Green manure crops could help potato growers manage scab and rhizoctonia, said University of Saskatchewan researcher Jill Thomson.
Speaking to the Saskatchewan Seed Potato Growers Association conference in Saskatoon Nov. 19, Thomson detailed studies begun this year at the university using a host of green manure crops with Norland and Penta potatoes.
The plots planted two types of mustards (AC Vulcan and AC Pennant), canola and annual ryegrass crops. The research plan is to plant and incorporate the organic matter into the soil the summer before potatoes are planted there.
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Thomson said changing the soil environment alters the balance of microorganisms, causing compounds to interact with microorganisms.
“They may kill off good guys as well as bad guys,” she said.
Similar studies in Maine saw decreases in common and powdery scab using mustard and a reduction of rhizoctonia using rapeseed. Rhizoctonia appears as black dirt marks on potatoes that affect tuber roots and stolons.
“You may not see drastic reductions but it may eat away at those reservoirs of disease,” said Thomson. “That’s where we really need something for the growers,” she said, noting current lack of control methods for scab.
Preliminary results from the university’s research, funded through 2005, will be available in the new year.
If results are encouraging, Thomson will be looking for farmers interested in establishing green manure crops in their fields this coming summer for potato trials next summer.