Tropentag, October 7 - 9, 2008 in Hohenheim "Competition for Resources in a Changing World: New Drive for Rural Development"

Evaluation of the Effects of Fallow–Forage Barley and Sugarbeet–Forage Barley Rotations on Density and Distribution of Weeds

Ferdowsi University of Mashhad, Department of Agronomy, Iran

Abstract

In order to evaluate of conventional management of fallow-forage barley and sugar beet-forage barley rotations and its effect on density and distribution of different species of weeds, this study was performed in two of barley fields, in Agricultural College of Ferdowsi University of Mashhad Experimental Station in 2003. Sampling was done by systematic method in which samples were taken from the corners of 7m*7m grids using 0.5m*0.5m size quadrates in three stages (pre application herbicide, post application of herbicide and pre harvesting). The results indicted that the density of annual weed seedlings in sugar beet- barley rotation was more than fallow- barley rotation, and the density of perennial weed seedlings in fallow- barley rotation was more than sugar beet- barley rotation. Map of species distribution and density confirmed patchiness distribution of the weeds. The shape and size of patches differed based on field and weed species, but spatial distribution did not change considerably before and after application of herbicide. Percentage of free weeds area was 11.5% and 1.5% in fallow- barley rotation and 0.6% and 0% in sugar beet- barley rotation in first and second sampling stage respectively. These results indicate inefficacy of sugar beet The besides more stress on weed infestation in sugar beet- barley rotation, in addition to more emphasis on weed infestation compare to sugar beet-forage barley rotation. Apparently, the evaluation of management conducted and paying special attention, to weed dispersal within the field, is able in implementation of appropriate management strategy, which includes high efficacy and profit for farmer as well as least damage to crops.

Keywords: Forage barley, patchiness distribution, site specific management, weed management, crop rotation

Contact Address: Asieh Siah-Marguee, Ferdowsi University of Mashhad, Department of Agronomy, Azadi Square, 91775-1163 Mashhad, Iran, e-mail: siahmargueyahoo.com