Establishment and Lateral Growth of Glyphosate-resistant Creeping Bentgrass in Bare Soil

Abstract

Plant establishment and lateral growth of glyphosate-resistant creeping bentgrass [Agrostis stolonifera (synonym A. palustris)] were assessed to determine if the insertion of the construct conferring herbicide tolerance affected establishment rate or aggressiveness characteristics in unmowed situations. Field studies were carried out in Michigan, Illinois, Ohio, and Oregon in 2000 and 2001 to examine the relative lateral growth of several transformed lines of creeping bentgrass, non-transformed controls, and cultivar standards. Vegetative plugs of creeping bentgrass were transplanted into replicated bare-soil plots and irrigated as needed to prevent moisture stress for an initial 6-week period. Measurements of maximum and minimum stolon spread, percent cover, and stand density for each entry were made in the field at all locations during 2000 and 2001. Few statistical differences (P = 0.05) in establishment and lateral growth were observed between individual lines of transgenic creeping bentgrass, non-transformed control lines, and standard cultivars and over a 15- to 18-month period. Overall, lateral growth and establishment rate of transgenic lines were similar to their non-transformed parent and the standard cultivars tested. Transgenic creeping bentgrass lines should have no greater potential for lateral growth than conventional creeping bentgrass cultivars currently in use.