Last year, Manitoba’s flax crop averaged a disappointing 19 bushels an acre, not far off the 10-year average of 20.
But there are ways to boost flax yields, says Anastasia Kubinec, an oilseed specialist with Manitoba Agriculture, Food and Rural Initiatives.
A survey of farmers who grew above-average-yielding flax found they planted at least 40 pounds of seed an acre and seeded no deeper than one inch, Kubinec told the Manitoba Flax Growers Association’s annual meeting here March 3.
They also seeded their flax before the fourth week of May. Not every crop can be seeded at the optimum time, but flax is often seeded last.
Manitoba research shows delaying flax seeding until June 1, 10 or 20 cuts yields seven, 29 and 52 per cent, respectively compared to seeding in early May, according to the Flax Council of Canada’s website.
“Late seeding also reduces oil content and seed size,” the flax council says. “Because green stems and second growth are more prevalent in a late-seeded crop, harvesting is more difficult.”
Flax needs to be sown into fertile soil. Sixty pounds of nitrogen is optimum, Kubinec said.
Too much nitrogen can cause flax crops to lodge.
Phosphorus is also critical, especially during the first two weeks of growth. “After that it doesn’t have much effect on yield,” Kubinec said.
Mycorrhizae, a type of fungi found in the soil, helps flax roots to spread, assisting the plant take up phosphorus.
“In exchange the flax actually feeds the mycorrhizae carbohydrates to keep it alive,” she said.
Crops such as wheat, barley and oats also have the same symbiotic relationship with mycorrhizae. Canola does not.
“It will actually not work with the mycorrhizae and in a year of canola the mycorrhizae go down,” Kubinec said.
As a result, flax grown following canola will yield 10 to 15 per cent less than following other crops, she said.
Disease can reduce flax yields too. Pasmo is fungal infection that overwinters in the soil on infected flax stubble.
Pasmo can cause defoliation, premature ripening and can weaken the infected flower stems resulting in heavy boll drop during rain or wind. Depending on the earliness and severity of the infection, pasmo reduces yields as well as seed and fibre quality.
In 2009 Headline fungicide was registered for pasmo control in flax. Some farmers complain the fungicide delays the crop’s maturity. BASF, the maker of Headline, says the fungicide is protecting the crop from disease so it lives longer.
– ANASTASIA KUBINEC