Submitted to: North Central Weed Science Society US Proceedings
Publication Type: Proceedings
Publication Acceptance Date: December 13, 1994
Publication Date: N/A
Technical Abstract: Field research was conducted at Rosemount, MN, in 1994 to determine the effect of tillage in the dark on the emergence of 13 annual weed species under uniform soil and environmental conditions. The experiment was conducted in a weed nursery with 13 annual weed species grown individually in 5-m-wide strips. Tillage was conducted with a tandem disk operated 8 cm deep. Treatments included: two passes with the disk in the light, one pass in the light followed by the second pass in the dark, two passes in the dark, and no secondary tillage with glyphosate to control emerged weeds. Emergence of the annual grass species (barnyardgrass, green foxtail, giant foxtail, and yellow foxtail) was not affected by secondary tillage methods. Emergence of large-seeded broadleaf species (common cocklebur, giant ragweed, and velvetleaf) was similar following tillage in the light or dark. However, total emergence of the large-seeded species was less when glyphosate replaced secondary tillage. Emergence of small-seeded broadleaf species (common lambsquarters, common ragweed, eastern black nightshade, pigweed species, Pennsylvania smartweed, and wild mustard) was affected by the time of secondary tillage. Reduction in emergence when tillage was conducted in the dark varied by species and date of tillage. Compared to secondary tillage in the light, tillage in the dark reduced Pennsylvania smartweed emergence by 80% following tillage on May 12. Emergence reduction with other small-seeded species ranged from 30 to 70%. Based on the results of this experiment conducted at a single site for only one year, it appears tillage in the dark may have potential as a component of integrated weed management.