Here are key findings from four years of work on nitrogen application, seeding rates, herbicide formulations and disease management.
Between 2010 and 2016, the acreage of Clearfield lentils grown in Alberta increased by a factor of seven. With strong global demand for lentils, the province’s growers went all out to meet it.
For most of that period, Robyne Bowness Davidson was working just as diligently to meet farmers’ demands for agronomic information on how best to grow the crop. Between 2012 and 2016, with funding from Alberta Pulse Growers through the Alberta Crop Industry Development Fund, she conducted field research on four core agronomic issues.
Nitrogen application. Pulse crops fix nitrogen so, in general, starter nitrogen shouldn’t be needed, provided the crop is inoculated. This guideline might not apply in the same way with red lentils, however, which have a smaller root system than other pulses. Bowness found that some starter nitrogen is helpful, but too much can hold the crop back.
“They need just a little bit to get them going, until the root system is established and nitrogen can be fixed,” said Bowness Davidson, Lacombe-based Pulse Research Scientist with Alberta Agriculture and Forestry. “But if there’s too much nitrogen, it won’t nodulate. And yes, you need to inoculate.”
Seeding density. Growers in Saskatchewan – old hands at lentils, after all – target 120 plants per square metre. Is this right for Alberta too? Seeding this heavily can be expensive but, as Bowness demonstrated, it’s worth it. “We found that in a year with adequate moisture you can increase the seeding rate and it will increase the yield in a worthwhile way,” she said.
Herbicide formulation. The imidazolinone herbicide family, to which Clearfield lentil varieties are resistant, is available in several formulations. Bowness Davidson studied the effectiveness and crop safety of these formulations and found little difference in weed control and plant health between them.
“Which herbicide formulation is best depends on the year and the soil zone,” she said, “but they are all working.”
Disease management. The fourth element of Bowness’s project was to compare the susceptibility of different Clearfield red lentil varieties to root rots and sclerotinia.
“We wanted to put Clearfield red lentils out there against large green lentils and see whether the disease picture is any different,” she said. “It turns out the diseases are so random, sporadic and climate-dependent that there is no major difference between varieties.”
Should you grow Clearfield red lentils? It’s an agronomic decision with many moving parts. Based on the findings from this project and others, Bowness Davidson developed an information tool that guides growers through 12 questions and helps them land on the right decision for their operation.
With lentil demand surging worldwide, and Alberta farmers equipped with valid agronomic information, Bowness Davidson sees lentils increasing in prominence in growers’ crop rotations.
“Red lentils are now being seen everywhere in Alberta,” Bowness Davidson said. “We need to make sure that farmers can grow these crops. The role of this project was to help them and give them options.”
Project at a glance
Project title: Evaluation of the effect of nitrogen rates, seeding rates and herbicide applications on production of Clearfield red lentil in Alberta
Project lead: Robyne Bowness Davidson, Alberta Agriculture and Forestry
Total value of project:
Start date: April 1, 2012
Completion date: May 31, 2016