Absorption and Translocation of Foramsulfuron in Dallisgrass (Paspalum dilatatum) Following Preapplication of MSMA

Abstract

Several field studies have observed increased foramsulfuron efficacy for the control of dallisgrass when foramsulfuron is applied after MSMA. Therefore, laboratory studies were conducted with mature dallisgrass to study the absorption and translocation of 14C-foramsulfuron, and then examine the impact of preliminary applications (preapplications) of MSMA or foramsulfuron on herbicide absorption and movement. Herbicide absorption increased rapidly through 4 h, and by 8 h, differences in absorption between pretreated and control plants were evident. After 48 h, foramsulfuron absorption in non-pretreated plants was 55%, whereas plants that received either pretreatment absorbed 70% of the herbicide. Translocation above (younger tissue) and below (older tissue) the treated leaf was 0.65 and 0.62% for non-pretreated plants, respectively. Pretreatment with foramsulfuron resulted in the translocation of 2.12 and 1.55% of applied radioactivity above and below the treated leaf, respectively. Pretreatment with MSMA resulted in the translocation of 2.33 and 2.34% of applied radioactivity above and below the treated leaf, respectively. These data indicated that pretreatment of mature dallisgrass with either foramsulfuron or MSMA results in an increase in both uptake and translocation of foramsulfuron applied 2 wk after pretreatment. The increase in absorption and translocation of foramsulfuron in the pre–MSMA-treated plants may explain the increase in control observed in the field when comparing it to the pre–foramsulfuron-treated dallisgrass plants.

Efficacy of Flazasulfuron for Control of Annual Bluegrass (Poa annua) and Perennial Ryegrass (Lolium perenne) as Influenced by Nitrogen

“…herein, and a nonionic surfactant was not included in the radioactive solution used in that study. Absorption values for other SU herbicides applied to various grasses have been shown to be greater than those reported by Willis (2008) but less than those reported in this laboratory experiment (Williams et al 2003;Henry et al 2008;King et al 2003;Gallaher et al 1999).…”

“…Translocation experiments were arranged in a split-split plot design with three replications, similar to the design used by Henry et al (2008) to evaluate the effects of pretreatment with MSMA on the translocation of foramsulfuron applied to dallisgrass. In this laboratory experiment, HAT (1,4,8,24,48, and 72 h) served as the whole plot treatment, N fertility (0 kg N ha 21 or 73 kg N ha 21 ) served as subplot treatment, and plant part (treated leaf, shoot tissue, root tissue) served as the sub-subplot treatment.…”

“…Laboratory studies evaluating absorption and translocation 14 C-labeled herbicides have been used to explain treatment responses in the field. Henry et al (2008) used 14 Cforamsulfuron to determine that increases in dallisgrass (Paspalum dilatatum Poir.) control with MSMA followed by foramsulfuron were due to increased translocation of foramsulfuron after MSMA application.…”

Dallisgrass (Paspalum dilatatum) Control with Thiencarbazone-methyl, Foramsulfuron, and Halosulfuron-methyl in Bermudagrass Turf

“…Chemical control options are currently limited for dallisgrass. One of the most common control programs is the use of sequential monosodium methanearsonate (MSMA) applications; however, this may present phytotoxicity concerns to warmseason turfgrasses (Henry et al, 2007b;Henry et al, 2008). Summer applications of MSMA have been reported to cause reductions in turf quality in both 'Tifway' hybrid bermudagrass (Cynodon dactylon • Cynodon transvaalensis Burtt-Davy) and common bermudagrass [C. dactylon (L.) Pers.]…”

“…In addition to a lack of efficacy for dallisgrass control when applied after early spring, it has also been well documented that fluazifop may cause phytotoxicity to bermudagrass turf (Bryson and Wills, 1985;Johnson, 1992;McElroy and Breeden, 2006;). Nonselectivity of glyphosate limits its use to spot spray applications that may cause nontarget damage to hybrid bermudagrass (Henry et al, 2008). The lack of noninjurious and effective herbicides for dallisgrass control warrants further investigation into chemical control options for use in warm-season turfgrasses.…”