Wild Oat (Avena fatua) Competition with Spring Wheat: Plant Density Effects

Abstract

Field experiments were conducted to measure the grain yield of wheat (Triticum aestivumL. ‘ANZA’) at various wild oat (Avena fatuaL. ♯ AVEFA) and wheat plant densities. Wheat yield declined as wild oat plant density increased. Wheat yield increased in wild oat-infested plots as wheat plant density increased. Regression models were developed to describe the combined effect of wheat and wild oat plant densities on wheat grain yield. Wheat yields were best described by a nonlinear regression model using the relative density of wild oat in the weed-crop stand as the dependent variable. Inclusion of crop stand as a competitive factor significantly improved the fit of all regression models tested. Wild oat were more competitive against wheat in these experiments than in experiments reported by others. Possible reasons for differences in observed competitiveness are discussed.

Competition, Morphology and Canopy Structure in Wheat (Triticum aestivum L.) and Wild Oat (Avena fatua L.) Exposed to Enhanced Ultraviolet-B Radiation

“…However, the competitive outcome between these two species may differ, depending on factors such as density (Carlson & Hill, 1985;Martin & Field, 1987), the relative timing of seedling emergence of crop and weed (Chancellor & Peters, 1974;O'Donovan et al, 1985), and soil nutrient levels (Henson & Jordan, 1982;Carlson & Hill, 1986). In any case, the emphasis of the present study concerns the influence of UV-B on competitive balance rather than the outcome of competition, per se.…”

Weed community composition after 43 years of long-term fertilization in tropical rice–rice system

“…Under different fertilization treatment, soil nutrient concentration varied significantly, which exerted great impact on the diversity and density of individual weeds species (Carlson and Hill, 1985). The influence of fertilization on weeds is Table 2 Analysis of covariance (test of between subject effects) of weed density and rice grain yield.…”

An analysis of polygenic herbicide resistance evolution and its management based on a population genetics approach

“…For example, inter-row cultivation and shallow cultivation before planting would reduce weed pressure on crops (Pannell et al 2004;Norsworthy et al 2012). Narrow row spacing and usage of highly competitive crop varieties might suppress weed growth due to increased competition from crop plants (Carlson & Hill 1985;Medd, Auld, Kemp, & Murison 1985;Norsworthy & Oliver 2001). Crop rotations would increase the opportunity for diversified herbicide usage and the integration of cultural methods (Johnson & Coble 1986;Cardina, Herms, & Doohan 2002).…”