A comparison of clubroot development and management on canola and Brassica vegetables

Abstract

A comparison of clubroot development and management on canola and Brassica vegetables, Canadian Journal of Plant Pathology, 35:2, 175-191, Abstract: Clubroot of canola was identified for the first time on the Canadian prairies in 2003, and is spreading rapidly across the region.Although clubroot has been studied extensively on vegetable Brassica crops, it was not clear initially how much of the information would be directly transferable from the intensive production of vegetable crops to the extensive production practices used for canola. This review examines similarities and differences between clubroot development and management on vegetable crops and canola. One important difference was that clubroot generally has a larger economic impact on canola, which is harvested for seed, than on vegetables, especially those where early vegetative growth is the marketable component. Also, clubroot has spread within the production area more quickly than was expected based on vegetable production. This occurs in large part because the resting spores are readily moved within and between fields on the heavy machinery used for canola production, but movement of spores by wind and water is also being assessed. Interestingly, crop rotation to reduce yield losses may be a more viable approach for canola than in vegetable production. Resistance to clubroot is the most consistent and economically viable approach to clubroot management in canola, but several lines of evidence indicate that this resistance may not be durable. Fortunately, the large acreage of canola production in Canada ensures that new sources of resistance will be developed and deployed as existing sources are eroded. Pathogen development and cultural control are very similar on vegetables and canola; bait crops and soil amendments are generally not commercially viable in either system; and biocontrol has a limited potential at this time. Manipulation of seeding date, application of fungicide, and soil fumigation generally have more potential for use in vegetable production than for canola. Identification of approaches that reduce disease pressure in clubroot-infested fields and increase the durability and diversity of genes for clubroot resistance represent important lines of future research.Résumé: La hernie des crucifères a été détectée pour la première fois dans des cultures de canola sur les Prairies canadiennes en 2003. Cette maladie continue d'envahir la région à un rythme accéléré. Cette maladie a fait l'objet de nombreuses études chez les cultures maraîchères du genre Brassica et nous ne savions pas, initialement, quelles informations dérivées de la production intensive des cultures maraîchères seraient pertinentes pour la culture à grande échelle du canola. Cet article de synthèse examine les similitudes et les différences entre l'évolution et la gestion de la hernie chez les cultures maraîchères et le canola. Une différence importante est le plus grand impact économique de la hernie sur le canola, qui est cultivé pour sa graine, que sur les cultures mar...

Soil Factors Related to the Severity of Clubroot in Rio de Janeiro, Brazil

“…Increased levels of soil OM have been reported to decrease the severity of clubroot, although conflicting results have been obtained (Gossen et al 2013). However, in the present study, high levels of soil OM were observed (9.65 to 58.44 g/kg soil), with similar mean values for the two groups.…”

“…botrytis L.), bok choy (B. pekinensis L.), broccoli (B. oleracea L. var. As the disease progresses, there is a reduction in the effective root system of the plant and, consequently, a reduction in the water and nutrient absorption process, which leads to the appearance of secondary symptoms, such as wilting during the hottest hours of the day, stunting, and reduced biomass production and commercial quality of the vegetables (Gossen et al 2013). The life cycle of P. brassicae is complex and can be divided into two phases: i) germination of the resting spores under stimulation from root exudates of host species, release of the primary zoospores, and subsequent infection of the root hairs; and ii) colonization and proliferation of the pathogen in the cortex of the roots and subsequent formation of root galls (Niwa et al 2008).…”

“…Increasing the pH to values equal to or greater than 7.2 is recommended for controlling clubroot. High levels of organic matter (OM) in the soil have also been associated with suppression of and reduction in losses due to clubroot; however, there are conflicting reports (Dixon 2014;Gossen et al 2013). High levels of organic matter (OM) in the soil have also been associated with suppression of and reduction in losses due to clubroot; however, there are conflicting reports (Dixon 2014;Gossen et al 2013).…”

Cytology of infection, development and expression of resistance to Plasmodiophora brassicae in canola

“…(Tewari et al ., ). By 2007, the pathogen had become established in an extensive region around the initial area of infestation and is considered to be a threat to the entire Canadian canola industry (Strelkov et al ., ; Gossen et al ., ).…”

Liming and biofungicide for the control of clubroot in cauliflower1

“…roots (Usuki & Narisawa 2007). This characteristic may limit the use of traditional rhizosphere-colonizing microorganisms with potential for clubroot management (Gossen et al 2013).…”