Fusilade (fluazifop-butyl), a selective postemergent herbicide for grass control, has gained widespread use in the landscape maintenance and nursery markets. Although the 1985 label for Fusilade 4E listed its use as being safe for over-the-top application to some 415 ornamental species and cultivars, foliar damage has been reported on some landscape ornamentals (1, 2, 3, 4, 5, 6).
A new formulation, Fusilade 2000 (fluazifop-P-butyl), has been released and will replace the familiar 4E formulation. Svenson et al. (7) evaluated phytotoxicity of Fusilade 2000 on 22 container-grown ornamental species. No or no significant injury occurred on most plants evaluated; however, Photinia × fraseri, Prunus cerasifera ‘Atropurpurea,‘ Prunus cistinea, and Spiraea × bumalda did show foliar distortion, chlorosis, and necrosis.
To expand the information on potential phytotoxicity, Fusilade 2000 was applied (over-the-top) at 0.25 and 1.0 lbs ai. per acre in 30 gallons water per acre to 16 field-grown woody ornamental species (Table 1) in a replicated study in June 1985. There was no evidence of foliar damage at either rate of Fusilade 2000 at two or four weeks after application. Most of the species initiated normal new growth during the evaluation period. Fusilade 2000 appeared safe for use on all species evaluated at the rates tested.
Field grown woody ornamentals evaluated for phytotoxicity (% leaf damage) of Fusilade 2000. No damage resulted from 0.25 or 1.0 lbs al/A either 2 or 4 weeks after application.
- Copyright © 1986, International Society of Arboriculture. All rights reserved.
Literature Cited
- ↵Ahrens, J. F. 1983. Postemergence grass herbicides for woody ornamentals and Christmas trees. Northeast Weed Sci. Soc. Proc. 37:318.
- ↵Bing, A. and M. Macksei. 1984. Postemergence applications of fluazifop-butyland sethoxydim on azaleas. Northeast Weed Sci. Soc. Proc. 38:128–130.
- ↵Frank, J. R. and C.E. Beste. 1983. Sethoxydim and fluazifop-butyl for weed control in field-grown azaleas. Northeast Weed Sci. Soc. Proc. 37:331 (abstr.).
- ↵Kuhns, L. J., G. Twerdok, and C. Haramaki. 1983. Screening woody ornamentals for tolerance to fluazifop-butyl and sethoxydim. Northeast Weed Sci. Soc. Proc. 37:254–255.
- ↵Rice, R. P., Jr., G. Lewis, and K. Harrell. 1985. Potential of fusilade, poast and CGA 82725 for control of weedy grasses in woody nursery crops and groundcovers. J. Env. Hort. 3(1):28–32.
- ↵Smith, E. M. and S. A. Treaster. 1985. Tolerance of landscape plants to fusilade and poast. Tenn. Nursery Digest 7(7):2.
- ↵Svenson, S. E., W. T. Witte and D. Crater. 1985. Phytotoxicity evaluation of PP05 experimental herbicide on 22 species of woody ornamentals HortScience 20(4):659 (abstr.).
