Using surveys and science to detect regional pathogens aren’t new methods to detect diseases in pulse crops, but how are our U.S. pulse crop growing counterparts dealing with the diseases present in their areas?

In this Pulse School episode, Lyndon Porter, research plant pathologist with the United States Department of Agriculture, joins Kara Oosterhuis to discuss root rot research carried out in the U.S.

“Some of the work that we’re doing currently is looking at root rot in lentils, caused by fusarium,” says Porter, adding that there are many fusarium species that can cause problems for pulse crops. Fusarium avenaceum is the primary root rot pathogen in Canada and the U.S. and is the focus of Porter’s work.

In Montana and North Dakota, the root rot issues are very similar to what Canadian growers are dealing with — there’s sharing of information and material that may have genetic resistance to pathogens, says Porter.

“I work with a lot of pulse breeders and I screen a lot of what’s called germplasm, or genetic resources, from all over the world and try to identify genes that might be present in these different lines with resistance to these different root rot pathogens,” Porter says.

When it comes to mitigating root rots, Porter says that the collaboration with chemical companies for using seed treatments to manage root rots and with organizations to share survey information is key to knowing which pathogens are a concern, and where. One pathogen in particular that sticks out in some U.S. regions that isn’t so prominent in Canada is fusarium solani.

“We really have to conduct surveys to know what’s there and so a misconception is sometimes growers just want to assume, and maybe even scientists, that maybe a particular pathogen that’s caused problems elsewhere is the major problem in other ares,” says Porter.

Surveys will confirm if the pathogen is widespread, and then management strategies can be catered to the area.

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No conversation about root rots in pulse crops is complete without mentioned aphanomyces, which is present in both countries. Porter emphasizes that there are synergistic effects between fusarium and aphanomyces, something that’s been confirmed in Canada. In general, under dry conditions, Porter says that fusarium dominates, and under wet conditions it’s aphanomyces that’s the main concern.

Other biotic issues that make root rots worse in the U.S. are nematodes, that can compound problems in certain fields — they cause wounds in roots that allow other fungal problems invade. Contending with wireworm and seedcorn maggot is also a problem down south.

Porter’s main research pulse species are field pea and lentil, but he is getting into chickpea research as well.

Finally, Porter says that funding into root rot pathogen research and being able to customize management strategies for specific pathogens is much appreciated and is critical for the USDA’s research programs.

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