Response of Tall Fescue to R.P.-EXP31130A and R.P.-EXP31598A

Abstract

EXP31130A and EXP31598A were applied as repeat applications on June 5 and July 23, 1997 to tall fescue turf maintained at 3.0 inches. Application rates were 0.18 and 0.36 lbs. AI/A (31130A) and 7.0 and 14.0 fl. oz/prod/A (31598A). Each treatment was applied with and without Sequestrene 338 iron chelate, at the rate of 0.1 oz/m ². Untreated and iron-only controls were included in the test. Neither herbicide compound (either with of without iron) caused discoloration, leaf tip burn, sheath necrosis, or blotchy colored turf at the rates and timing applications performed here for low maintenance tall fescue under desert summer conditions. EXP31598A herbicide, when applied without iron to tall fescue turf, exhibited acceptable levels of turfgrass color at all times when applied at the 7 ounce/prod./acre rate. EXP31598A herbicide, when applied without iron to tall fescue turf, exhibited a lighter, but acceptable color turf, when applied at the 14 ounce/prod./acre rate. When iron was added, the 14 ounce/prod./acre rate of EXP31598A produced in general, a slightly darker turf than the same compound at the 7.0 ounce/prod./acre rate. Improved turf color resulted from the addition of iron at 0.1 ounce/m ² for tall fescue treated with EXP31130A. This occurred more so for turf treated at the low rate (0.18 lb. AI/A) than for turf treated at the high rate (0.36 lb. AI/A). The addition of iron to EXP31130A did not increase overall quality at either application rate of the herbicide. When iron was added (0.1 ounce/m ²), turfgrass quality was improved for EXP31598A, especially at the high application rate of 14 ounce/prod./acre.