CFAES Give Today
News Releases Archive (Prior to 2011)

College of Food, Agricultural, and Environmental Sciences


Diseases Pressuring Soybeans

June 11, 2004

COLUMBUS, Ohio — Some soybean plants in Ohio are succumbing to disease pressures from excessive moisture, but over 65 percent of the crop remains in good to excellent condition, according to the Ohio Agricultural Statistics Service.


Anne Dorrance, an Ohio State University Extension plant pathologist, said that some plants are experiencing stand loss as the result of root rot diseases, such as Phytophthora or Pythium. And as long as soils remain saturated, infection in plants may continue. As of the week of June 6, Ohio soils remain nearly 60 percent saturated.

"Despite seed treatments we've had standing water in some fields, some wet for as long as two weeks. In other fields, we've had heavy rains over a short period of time that have just saturated the soil," said Jim Beuerlein, an Ohio State Extension agronomist. "What we need is a week of nice warm weather and another week to finish planting the crop. The eastern part of the state is having the hardest time getting the crop planted because it's been wet all spring."

According to the Ohio Agricultural Statistics Service, 73 percent of the soybean crop has been planted, with 63 percent of the crop having emerged. Both numbers are slightly ahead of last year's averages.

"In terms of stands, a lot of growers are questioning whether or not they've got enough plants for yield," said Beuerlein. "A good gauge is if you end up with 70 percent of as many plants as you drop seed, you'll have a perfect stand. That is, assuming you are following the recommended seeding rate. Even if the number is only half of the number of seeds you drop, it's still good enough for maximum yields."

Beuerlein emphasized that on light-colored soils, holding on to about 120,000 plants per acre is ideal for good yields, while on dark-colored soils, 60,000 to 70,000 plants is the bare minimum. "Light soils usually don't produce as much vegetative growth as dark-colored. So on light-colored soils, you'll need more plants to get good yields."

Growers in northern Ohio can plant soybeans up to the first week in July, while the southern Ohio growers have until the second week in July. "Yield potential that late in the game can range anywhere from nothing to up to 25 or 30 bushels per acre," said Beuerlein. "One saving grace is that almost all beans are planted in narrow 7.5-inch rows, which tend to yield better than soybeans planted in 30-inch rows."

In replanting situations, growers should choose varieties with high levels of partial disease resistance combined with a seed treatment.


Candace Pollock
Jim Beuerlein