Field experiments were conducted near Scottsbluff, NE, in 2001 and 2002 to compare economic aspects of glyphosate applied to different glyphosate-resistant sugar beet cultivars with that of conventional herbicide programs applied to near-equivalent, non–glyphosate-resistant conventional cultivars. Glyphosate applied two or three times at 2-wk intervals, beginning when weeds were 10 cm tall, provided excellent weed control, yield, and net economic return regardless of the glyphosate-resistant sugar beet cultivar. All conventional herbicide treatments resulted in similar net economic returns. Although the conventional sugar beet cultivars ‘HM 1640’ and ‘Beta 4546’ responded similarly to herbicide treatments with respect to sucrose content, ‘Beta 4546RR’ produced roots with 1% more sucrose than ‘HM 1640RR’. When averaged over herbicide treatments, a producer planting Beta 4546RR could afford to pay US $185/ha more for glyphosate-resistant technology as could a producer planting HM 1640RR. When averaged over cultivars and herbicide treatments, it is estimated that a producer could afford to pay an additional US $385/ha for glyphosate-resistant technology without decreasing net return.
Nomenclature: Glyphosate; sugar beet, Beta vulgaris (L.) ‘Beta 4546’, ‘Beta 4546RR’, ‘HM 1640’, ‘HM 1640RR’.
Additional index words: Herbicide-tolerant crops, technology fee, weed management, clopyralid, desmedipham, ethofumesate, phenmedipham, triflusulfuron.
Abbreviations: DES, desmedipham; fb, followed by; PHEN, phenmedipham; RG, gross return; TRIF, triflusulfuron; Y, root yield.