Effect of Soil Type and Liming Rates on Rotational Forage Crop Injury Following Metsulfuron Methyl

Abstract

Solution pH from 6.0 to 8.0 did not affect the germination of Italian ryegrass, ‘Pensacola bahiagrass,’ or common bermudagrass grown in petri dishes in growth chambers. Seeding intervals following metsulfuron methyl application varied from species to species and between soil types. Greenhouse studies indicated that in an Okolona silty clay, common bermudagrass should not be planted until 12 wk after metsulfuron methyl application. Italian ryegrass showed no metsulfuron methyl injury at the 6-wk sampling date when no lime was added, indicating reseeding was feasible at this time; however, a 12-wk time interval was not sufficient when lime was applied. Pensacola bahiagrass was injured when reseeded at 12 wk, regardless of liming rate. In a Prentiss fine sandy loam soil, common bermudagrass could be reseeded 12 wk after application when no lime was added, but not when lime was added. Italian ryegrass and Pensacola bahiagrass should not be reseeded for at least 12 wk, regardless of lime rate. Field experiments, where metsulfuron methyl was applied to the field and seeding was carried out in the greenhouse, indicated on the Okolona silty clay that common bermudagrass reseeding could occur at all liming rates after 3 wk, and Italian ryegrass and Pensacola bahiagrass after 6 wk. In the Prentiss fine sandy loam, common bermudagrass reseeding could occur at 3 wk, regardless of lime rate. Italian ryegrass emergence was not affected when reseeded immediately after metsulfuron methyl application, but height was reduced for longer periods, and increased lime rate lengthened this interval. Pensacola bahiagrass reseeding was feasible at 3 wk.