Control of Annual Grasses and Revegetation in Ponderosa Pine Woodlands

Application of 1.12 kg/ha of the herbicide atrazine sufficiently controlled medusahead or downy brome to permit establishment of perennial wheatgrass in ponderosa pine woodlands previously burned in wildfires. Fall application of atrazine greatly improved survival of ponderosa pine or bitterbrush seedlings transplanted to plots the following spring. Bitterbrush seedlings established naturally in areas treated with atrazine. Apparently the herbicide treatment created a desirable habitat for seed caching by rodents, along with reduction of competition from annual grasses. Higher rates of atrazine controlled most herbaceous vegetation and resulted in greater growth of ponderosa pine seedlings. Failure to establish perennial grasses resulted in reinvasion by annual grasses.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information.Migrated from OJS platform August 202