Sod Harvesting Intervals of Four Warm-Season Turfgrasses After Halosulfuron and Sulfentrazone Applications.

Sedges are problematic weeds that reduce quality of turfgrass sod and herbicides may be needed for control prior to harvesting.  The objective of this research was to evaluate application timing of sulfentrazone on sod quality, tensile strength, and post-harvest rooting of four warm-season turfgrasses.  Bermudagrass (Cynodon dactylon x C. transvaalensis Burtt-Davy) injury from herbicides was minimal (<10%) but injury to centipedegrass (Eremochloa ophiuroides (Munro) Hack.), St. Augustinegrass (Stenotaphrum secundatum (Walter) Kuntze), and zoysiagrass (Zoysia matrella (L.) Merr.) was detected before harvesting and generally increased with sulfentrazone rate from 0.21 to 0.84 kg ai ha^-1.  Sod tensile strength was not reduced from the untreated for bermudagrass and centipedegrass treated with herbicides but measurements were reduced 15% and 22% following herbicide applications 1 week before harvesting (WBH) St. Augustinegrass and zoysiagrass, respectively.  Sulfentrazone at 0.84 kg ha^-1 reduced zoysiagrass tensile strength 20% from the untreated but other treatments did not reduce measurements.  Turf injury from halosulfuron was negligible and treatments did not affect sod tensile strength of the four species.  Treatments did not affect root mass of any species at 4 weeks after sod transplanting.  Sod quality after transplanting was reduced from the untreated on several dates for centipedegrass and St. Augustinegrass when treated with sulfentrazone 1 and 2 WBH while zoysiagrass quality was reduced from treatments 4 WBH.  Bermudagrass quality after transplanting was not reduced from the untreated by any herbicides.  Results suggest sod harvesting should be delayed >2, >2, and ≥4 weeks after sulfentrazone applications at labeled rates for centipedegrass, St. Augustinegrass, and zoysiagrass, respectively, while bermudagrass sod can be safely harvested 1 WAT.  Sod harvesting should be delayed 1, 2, ≥4, and 2 wk after halosulfuron treatments at 0.07 kg ha^-1 for bermudagrass, centipedegrass, St. Augustinegrass, and zoysiagrass, respectively.