crop news
clubroot
Soil fumigants show potential for controlling clubroot in canola but costs may be prohibitive, those at the Jan. 21 Agronomy Update in Lethbridge were told.
Sheau-fang Hwang, a plant pathologist with Alberta Agriculture, has conducted several years of tests on the efficacy of metam sodium in controlling clubroot, a soil-borne disease that has been slowly spreading in Alberta and into Saskatchewan and Manitoba.
Hwang has tested the fumigant, with the brand name of Vapam, in greenhouse trials and smaller field tests.
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She found the product effective against clubroot even at reduced rates in greenhouse trials.
She also found significant reductions in clubroot in 2012 and 2013 field trials, in which Vapam was incorporated into the soil and packed seven days before seeding.
Hwang said she was encouraged by the results, but the chemical is expensive. It may not be economically feasible to treat a field, but it might be possible to treat field entrances where clubroot infection is high or infection hot spots in fields.
Vapam is registered in Canada for use on tomatoes, potatoes, gingseng and other horticultural crops, but application requires specialized training.
Hwang found that it reduced clubroot severity and infection rates when applied at soil moisture levels in the 10 to 30 percent range.
A paper she published on its use concluded: “Vapam can effectively reduce clubroot severity and may be useful for the treatment of transplant propagation beds in brassica vegetable production and for the containment of small, localized clubroot infestations in commercial canola crops.”
