By LON TONNESON
Germination tests can help you get the biggest bang for the buck from soybean seed. But which tests are best?
Adam Spelhaug, agronomist with Peterson Farms Seed, Harwood, N.D., says he looks at the warm germination, cold germination and accelerated aging tests.
The warm germination test is required and is printed on every seed tag. This test gives a good idea of stand establishment at ideal conditions. Four hundred seeds are germinated for seven days at 77 degrees F and then evaluated. However, the test really only tells how well the seed will do in planting conditions devoid of stress.
“Most companies label their soybeans at 90%. While the actual germination rate may be higher, 85% is the lowest allowable level for certification purposes,” Spelhaug says.
The cold germination test gives a good estimate of how the seed lot will perform in cold/wet conditions. Seeds are placed in moistened paper towel at about 50 degrees F for seven days. The seeds are then kept at 77 degrees F for four days, planted and then evaluated for germination.
The accelerated aging test may best identify seed’s actual vigor. Seeds are placed on a wire tray and set in a box, with water below the tray. The boxes are aged at a temperature of 105 degrees F and 95% relative humidity for 72 hours, increasing the seed moisture to around 30%. The seeds are then planted and evaluated for their germination percentage.
An accelerated aging test within 15% of warm germination is considered acceptable, Spelhaug says.
When picking up seed, also check the seed visually, Spelhaug recommends. Seed should be uniform in size and color with no apparent seed coat splits, wrinkles or discoloration.
“There are so many variables that are out of your control once your seed is in the ground — temperature, cold soils, too much rain, not enough rain. Protect your seed investment by doing everything you can to get the seed off to a good start by insisting on the highest possible seed quality. Then protect it even further by using a seed treatment,” Spelhaug says.
This article published in the February, 2012 edition of DAKOTA FARMER.
All rights reserved. Copyright Farm Progress Cos. 2012.