Clipping Weeds Above The Crop Canopy Reduces Seedling Recruitment

E. N. Johnson¹ and G. Hultgreen ²

Weed control is a challenge for organic growers. Organic growers rely on crop rotation, cultural practices and mechanical weed control to control weeds. Some organic producers have experimented with clipping weeds above the canopy of short stature crops such as lentil or flax. A field experiment evaluating clipping at various stages of weed development was conducted over three years (1999-2001) at Scott, SK. The clipping was done above a lentil crop canopy with a gas-powered hedge trimmer. The Prairie Agriculture Machinery Institute at Humboldt modified the cutting component of a self-propelled swather and carried out field trials on four farmer's fields. At Scott, weed clipping did not result in a detectable lentil yield increase in either year. Clipping in 1999 reduced wild oat emergence by 64% in the spring of 2000 if clipping was done after wild oat heading. There was a trend towards lower wild mustard seedling recruitment if clipping was done at the podding stage, however differences were not significant. In 2000, wild oat populations were low and clipping had no detectable effect on 2001 recruitment. Clipping at any broadleaf weed stage past flowering in 2000 resulted in a 95 and 85% decline in wild mustard and common lambsquarters recruitment, respectively in the spring of 2001. The PAMI field trials resulted in an average of 80% reduction in wild oat recruitment the year following clipping. Weed clipping may have potential as an integrated weed management practice for organic producers.

See poster in PDF format


Source
2nd OACC Organic Research Workshop, Presented in association with the Organic Connections: Prairie Wide Organic Conference and Trade Show, November 14-16th, 2004


Author Locations & Affiliations
(1) Agriculture & Agri-Food Canada, Scott, SK. *Correspondence: johnsone@agr.gc.ca
(2) Prairie Agriculture Machinery Institute, Humboldt, SK.


en français