Some new crop soybean seed being tested by the Nebraska Crop Improvement Association is falling below the normal germination rate. Although a few lots came in at or above 95% germination, results are averaging in the mid-80% range.

Growers are urged to check the germination rate for soybean seed and adjust planting rate and use of fungicide treatments accordingly.

In a typical year, soybean seed lots tested by NCIA range from 88% to 98% germination. This year, however, samples ranged from 43% to 98% germination. The minimum germination for certified soybean seed is 80%, as set by the Association of Official Seed Certifying Agencies (AOSCA). The Nebraska Department of Agriculture has set a minimum germination standard of 75% for soybeans.

In uncleaned samples submitted to NCIA, there were a lot of dead, moldy seeds this year. These were cleaned out before germination testing, similar to what would happen in commercial seed production.

Concerns over soybean seed quality problems are widespread across the entire soybean production area in the U.S. because of an unusually wet fall that delayed harvest in seed-producing areas of Iowa, Illinois and Indiana, the sources for much of Nebraska's seed.

Wet fall conditions contributed to the development of several seed diseases: Phomopsis seed decay and purple seed stain. In fall 2018, purple seed stain was reported at above-normal levels in Nebraska. (There are no known sources of resistance for purple seed stain.) NCIA testing has shown little or no reduction in germination in purple-stained seed in its tests this year.

Related:Getting a handle on late-season soybean diseases

What can you do?
If the germination rate for your seed is lower than normal, consider adding one or more fungicide seed treatments and increasing your seeding rate. Various seed treatment classes and active ingredients do not work equally well against all pathogens. It's important to understand which diseases may be problematic in your fields and select products or a diverse combination from multiple fungicide classes.

Efficacy ratings are provided for soybean seed treatments in the 2019 Guide for Weed, Disease, and Insect Management in Nebraska on page 255, including for Phomopsis seed decay. This efficacy table was developed by university plant pathologists from throughout the U.S. soybean production area. Tables on the subsequent pages (256-257) list products by fungicide class or mixed modes of action. You also can view soybean seed fungicide tables excerpted from the guide online.

A fungicide treatment won't improve germination of dying or dead seeds, but it can help protect seedlings under stress and help ensure a better stand. A fungicide application should be considered for soybean, especially when the seed germination rate is below normal, you're planting early into cold soils that may delay germination, or you're reducing your soybean seeding rate.

Related:Cut soybean populations without hurting yield

With lower germination rates, how much should the seeding rate be increased? If you're shooting for a 120,000-plant-per-acre stand, and the germination rate is 80% rather than the 90% you usually plant, increase the seeding rate by the relative difference — or 10% in this example.

A lot of things can kill your stand after emergence, and you don't want to shortchange potential yield early in the season.

Insecticide seed treatments are not warranted in response to expected low germination but may be warranted for early-planted soybean in areas where bean leaf beetle feeding might be expected.

Growers also may want to have seed they have stored on-farm over the winter tested again to determine whether storage conditions may have further affected seed quality. Seed molds can die in cool, dry conditions or increase in wet conditions.

Each spring, NCIA tests 500 seed samples for the Nebraska Department of Agriculture to see if germination falls within an allowable range of that stated on the seed label. (These tests include all crops plus bird seed, horticulture seed, etc., sold in the state.)

They also conduct germination tests for seed companies and for individual growers. In these recent tests, germination of fungicide-treated seed was slightly higher than non-treated seed.

This report comes from UNL CropWatch, which is solely responsible for the information provided and is wholly owned by the source. Informa Business Media and all its subsidiaries are not responsible for any of the content contained in this information asset.