Methiozolin [5-(2,6-difluorobenzyl)oxymethyl-5-methyl-3,3(3-methylthiophen-2-yl)~(~(-1)) ,2-isoxazoline], a new annual bluegrass (Poa annua L.) herbicide for turf grasses

摘要

BACKGROUND: Selective control of annual bluegrass {Poa annual L.) has been difficult in turf grasses. The potential of methiozolin in this area was investigated. RESULTS: Methiozolin was safe on established zoysiagrass (Zoysia japonica Steud.), creeping bentgrass {Agrostis palustris Huds.), Kentucky bluegrass [Poa pratensis L), and perennial ryegrass (Lolium perenne L.) at 1000 g ha~(-1), and controlled annual bluegrass with GR_(50) values of 23,52,104, and 218 g ha~(-1) at PRE, two-, four- and eight-leaf stage, respectively, in the greenhouse. When applied at early flowering, methiozolin suppressed >80% of annual bluegrass seed heads at 2000 g ha~(-1).~(14)C-Methiozolin was readily absorbed by both leaves and roots, but translocation was mainly acropetal. No herbicidal activity resulted from application to the leaf only; however, application to the soil surface only showed equivalent herbicidal activity to that of broadcast application to the leaf and soil. Methiozolin at S00 to 1000 g ha~(-1) provided 80 to 100% control of annual bluegrass when applied in the fall with acceptable and temporary injury to creeping bentgrass, and about 60% control when applied in the spring with no bentgrass injury in the field. CONCLUSION: Methiozolin is an excellent candidate for annual bluegrass management in turfgrasses.