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Integrated Weed Management for Foxtail Barley in Reduced Tillage
Author: R. E. Blackshaw, G. I. Semach, Xiangju Li, J. T. O'Donovan., and K. N. Harker
Date Created: February 11, 1999
Last Reviewed: January 26, 2009
Document Source: Weed Technology, Volume 13: 347 - 353.  Summary A four-year field experiment was conducted to determine the merits of combining cultural and chemical control to manage foxtail barley in reduced tillage systems. Factors studied were crop row spacing, seeding rate, application rate and timing of glyphosate within a spring wheat-flax cropping sequence: - Glyphosate applied pre-seeding at 400 and 800 g/ha killed foxtail barley seedlings but only suppressed established perennial plants. - Glyphosate applied post-harvest at 800 g/ha killed 60 - 70% of the established plants. - Combination of pre-seeding and post-harvest glyphosate gave the greatest reduction in foxtail barley biomass and seed production, and resulted in greatest increases in crop yield. - Including flax in a rotation allows the use of grass herbicides such as quazilofop or sethoxydim that effectively controlled foxtail barley seedlings and provided some suppression of perennial plants. - An increase in wheat seeding rate from 75 to 115 kg/ha reduced foxtail barley growth and increased wheat yield in 3 of 4 years. - Increasing the flax seeding rate from 40 to 80 kg/ha or reducing the wheat or flax row spacing from 30 to 20 cm provided little benefit in managing foxtail barley or increasing crop yield. A multi-year approach combining agronomic practices and timely use of herbicides should allow growers to effectively manage foxtail barley in annual cropping systems using reduced tillage.