Experiments were conducted on the use of granular fenuron, 25% active, for white pine release and establishment. The effect of fenuron on the plant community was also investigated. Studies included in the white pine release experiment were the effect of season of treatment on the kill of hardwoods and percentage survival of indigenous white pine, and the effectiveness of fenuron on various species of hardwoods. All hardwood stems over six feet tall were treated with four grams of active fenuron placed on the soil at the base of the tree. Treatments were made in May 1960, August 1960, and March 1961. The May treatment was most effective in the removal of the hardwoods. There was a reduction of 59% of pines over six feet tall and an increase of 45% of pines less than six feet tall. Red maple and the oaks were the species most susceptible to the treatment; whereas, chestnut, sassafras, and black locust were the least susceptible. In the white pine establishment experiment, the residual effect of fenuron on white pine seedlings, and its effectiveness at a lower rate on various hardwoods were lnvestigated. Each hardwood stem over six feet tall was treated with one gram active fenuron in the spring of 1960. In March 1961, 100 white pine seedlings were planted in each of three plots previously treated. Five months after planting there was 99% survival of the pine seedlings. The one-gram rate was effective against red maple and the oaks but had little effect on sassafras, cucumber tree, and chestnut. Fenuron in some manner changed the composition of the plant community. Fireweed, poke, and several species of Panicum were present in the treated plots but were not present in the untreated buffer strips. / Master of Science