Published online by Cambridge University Press: 12 June 2017
Paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) was evaluated as a pretreatment for eastern redcedar (Juniperus virginiana L. # IUPVI) before spring burning in tallgrass prairie. Wetting sprays of paraquat at 0.3 g ai/L or 0.6 g/L were applied to crowns of small (0.8 to 1.5 m), medium (1.5 to 2.5 m), and large (2.5 to 5.0 m) eastern redcedar trees in August 1983 and 1984 before prescribed burns in the springs of 1984 and 1985. Paraquat alone at the 0.6 g/L concentration killed about 90% of the crown of small trees but as little as 30% of the crown of large trees. Paraquat pretreatments increased post-fire damage to small- and medium-size trees and partially compensated for light fine fuel loading.