Agronomy Library > Soil Conservation

Perennial Weed Control in Direct Seeding Systems
Author: Mirza N. Baig, Shaffeek Ali and Peter Gamache
Date Created: April 21, 2004
Last Reviewed: April 21, 2004

Perennial weeds live for at least two years and often many more. They reproduce and/or spread by underground creeping rootstocks, rhizomes or tubers, as well as by seed. These reproductive strategies are one of the reasons these weeds are difficult to control in conventional and reduced tillage systems. Perennial weeds are very competitive, and if they are not controlled, they reduce crop production. In recent years, there has been a dramatic increase in the incidence of perennial weeds in Alberta (Table 1). For example, in the Alberta Weed Survey (1987-89), Canada thistle was ranked 12th, occurring in 35% of fields; by 2001 its was ranked 4th, and occurred in 41% of fields (Thomas et al 1997). This change in the relative abundance ranking in that 14-year time period may be due to the adoption of reduced tillage practices, continuous cropping, weather, and diversified crop rotations. The objective of this fact-sheet is to discusses ways to manage perennial weeds in reduced tillage systems using integrated pest management techniques. 

Click on the above pdf to download a detailed 9 page factsheet.