It may already be too late for this year’s crop, say many plant scientists and agrologists in Saskatchewan.
Lentils seemed to be a good choice for growers this year. They fit the rotation, command a reasonable price and thrive under the predicted El Nino-caused, hot and dry conditions. But then conditions turned hot and wet and the fungus anthracnose began its ascent up the stems of lentils.
“I’ve heard about it being in fields from Regina to Rosetown,” said Al Slinkard, of the University of Saskatchewan. “Anywhere the conditions were right. The inoculum was always there but the conditions weren’t. It is hot and wet with a closed-in crop canopy and that is when you get anthracnose.”
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Farmer reports of the problem began last week. Agrologists began diagnosing the fungus and making recommendations. They could spray with fungicide (Bravo) if flowering had yet to begin or was in the early stages, or look to other options if the plants were more advanced and large numbers were affected.
Growers should look for brown lesions on the stems that work upward and girdle the stem. For many crops it will already be too late, said Lone Buschwaldt, a research scientist with Agriculture Canada in Saskatoon.
Provincial crop disease pathologist Mike Celetti says the calls from farmers and extension agrologists have kept him busy – “24 calls this morning alone.
“A lot to do with anthracnose but we really don’t know how serious a problem it is yet,” said Celetti.
“If the producer is going to spray then he will need to penetrate the plant canopy. To do this he must keep up the water rates so that the product will fully penetrate the canopy. In the 15 to 20 gallon range of water should do it.”
Buschwaldt said that based on work she did in Manitoba on anthracnose in lentils, unless farmers spray at the earliest flowering stage it won’t be effective in controlling the disease.
“After that you might as well look to controlling (the inoculum) and prepare for coming years.”
She recommends that producers not plow down the crop or its harvest residue because this could help the fungus survive.
Slinkard suggests producers might consider baling the crop as soon as it is determined that it will not be viable for seed.
“There is a demand for greenfeed this year and farmers may as well get something out of it,” he said.
Determining the economic threshold for destroying a crop is not clear.
“If you can see it in a lot of plants in the field then it will be in most of the rest of them,” said Slinkard.
In the future there may be some help, said Buschwaldt.
“I brought with me from Manitoba some of the germ plasm we developed that has some resistance built into it. No commercial varieties now have it but with some breeding we can develop resistance in new ones. And every year is not so hot and moist. It isn’t all bad news but for growers that have this problem, it may already be too late for them this year,” she said.
Alberta remains anthracnose-free, according to provincial plant pathologists in that province.
