Germination Issues Affecting Soybean Seed

There's high demand and low supply of quality soybean seed for 2008 planting.

Midwest farmers who want to plant soybeans this spring but haven't lined up their seed supply yet are finding they aren't able to get their first choice and sometimes not their second choice in terms of varieties they want to plant.

There is an increased demand for soybean seed along with a decrease in availability of high-quality soybean seed for 2008 planting. Many seed companies are dealing with poor germination and increased seedling diseases showing up in seed tests this winter, because of poor harvest conditions this past fall.

"Low germination is going to be an issue in some areas, but that's not uncommon given the weather conditions we saw in the fall," says Palle Pedersen, Iowa State University Extension soybean agronomist.

Seed quality problems in seed this winter

"The 2007 crop year was challenging in many areas of the Midwest," says Tim Gutormson, North American manager for seed testing at SGS/Midwest Seed Services at Brookings, S.D. "Much of the southern soybean-producing region experienced severe drought, followed by extremely high temperatures during seed fill. This created low-moisture beans, which are more prone to mechanical handling damage, which can result in abnormal seedlings when germinated."

Other regions of the Soybean Belt had good growing weather but experienced a rapid maturation and dry down followed by a wet harvest season, he adds. This delayed harvest, as well as increased field weathering and exposure to fungi.

"Soybeans never improve in quality from the time of ideal harvest moisture," says Gutormson. "Weathering of soybeans leads to declining physiological integrity, as well as increased chances for fungal infection, seed staining, cracked seed coats and diseases such as Phomopsis seed rot and decay. Phomopsis may reduce seed quality, vigor and viability. Planting diseased, poor-quality beans will result in reduced stands that may reduce yields."

Low-germination beans may reduce yield

Around 16% of Mid-West Seed Services' standard germination tests on seed beans produced in 2007 shows Phomopsis infection. Gutormson says seed companies have discarded the bad lots and are currently cleaning and retesting the good lots. With that said, germination tests from his company show there is a shortage of high-germ seed available.

The significant decline in the number of seed lots germinating above 90% makes careful handling and seed treatments even more important.

Adjust your seeding rates this spring

"Fortunately, most of our soybean production fields weren't affected by the late fall rains and didn't have to sit in the field for long periods before being harvested," says Don Latham of Latham Seed Company in Alexander, Iowa. "Latham Seeds has excellent germination on most of our soybean brands."

Most seed companies prefer to sell soybean seed that has at least 90% germination, says Gutormson, with 80% to 85% considered as the lowest quality the seed companies want to market when seed supplies are tight. "If your seed has poor germination, you will need to increase your seeding rate. That will cost you a bit more," adds ISU's Pedersen.

To determine your seeding rate, Pedersen says you need to first determine your desired stand at harvest. If your germination is only 80% but you normally buy seeds with 90% germination, then you know that you need to increase your seeding rate by 10% or higher to get your desired stand.

"With soybean prices at record high levels, the last thing you want to do is risk yield by planting poor-quality seed," adds Latham. "Premium quality is more important than ever." Latham Seed Company is a leading independent, regional company that provides soybean seed to thousands of farmers across the upper Midwest states of Iowa, Minnesota, Wisconsin, Michigan, Nebraska, Illinois and South Dakota. Founded in 1947 by Willard Latham, the family firm focuses on soybean research, development, production and marketing.

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