Dry pulse seed needs extra care

How to minimize losses from dry and damaged pulse seed this seeding season

Seed coat damage has occurred in this photo. After the seed was soaked for two minutes in room temperature water, the seed coat is coming off, or is in the process of coming off.

In the fall of 2017, pea and soybean pedigreed seed came off the field on the drier side, which means that they’ll be going into the field drier this year. Manitoba pulse crop specialist Dennis Lange shares his expertise on how to make sure dry, damaged seed doesn’t impact your bottom line.

Generally, seed quality is determined by the fall of the previous year’s harvest. Last year, conditions were dry during field pea harvest, and while peas came off in really good quality, they were also very dry, said Lange.

When seed lots — particularly pedigreed seed — gets down to 10 to 11 per cent moisture, producers have to be very careful during handling, warned Lange. Growers producing seed, he said, should ideally harvest at around 16 per cent moisture.

With harvest done and seed ready for planting, growers need to ask questions about the seed lots they’re purchasing. When seed coats are damaged — and damage can be as little as a hairline crack — germination and crop emergence can be impacted. No producer wants the added challenge of poor stand establishment.

Poor emergence and stand establishment is a bigger issue in peas than in soybeans.

“What happens is that those plants are so far apart that sometimes it’s difficult for these tendrils to reach each other and interlock,” explained Lange. “If you have that kind of stand — that seven to eight plants per square foot — the plants interlock and it keeps them standing better.”

Sparser stands tend to have more weed control issues, too, he added.

In soybean, stand establishment is less of an issue, as they branch out a lot.

Know your seed

Sometimes it’s difficult to know what you’re buying, though. Lange suggests that growers ask seed dealers about moisture levels. While germination tests are recommended, unfortunately, they don’t always provide answers, said Lange. “Germination will give you a good idea, but if it’s a dry seed lot sometimes those cracked seed coats don’t show up as dramatically in the germ,” Lange said. “The plant will germinate, but it doesn’t produce a healthy plant.”

Instead, Lange recommends a cracked seed coat test, which works for both field peas and soybeans. To do this, put about 100 seeds into a small container of water — about one inch deep — and let them soak for about five minutes. Stir the seeds around to see if any of the coats have peeled off. Count the number of cracked seeds.

“If you’re upwards of 15 to 20 per cent that means that you might need to increase your seeding rate by a certain amount to compensate for those plant stands,” Lange said.

During planting, air seeders can also contribute to seed damage, particularly when airflow rates are inaccurate. “If you have a larger seeder, you’re probably going to have to run the fan a little faster in order to get the distribution to all the shanks,” he said. “And that’s where the challenge comes in. You want to increase your speed, but you don’t want to increase it too much that you’re damaging the seed. And you don’t want to decrease it too much because then you might plug your system.”

Some producers have found clever ways to first test their air seeders first to make certain they’re not damaging seed during the planting process. They remove one of the hoses off in the corner of the planter and duct tape a sock around the hole. After running the planter for 100 feet or so, they remove the seed and soak test it to see if the seeder is causing further damage.

“There’s nothing worse than knowing that you have 90 per cent germ seed, but because you have dry seed and put it through your air seeder — if you’re not careful with airflow rates, you can damage that seed even more,” said Lange.

“You don’t have to do this every year,” he concluded. “But it’s years when you know there are dry seed issues — if you want to compensate for that, that’s one thing a farmer can do.”

About the author


Melanie Epp

Melanie Epp is a freelance farm writer.



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