Dr Michelle Hubbard a Research Scientist with Agriculture and Agri-Food Canada in Swift Current is working with a team of researchers across the prairies to try and find out what's happening.

The emerging health issue first started showing up on chickpea plants in 2019 in the Assiniboia and Coronach areas.

The symptoms vary from leaf tip chlorosis and wilting all the way to complete plant death.

Hubbard and her team have been working on several possible causes from ascochyta blight, to root rot, wilt disease, viruses, herbicides, nutrient stress, nematodes, nodule feeding insects to drought followed by moisture and healthy versus unhealthy soils.

Since the issue was first identified samples have been taken every year from a variety of fields and site trials where the chickpea health issue has been showing up.

She says that based on the year, variety, and conditions they've developed a scale identifying a wide range of symptoms from 1 which shows early signs of a problem, all the way to 5 which is plant death.

A 2021 survey done by Dr. Sabine Banniza - a University of Saskatchewan researcher - found a soil-borne fungus 'verticillium dahliae' in root samples of some of the affected chickpeas plants, however, there have also been numerous samples taken from plants showing the symptoms that did not have the verticillium dahliae present.

Scientists are working with producers as well as doing work both in field trials and greenhouses to try and replicate the health issue and possible cause. 

She points out they are still waiting on data that looks at variety selection to see if one variety may be more susceptible.

While the issue was first found in the southwest, regional variety trials in 2023 also found symptoms showing up on chickpea plants in Redvers and Saskatoon.

Hubbard says while they've been looking at several potential factors nothing has been confirmed and more work needs to be done.

"What it really looks like is a wilt pathogen, like something that's clogging the vascular system. It looks like something that's cutting off the circulation of nutrients to the above ground material. And so there's a Fusarium oxysporum subspecies that could cause that, or verticilliums that could cause that. So we have a good idea of what fungi should cause that. but when I've received these fresh samples that look like they have wilt, we've plated leaves, we've cut into the stems looking for the visual symptoms of the vascular system being plugged and never found it."

On top of all the other work being done, they've also extracted DNA from the infected plants to have that analyzed and they've found no differences between the healthy plant and the diseased plant and no pattern that makes any sense as to a possible explanation.

While no solid solutions have been found, researchers continue chipping away at the issue and any possible causes.

She notes we are not the only ones dealing with this,  the emerging health issue is also showing up in chickpea fields to the south of us in the U.S. as well as Australia, but they also haven't been able to identify what the root cause is and how to deal with it.

Hubbard updated producers during the Sask Pulse Regional Pulse Meeting in Swift Current last week.