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Vigour tests recommended for wheat and barley

Last fall’s harvest may have left some wheat and barley seed less than ideal

Poor harvest conditions can create poor seed quality, and in some cases affect germination and vigour. As a result of last year’s harvest conditions, seed analysts are seeing a wide gap between germination and vigour in Western Canadian wheat and barley seed. Analysts are urging growers to test seed so that they can take action, if necessary.

In Western Canada, soil conditions are not always perfect for planting come spring, but a short growing season makes it sometimes difficult to wait for ideal conditions. Under less than ideal circumstances seeds may still germinate. But without vigour — the crop’s strength and vitality — that crop could still fail.

In a recent interview, Sarah Foster, senior seed analyst at 20/20 Seed Labs, said seed analysts are seeing as much as a 40 per cent spread between germination and vigour. “We like to see no more than a difference of 10 per cent between germination and vigour,” she said.

The gap has mostly been found in wheat and barley seed produced in central and northern Alberta, Foster said.

Germination and vigour explained

Foster explained how germination studies are conducted in the lab. A germination test is the base test that establishes field-planting value under favorable field conditions, Foster explained. “It’s very difficult to assess if seed has issues if it grows normally, and one expects the vigour will be good too,” she said. “The vigour test stresses the seed so if there is a problem that’s not detected in the germination test we find it in the vigour.”

Wheat, she said, is tested at a constant 20 C between paper blotters or in sand for seven days. There is often a four-day interim count. If dormancy is present then there is a pre-chill period of three days at 7 C before the germination period at 20 C. Vigour is tested at 5 C on paper in a sealed plastic box. It is held at that temperature for 12 days.

Results this year can be attributed to a number of causes, but namely poor harvest conditions poor harvest conditions. Foster thinks seed either chitted or sprouted, or came off the field too immature. When seeds sprout, poor development can be expected, as the seed has used much of its food and energy reserves. “Also root tips can be necrotic because they are exposed and weathered,” she said. “Immaturity causes seed to not be physiologically mature so there is a higher level of abscisic acid that prevents germination under stress.”

“This means there is a lower concentration of gibberellins, which are needed for germination to occur,” she continued. “The seed quality this year has been affected and it’s apparent that under stress there are low vigour results.”

Pam de Rocquigny, one of two general managers for Manitoba Corn Growers Association and Manitoba Wheat and Barley Growers Association, expects there will be problems with disease as well this year.

“We had high disease pressure last year in terms of fusarium head blight,” she said. “Of course, that can have an impact on the quality of seed that you’re intending to keep for planting this spring.”

Foster agrees. “We are doing lots of DON testing,” she said. “The mycotoxins have been quite high in durum.”

So what can growers do to mitigate problems? De Rocquigny encourages growers to get seed tested at an accredited lab. “If there are issues and concerns with it they have the ability to either condition and re-test it or secure another seed source for planting in 2017,” she said. “You have one chance to set the crop up for success, and securing a good quality seed lot is one of those first steps.”

De Rocquigny suggests calling either Sarah Foster at 20/20 Seed Labs or Holly Gelech at BioVision Seed Labs.

Foster said it’s important that growers get a vigour test that is truly representative and timely, one that is closest to the planned date of planting. “Use the vigour as your seeding rate number and get a 1000 kernel weight,” she said. “Use seed treatments and seed into warmer soils. If the seed vigour is lower than 60 per cent and has dormancy, think about new seed.”

“There is good quality seed out there that has good germination, good vigour,” said De Rocquigny. “I always like to remind producers that it’s not all doom and gloom.”

About the author

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Melanie Epp is a freelance farm writer.

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