Non-Peer ReviewedField pea (Pisum sativum L.) is an important grain legume in Western Canada. Growers can, however, be reluctant to include pulse crops in their rotation because they are poor competitors with weeds. Developing more competitive field pea cultivars is important to ameliorate weed competition. The identification of competitive cultivars and the traits conferring competitive ability should lead to the development of more competitive field pea cultivars. The objective of this research was to evaluate the ability of semi-leafless field pea cultivars to suppress and withstand weed competition and to identify traits that may confer competitive ability in field pea. Field experiments were conducted in 2012 at Floral, Saskatchewan and St. Albert, Alberta. Fourteen semi-leafless field pea cultivars with divergent pedigree, vine length, seed size, and market classes were seeded at a target density of 75 plants m-2 under weedy and weed-free conditions. Imidazolinone-tolerant wheat (c.v. CDC Imagine) and canola (c.v. 45H73) were planted as pseudo weeds at a target density of 20 plants m-2 in the weedy plots. Variables measured were leaf area index, plant height, pea biomass, weed biomass, pea yield, and weed seed production. Data were subjected to ANOVA using the mixed model procedure in SAS. There was no cultivar by treatment interaction for pea yield at Floral, so cultivars did not differ under treatments. CDC Dakota produced the greatest pea yield and Reward produced the poorest pea yield. CDC Dakota was among the best for pea biomass production at both sites, compared to CDC Leroy, which was among the worst at both sites. CDC Dakota was also among the best for the low weed seed production at Floral. CDC Mozart, CDC Patrick, and Cutlass were among the best at Floral for ability to withstand competition at Floral. While, CDC Dakota, CDC Meadow, and CDC Patrick were among the best for their ability to compete at Floral. At both sites, no correlations were strong enough to show which traits are conferring competitiveness in semi-leafless field pea cultivars
