Vegetative propagation and regenerative capacity of Canada thistle and sow thistle under organic management

Description

Canada thistle and sow thistle are the worst perennial weeds in organic field crops. Mechanical weeding methods commonly used to control annual weeds do not work on perennials. Integrated management methods for these weeds are lacking and there is very little information on their vegetative propagation and ability to regenerate under our conditions.  The purpose of the project was to study the vegetative propagation and regeneration capacity of Canada thistle and sow thistle with a view to developing effective weed control strategies. The data from this study was used to identify biological behaviors that can be used in managing these perennials under Québec growing conditions.

Objective(s)

• Determine the minimum regenerative capacities of both species to identify when they are the most vulnerable to weed control methods, i.e., when their root reserves are at a minimum
• Determine the effect of fallow periods to develop a strategy to reduce the proliferation of these weeds
• Determine their vegetative propagation by evaluating the spatial distribution of their roots
• Evaluate the physical damage to both species caused by different types of soil tillage equipment, to help growers decide which equipment to use and when to achieve maximum control of these perennials