Trials Hemp was tested in several locations last year, but more site years are needed for recommendations
Manitoba has been conducting hemp agronomy trials at research stations across the province for several years, and thanks to a grant of $70,000 from the Canadian Hemp Trade Alliance, this year trials were expanded to other provinces.
“If you get enough site years, then the data starts to mean something,” said Keith Watson, a diversification specialist with Manitoba Agriculture.
Watson told a recent meeting of the Canadian Hemp Trade Alliance conference that data needs to be used with caution and more research is needed before recommendations can be made.
This year, Manitoba research stations included Arborg, Gilbert Plains, Carberry and Melita. Trials were also done at Vegreville, Alberta, Kemptville, Ontario and Melfort, Saskatchewan.
Watson said seeding rates for hemp need to be high enough to allow producers to get good fibre and grain yields. Researchers had a target population of 250 seeds per square metre. They measured the seedlings when the plants were two to four inches out of the ground and found only 25 per cent had emerged. This loss represents a huge cost to producers, who will need to bump their seeding rates.
“There’s a lot of research we need to do to figure out why we get the plant population we do. It is normal in all crops to have a mortality rate, but hemp’s is particularly high,” said Watson.
Researchers began at rates 25 seeds per square metre and increased to 350. Results showed about 150 seeds per square metre gave the best yields for dual-purpose fibre and grain varieties. There still isn’t enough research on the varieties to prove which varieties are outstanding, Watson said.
Researchers also measured seed size, which is important to know because it has an impact on seeding rates. “In order to get the right population, you have to adjust accordingly,” said Watson. Researchers tested seed treatments Gemini and Raxil to try to reduce mortality rates. They did increase plant establishment and coverage in some of the locations, but not others.
However plant population was not directly related to yield.
“We can have a pretty thin stand of hemp, but we end up with huge heads and can end up with the same grain yield,” Watson said.
Researchers also tested fibre yields. Each variety and location included in the trials has to be THC tested, which represented a significant cost to researchers, said Watson.
Recommendations for fibre agronomy and characteristics are difficult to determine as there is no commercial processor for hemp fibre in Canada and these specs are defined by the market. Any current fibre being used is a byproduct after a grain harvest, said Watson.