Maintaining seed quality has been a subject of study in the Farm Journal Test Plots for many years. Through our program, the plot crew has learned how to handle seed in order to maximize its potential.
"To understand how to preserve seed quality, we've tested seed sizes and planter meters," says Farm Journal Field Agronomist Ken Ferrie. "Some seed sizes are more prone to damage. In a round seed, the germ area is not as well protected as it is on a flat seed. This makes round seeds more susceptible to damage from handling."
Ferrie emphasizes the importance of seed quality in achieving successful planting and even emergence.
"We hadn't looked into whether bulk-fill planters and air delivery could have any effect on quality, which is something farmers have asked me many times," he explains.
To test bulk-fill planters and their air delivery systems, Ferrie designed a protocol to use across a group of central-fill planters currently on the market. The 16-row planters used were: Case IH Early Riser 1250, Great Plains Yield-Pro 4025, John Deere 1770NT and Kinze 3660 Twin-Line.
"With the different planter styles, gravity-fed individual row hoppers and air delivery from bulk-fill hoppers provide a different ride for the seed from the bag to the field," Ferrie says. "We wanted our test to measure if bulk-fill planters and their pneumatic systems pose any threat to seed quality."
Three of the planters tested used vacuum seed metering systems, and one was a finger pickup system.
The test team ran the protocol two times for each planter with two seed sizes—a medium round and a medium flat seed. The planters were tested with the same lot of seed, although the testing dates spanned up to a month.
Here's a step-by-step description of how the protocol was executed for each of the planters tested. These steps were repeated for each seed size.
Stage 1 For each planter test, the test team started with one seed size and coated it with a seed lubricant (graphite or talc, depending on the recommendation).
Stage 2 A pre-test seed sample was taken to know the initial seed quality before starting each test.
Stage 3 The test team placed a tarp across the planter's hopper, and the seed was loaded onto the tarp and lowered into the bulk-fill hopper.
"We were sure to handle the seed in a uniform manner so we didn't cause any additional damage," Ferrie says. "Dropping the seed into an empty poly hopper could damage the seed."
Stage 4 The crew took samples at the two closest rows and two farthest rows on one side of the planter. With the hoses disconnected from the meters, the planter was engaged to distribute the seed, and it was collected in a sock.
"The sample was collected before metering to try to narrow down when damage may occur," Ferrie says. "We collected seed at two different positions on the toolbar to see if the distance traveled affected quality."
The crew used socks to catch the samples because of the soft material and because they lessened the risk of the crew causing unfair damage.
"Seed-on-seed contact doesn't cause damage," Ferrie says. "It's when seed clashes with a harder surface that can cause cracking."
Stage 5 The plot crew combined the samples from the nearest rows into a test bag and then combined the samples from the farthest rows into
another test bag.
Stage 6 Next, the hose was reconnected to the meter, and the crew moved to the end of the seed tube and collected another set of seed samples after running them through the meter. The planter was engaged, and the samples were again caught in socks.
"It was important to collect samples before and after metering, as metering systems handle seed differently," Ferrie says. "We ran the seed through different metering systems to see how they could affect seed quality."
Stage 7 The plot crew combined post-metering samples from the closest rows into a test bag, and then combined the farthest samples into another test bag for analysis. The planter was thoroughly emptied out of the first seed size. Then the plot crew reloaded the planter with the second seed size, and the entire test protocol was repeated.
Results The samples were sent to an independent seed lab. The results included measurements for pericarp damage, or cracks in the seed coat.
"We used industry-standard sample sizes and quality tests," Ferrie says.
In analyzing the results, the plot crew used the presample measurements to set the baseline seed quality for each seed size in each planter test.
"One of the first factors that affects a planted seed is water. If cold water below 50°F can leach through cracks in the seed coat, it can cause seed chilling, disorient the seed and cause the mesocotyl to corkscrew in the ground,"
Ferrie explains. "This makes the seeds more susceptible to seedling blight, and it also leads to uneven emergence and stand failure."
The results show that the bulk-fill planters in these tests caused no significant measurable damage to the seed. Further, there was no measurable difference among planter models.
"Statistically, there was no difference in our results, which backs up what I have observed out in farmers' fields," Ferrie reports.
Compared with the pre-test samples, the medium round and medium flat seeds sustained no more than 1% severe and medium pericarp damage. Also, there was no difference in the quality of seed based on where the samples were taken—before metering or after metering.
"The farmer can damage the seed more by improperly handling it than the planter," Ferrie says. "My biggest concern during these tests was the round seed, but it maintained its quality very well."
Ferrie says the results solidify in his mind how well bulk-fill planters handle seed and maintain overall quality.
"When it comes to today's corn seed and commodity prices, having this data makes me confident bulk-fill planters on the market don't cause additional seed damage," Ferrie says.