A new, prepackaged mixture of saflufenacil dimethenamid-P has been introduced for PRE control of grass and broadleaf weeds in corn. Field experiments with this new herbicide combination were conducted in 2008 and 2009 at four locations in southern Ontario, Canada. The objective of this study was to determine the dose of saflufenacil dimethenamid-P required for overall weed control and species-specific weed control, as well as the dose required for early season weed control when followed with glyphosate at the six- to eight-leaf corn stage. Based on weed dry weight, the GR95 across locations ranged from 126 to 675 g ha−1. The 95% growth reduction (GR95) for common ragweed, common lambsquarters, pigweed, and wild mustard were 933, 325, 186, and 115 g ha−1, respectively. Highest corn yields were achieved with saflufenacil dimethenamid-P applied alone at doses ranging from 368 to 1470 g ha−1. When followed by glyphosate, the dose range of saflufenacil dimethenamid-P required to achieve the greatest corn yields was 46 to 1,470 g ha−1. A minimum dose of 184 g ha−1 of saflufenacil dimethenamid-P followed by glyphosate was required for the yield to exceed that of the single treatment of glyphosate applied alone.
Nomenclature: Dimethenamid-P; glyphosate; saflufenacil; common lambsquarters, Chenopodium album L. CHEAL; common ragweed, Ambrosia artemisiifolia L. AMBEL; pigweed species, Amaranthus spp. AMASS; wild mustard, Sinapis arvensis L. SINAR; corn, Zea mays L.