| Abstract/Contents: | "Three studies (Midlawn, Tifway and El Toro) were conducted at Lonoke, AR and one study (Midlawn) at Stillwater, OK during 1995 to evaluate herbicides for sprigging. Planting at Lonoke was done on June 23, 1995. The sprigging rate at both locations was 600 bu/a. Sprigs were spread by hand, lightly disked, and then rolled. Preemergence herbicides were applied immediately after sprigging and one-half inch of irrigation was applied immediately following herbicide application. MSMA treatments were applied on July 13, 1995. Plots were 6 ft by 15 arranged in a randomized block with four replications. Herbicide use rates in lb ai/a were oxadiazon 2.0, MSMA 2.0, oryzalin 1.5, pendimethalin 1.5, dithiopyr 0.5, simazine 1.0 and prodiamine 0.75. Additional treatements included oxadiazon, oryzalin, pendimethalin, dithiopyr and prodiamine tank mixed with simazine using the rates listed above. In the El Toro study, siduron at 4.0 lb ai/a was substituted for oryzalin. In the Arkansas study, At 28 DAT, the percent Midlawn bermudagrass cover rankings were oxadiazon 55%, untreated 45%, MSMA 40%, oryzalin 31%, pendimethalin 25%, dithiopyr 16%, simazine 13% and prodiamine 9%. Percent cover for the simazine tank mixes were oxadiazon 6%, oryzalin 9%, pendimethalin 6%, dithiopyr 5%, and prodiamine 5%. At 66 DAT, the percent Midlawn bermudagrass cover rankings were oxadiazon 99%, MSMA 90%, oryzalin 80%, untreated 75%, dithiopyr 75%, pendimethalin 73%, prodiamine 68% and simazine 58%. Percent cover values for the simazine tank mixes were oxadiazon 68%, oryzalin 65%, dithiopyr 60%, pendimethalin 55%, and prodiamine 48%. At 72 DAT, percent cover rankings for Midlawn planted August 14, 1995 and sprayed August 16, 1995 at Stillwater OK, were simazine 54%, untreated 49%, prodiamine 21%, pendimethalin 18%, oryzalin 15%, dithiopyr 14%, and oxadiazon 13%. Percent cover for the simazine tank mixes was <5%. At 28 DAT, the percent Tifway bermudagrass cover rankings were untreated 50%, MSMA 45%, oxadiazon 38%, simazine 33%, oryzalin 29%, pendimethaline 28%, prodiamine 28%, and dithiopyr 18%. Percent cover for the simazine tank maxes were pendimethalin 35%, dithiopyr 30%, oxadiazon 28%, oryzalin 25%, and prodiamine 25%. At 66 DAT, the percent Tifway bermudagrass cover rankings were MSMA 99%, oxadiazon 97%, untreated 90%, prodiamine 90%, pendimethalin 87%, oryzalin 80%, dithiopyr 80%, and simazine 80%. Percent cover values for the simazine tank mixes were dithiopyr 97%, pendimethalin 95%, oxadiazon 90%, oryzalin 90%, and prodiamine 85%. At 66 DAT, the percent cover rankings for El Toro zoysiagrass were oxadiazon 73%, siduron 60%, MSMA 58%, simazine 53%, pendimethalin 50%, dithiopyr 48%, untreated 23%, and prodiamine 18%. Percent cover values for the simazine tank mixes were oxadiazon 85%, siduron 80%, dithiopyr 63%, prodiamine 35%, and pendimethalin 23%. Large crabgrass (Digitaria sanguinalis) control ratings were collected at Lonoke. The most effective crabgrass herbicides across all three studies were oxadiazon, dithiopyr, and prodiamine all providing >90% control at 28 DAT. At 66 DAT, only the prodiamine + simazine, oxadiazon and MSMA treatements in the Midlawn study were providing >80% control." |
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