Soybean production has sure changed in the past 20 years! Some of you will recall filling your drills with a pail – now we're able to use belted conveyor tenders to gently move it. Remember the "controlled spill" planting method with the old grain drills? Now we have planters with precision accuracy. Equipment technology has allowed better yields with lower seeding rates at planting. But to get the highest germination – and the best bang for your seed buck - you still need the highest quality seed.
But how do you know what you're getting? Be sure to check the seed visually as it is loaded into your tender or truck. Seed should be uniform in size and color with no apparent seed coat splits, wrinkles or discoloration. But more importantly, how do you know the physical and internal quality of the seed? I suggest asking your seed dealer what quality tests have been performed on the seed lot.
Warm germination test
The warm germination test is required – and is what is printed on every seed tag. This test gives a good idea of stand establishment at ideal conditions. 400 seeds are germinated for seven days at 77 degrees F and then evaluated. It really only tells how well the seed will do in planting conditions devoid of stress. Most companies label their soybeans at 90 percent. While the actual germination rate may be higher, 85 percent is the lowest allowable level for certification purposes.
The cold germination test gives a good estimate how the seed lot will perform in cold/wet conditions – something we are quite familiar with in the northern plains. The seeds are placed in moistened paper towel at about 50 degrees F for seven days. The seeds are then transferred to 77 degrees F for four days, planted and then evaluated for germination.
Accelerated aging test
An accelerated aging test is another indicator of a seed's performance. It is the best method to identify the 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 within 15% of warm germination is considered acceptable.
Some seed dealers may not know much more than what is printed on the label. But information should be available from the seed supplier upon request.
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 is an agronomist with Peterson Farms Seed, Harwood, N.D. For more information, contact him at 866-481-7333 or [email protected]