio State University Extension agronomist. “With the soggy soils we’ve had for much of the year, we are very guarded about what to expect in these fields.” Thomison, an associate professor with the Department of Horticulture and Crop Science, said that early-season saturated soils played havoc with corn root development, resulting in shallow roots. Any late-season stresses on the crop, such as hot, dry weather or diseases, could still impact the crop, causing a drop in yields. “We are very concerned about root development. There are some fields where leaves are yellowing due to nitrogen deficiencies caused by excessive rains,” said Thomison. According to the Ohio Agricultural Statistics Service, the corn crop is five to seven days behind in development, mainly due to the cloudy, cool temperatures Ohio has been experiencing late in the growing season. “That could work for us or against us,” said Thomison. “Lower temperatures have helped prevent moisture stresses and limited foliar disease development, but the overcast, rainy weather has reduced photosynthesis.” Morever, the cooler temperatures are slowing corn development as the crop heads into the grain filling stage. The result could be lower yields. Also, cloudy, wet weather and cooler temperatures could also keep the corn from “drying down.” The longer the crop stays in the field, the greater the potential for stalk lodging and subsequent disease problems. “We could probably cruise to the finish line and end the season with decent yields in many fields. But the wild card is stalk quality,” said Thomison. “These hazy, cloudy conditions, rainfall and small root systems are a recipe for stalk quality problems. The plants will cannibalize the ear at the expense of the roots and lower stalks and that’s going to allow fungi to invade the plants.” Thomison said that stalk lodging and grain moisture level are two major issues facing corn growers as they wrap up the growing season.

Author(s): 
Candace Pollock
Source(s): 
Peter Thomison