Impact de l’hernie des crucifères [Plasmodiophora brassicae] sur la productivité et la qualité du canola

Abstract

Clubroot, a disease caused by Plasmodiophora brassicae, first appeared in canola fields in Quebec in 1997. The objective of this project was to assess the impact of a soil infested with P. brassicae on the productivity and grain quality of canola. In 1998 and 1999, 31 cultivars in total (23 of Brassica napus in 1998 or 25 of B. napus in 1999 and 6 of Brassica rapa) were evaluated. In 2000, 25 cultivars and two lines (70584 et 70585) of B. napus and 6 cultivars of B. rapa were tested. These cultivars or lines were sown on a soil where P. brassicae had been prevalent for a few years and on another soil which had never been sown with a cruciferous crop before. The soil infested with P. brassicae reduced canola productivity. Grain yield losses were 80%, 91%, and 85% in 1998, 1999, and 2000, respectively, for the Argentine cultivars (B. napus). In the Polish cultivars (B. rapa), yield losses were 69%, 96%, and 89%, respectively, for the same years. Clubroot also reduced straw yield, oil content of the grain, and the grain mass. As opposed to overall B. napus cultivars, the two lines of B. napus appeared to be resistant to clubroot in 2000. Grain yields of these two lines were not affected by the disease. Since there is no registered canola cultivar tolerant or resistant to clubroot in Quebec, agronomic practices used to prevent or reduce the incidence of the disease should be encouraged.

Keywords:

• canola
• Brassica napus
• Brassica rapa
• clubroot
• Plasmodiophora brassicae
• yield
• grain quality