Farmers have heard the word Fusarium in relation to small grains and problems with DON or vomitoxin. However, the term actually refers to a large genus of soil fungi, some of which target other plants, among them, lentils and peas.
While the species that cause root rots in peas and lentils are different from the species that causes DON or vomitoxin in wheat, the pathogens are no less devastating to lentil and peas.
Plant pathologist Dr. Mary Burrows, director of the MSU Extension’s Shutter Diagnostic Laboratory, is part of a three-state collaboration that’s digging into the fusarium complex that causes root rots in peas and lentils.
The study started with a survey of 25 fields in each of three states, Montana, North Dakota and Washington. Soil samples were taken to determine which fusarium species are present. The information developed from the soil surveys will be used to develop varieties that are resistant to root rots.
Producers at each location were also asked about their management practices, to see if any particular practice is tied to what was found in the soil.
“(Fusarium root rots) are not new, but they are really complex,” Burrows said. “There are probably six to eight species causing root rots, and we don’t know which are the prominent species in Montana.”
As more and more pulse crops are being grown, however, the diseases that affect those plants are becoming more and more prevalent throughout the region.
Burrows is among those who sounded an early warning call at pulse crop conferences, warning that pulse crop diseases are on the horizon. She has since been active in regional efforts to develop both better disease management and resistant varieties.
Burrows urges growers to continue practicing good crop rotations for pulses, particularly as there are still no resistant varieties available. There should be at least three to four years in between growing cycles for lentils, chickpeas, peas and dried beans, which are the most common pulse crops grown.
Seed treatments are also available and may help. Some.
“They only last two to three weeks after planting, though,” Burrows added. “Fusarium can occur after that, so the efficacy is limited.”
The amount of rain in some areas of the region is boosting the likelihood of disease problems with root rots in lentil and peas, and creating conditions ripe for Ascochyta and Botrytis or grey mold, according to an alert Burrows put out recently. Later in the season, white mold is expected as well.
Burrow’s efforts are not the only ones in the state. A second thrust in the root rot investigation is a study on agronomic practices, including nutrition, roll timing, seed treatments, and variety trials.
That study is being conducted at four research centers in Montana, including Sidney’s Eastern Agricultural Research Center, and at three centers in North Dakota, including Minot, Hettinger and Carrington.