FUSILADE 4E, fluazifop-butyl, was introduced in 1982 for perennial and annual grass control in cotton. Fluazifop-butyl contains an asymetric carbon atom normally existing as two optically active enantimomers, R and S. Research conducted by ICI at Jealott's Hill, England, has shown the R enantiomer to be herbicidally active against Gramineae and the S enantiomer to have very little herbicidal activity. FUSILADE 2000 (IE), fluazifop-P-butyl, contains only the active R enantiomer and will be phased into the cotton market in 1986.

The objective of this report is to show the herbicidal relationship of FUSILADE 2000 to FUSILADE 4E on perennial grasses in cotton with composite results of trial conducted throughout the Mississippi Delta and Texas. Results from trials conducted by ICI Technical Representatives on johnsongrass and bermudagrass across the region were compiled. In addition, summaries included data from university trials across the same region (see acknowledgements).