Impact of lamb’s-quarters, common ragweed and green foxtail on yield of corn and soybean in Ontario

Abstract

Weaver, S. E. 2001. Impact of lamb's-quarters, common ragweed and green foxtail on yield of corn and soybean in Ontario. Can. J. Plant Sci. 81: 821-828. Field studies were conducted in Harrow, Ontario, from 1990 to 1993 to quantify the relationship between yield of field corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] and density of lamb's-quarters (Chenopodium album L.), common ragweed (Ambrosia artemisiifolia L.), and green foxtail [Setaria viridis (L.) Beauv.]. Experiments were conducted separately for each weed and crop combination. Weeds emerged at the same time as or within a week of the crop. Coefficients of the rectangular hyperbolic damage function were estimated for each year and pooled over years. In both crops, lamb's-quarters was the most competitive of the three weed species, and green foxtail was the least competitive at low densities. Maximum yield loss at high weed density varied with weed species in field corn, but not in soybean. The estimated competition coefficients of the damage function have been incorporated in a decision support system for integrated weed management in Ontario. Les adventices lèvent en même temps que la culture ou dans la semaine qui suit. L'auteur a estimé les coefficients de l'hyperbole rectangulaire servant à évaluer les dommages chaque année avant d'en faire la moyenne. À faible densité, le chénopode blanc est l'adventice la plus compétitive dans les deux cultures, la sétaire verte se trouvant à l'autre extrémité de la courbe. La baisse de rendement maximale à une forte densité d'adventices varie avec le type de mauvaise herbe dans les champs de maïs mais pas dans ceux de soja. Les coefficients de concurrence estimatifs des adventices ont été ajoutés à la fonction utilisée pour évaluer les dommages en vue d'élaborer un système qui permettra d'étayer les décisions relatives à une lutte intégrée contre les mauvaises herbes en Ontario.

Multiple introductions, admixture and bridgehead invasion characterize the introduction history of Ambrosia artemisiifolia in Europe and Australia

“…A full‐grown A. artemisiifolia plant can produce large quantities of seed that can stay dormant for many years (Bassett & Crompton, ). This species is an agricultural pest and has significant effects on crop productivity with competition experiments showing yield losses in corn and soya bean reaching 70% (Brandes & Nitzsche, ; Weaver, ). Its wind‐spread pollen is a leading cause of hay fever worldwide (Laaidi, Laaidi, Besancenot, & Thibaunod, ).…”

Glufosinate Antagonizes Clethodim Control of Goosegrass (Eleusine indica)

“…Weaver (2001) reported an I value of 0.7 (compared with 39.7 in this study) and an A value 80% with green foxtail densities ranging from 500 to 600 plants m À2 . Volunteer corn may be more competitive than other grass weeds because of its taller growth habit and wider leaves compared with other grasses.…”

Control of volunteer adzuki bean in soybean

“…For example, Barrentine [7] concluded soybean seed yield can be reduced by 10%, 28%, 43%, and 52% in the presence of Xanthium strumarium L. (common cocklebur) at densities of 3300, 6600, 13,000, and 26,000 plants ha −1 , respectively. A study conducted by Weaver [8] evaluated the effects Chenopodium album L. (common lamb'squarters), Ambrosia artemesiifolia L. (common ragweed), and Setaria spp. (green foxtail) on the yield of soybean.…”

“…(green foxtail) on the yield of soybean. Soybean yield was reduced up to 75%, 70%, and 80% by high densities of Chenopodium album, Ambrosia artemesiifolia, and Setaria spp., respectively [8]. Abutilon theophrasti Medicus (velvetleaf), at populations from 130 to 204 plants m 2 , has been shown to reduce soybean yields by 23% [9].…”