Home » Row width and plant population effects on glyphosate-resistant sugarbeet production in Michigan. by Jon-Joseph Quincy Armstrong
Row width and plant population effects on glyphosate-resistant sugarbeet production in Michigan. Jon-Joseph Quincy Armstrong

Row width and plant population effects on glyphosate-resistant sugarbeet production in Michigan.

Jon-Joseph Quincy Armstrong

Published
ISBN : 9781109237801
NOOKstudy eTextbook
91 pages
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 About the Book 

The 2008 commercial release of glyphosate-resistant (GR) sugarbeet provided growers with the opportunity to achieve excellent control of many weed species common to sugarbeet production with fewer herbicide active ingredients and fewer applications,MoreThe 2008 commercial release of glyphosate-resistant (GR) sugarbeet provided growers with the opportunity to achieve excellent control of many weed species common to sugarbeet production with fewer herbicide active ingredients and fewer applications, white eliminating the potential for crop injury. GR sugarbeet may allow growers to reduce or potentially eliminate between-row cultivation and adopt planting in narrow rows. Field trials were conducted in 2006, 2007, and 2008 at multiple locations in Michigan to compare canopy cover, yield and quality, and weed control in GR sugarbeet planted in 38-, 51-, and 76-cm rows widths at plant populations of 54,000- 78,000- 101,000- and 124,000 plants/ha. In general, canopy cover developed more rapidly and was greater in 38- and 51-cm row widths and at higher plant populations. At the Saginaw Valley locations, GR sugarbeet planted in 51-cm rows produced the highest root yields. At the East Lansing location, root yields were highest in 38-cm rows compared with 76-cm rows in 2008. Sugarbeet quality, expressed as recoverable white sucrose per Mg of root (RWSMg), also increased as plant population increased.-Weed control in GR sugarbeet is affected by row width. Weed population densities and biomass were lower in narrow rows compared with 76-cm rows following a single glyphosate application when weeds were 10-cm tall. The greater canopy cover provided by narrow rows may reduce the number of glyphosate applications necessary for season-long weed control. When averaged over row width, GR sugarbeet root yield was similar to yield of the weed-free treatment for all herbicide treatments where glyphosate was applied when weeds were 10-cm in height or smaller. However, root yields were reduced when glyphosate applications were delayed until weeds averaged 15-cm in height. Regardless of row width, initial glyphosate applications should be made before weeds reach 10-cm in height to maximize yield and minimize weed competition.-The increased cost of GR sugarbeet seed may influence adoption of narrow row sugarbeet production. At the Saginaw Valley locations, GR sugarbeet planted in 51-cm rows had an increase in gross margin of at least {dollar}200/ha compared with 38- and 76-cm rows, when payment price was adjusted for sugarbeet quality. At East Lansing, gross margins did not differ among all row widths and plant populations in 2007. In 2008, plant populations of 78,000- 101,000- and 124,000 plants/ha in 38-cm rows resulted in the highest gross margins. Despite observed increases in RWSMg at higher plant populations, results from this analysis suggest that row width has more of an impact on economic returns for GR sugarbeet production. The highest economic returns were for sugarbeet planted in narrow rows.-Additional herbicides may be necessary for satisfactory control of weeds that are more tolerant to glyphosate. In greenhouse trials, triflusulfuron was not effective for control of 5- or 10-cm tall velvetleaf, Powell amaranth, or common lambsquarters. Some combinations of glyphosate plus triflusulfuron were synergistic for weed control. All combinations of glyphosate and triflusulfuron were additive for control of common lambsquarters. However, triflusulfuron plus glyphosate applied to 5- and 10-cm weeds did not improve weed control beyond using glyphosate alone at 840 g/ha.