Study of the effects of Brassica root architecture and fertilizer application on clubroot disease severity and yield

The Challenge

Clubroot of canola is a major threat to canola production in Canada. Although the disease targets the plant roots, not many studies in clubroot have focused on root traits or how nutrients like nitrogen may influence infected roots.

The Project

Examine the role of root architecture and nitrogen supply on both the severity of clubroot disease and root traits to determine if root-type is an important trait to consider for clubroot resistance, understand the effects of nitrogen levels on clubroot resistance, and create a foundation for understanding genetic control of root morphology.

The Results

Clubroot symptoms developed 5 to 10 days earlier in plants fertilized with nitrogen, phosphorus, and potassium at recommended and higher rates compared to unfertilized plants. However, after 8 weeks, no significant differences in clubroot severity were observed. Conversely, fresh and dry gall weights significantly increased in the two treatments with fertilizer compared to the unfertilized treatment. Plant height, number of branches, and silique count were also significantly higher in fertilized treatments, indicating improved yield parameters with fertilizer application, despite clubroot presence.

Overall, fertilizer application significantly enhanced yield parameters, while also accelerating the onset of clubroot and promoted larger galls.

Grower Benefits

Results of this study could positively impact the development of new clubroot resistant varieties and aid in minimizing clubroot spore loads, reducing clubroot infection and input costs.