Some seed corn can germinate and thrive in cold, wet spring soils. Some can’t. The challenge is to know which seed has a high enough germination rate to handle harsh weather conditions before you plant. That knowledge can then help you determine when you plant or, in extreme cases, whether you need to return the seed to your supplier.
Farmers who implement precision farming practices, are increasingly investing in annual seed testing, notes Tim Gutormson, seed services director for SGS North America, Brookings, S.D.
“Five years ago only a handful of farmers had us test seed for them; now, it’s in the hundreds,” Gutormson says.
He adds, “Vigor tests provide another piece of information that can help farmers rank planting order of seed lots to achieve a targeted plant population.”
SGS receives requests from corn growers for four types of seed tests: standard germination, cold germination, saturated cold germination and the pericarp damage test.
The tests range in cost between $16 and $35, and farmers typically invest $75 to $100 per lot in testing, Gutormson says.
He defines what each of the four tests entail.
The standard germination test, or warm test, is conducted under optimum conditions to see what the maximum germination level is for seed. This seed germ percentage is what usually is represented on the bags or containers of seed you purchase.
The cold test involves planting the seed under 1” of sand that has a 70% water holding capacity (field capacity). The idea is to simulate being planted in wet, 50-degree F soils. The seed is stressed in this manner for seven days and then moved into a chamber with a temperature of 75 degrees to determine its germination rate.
The saturated cold test is the most stressful cold vigor test SGS conducts, Gutormson says. The seed is placed in 1/8” of soil at 50 degrees F and is then saturated with water to represent 100% of a field’s water-holding capacity. This restricts the seed’s ability to take up oxygen/exchange gases and creates respiratory stress in addition to stress from the cold water uptake.
“The saturated cold test simulates severe conditions that farmers may face only 1 out of every 10 years,” Gutormson says.
The pericarp damage test involves the seed being soaked in a solution of water and a dye. The dye colors places where there are breaks and damage to the seed coat.
This test is particularly useful to farmers who want to use starter fertilizer in the seed furrow, notes Missy Bauer, Farm Journal associate field agronomist.
Bauer adds that farmers sometimes need to accept a corn hybrid with lower saturated cold and cold germination scores if the hybrid offers high yield potential for their area. “You may just need to plant those hybrids when the weather is more favorable, so they go into warmer soils and have the opportunity to perform up to their potential.” Listen here as Bauer shares some additional thoughts on the value of germination testing.
Missy Bauer, Farm Journal associate field agronomist, shares some thoughts on the value of germination testing.