Orchard soil management trials. 2. Effect of herbicides and nitrogen on growth and yield of young apple trees in permanent pasture

Abstract

On two cultivars of young apple trees growing in a permanent pasture, a narrow strip was kept bare with herbicide sprays used either during spring and summer or during the entire year. This increased tree growth, fruit set, fruit yield, and fruit size. Using more nitrogen fertilizer did not compensate for the grass competition and did not increase growth or yield as much as did the herbicide sprays. Most of the applied nitrogen could be accounted for in the increased growth of grass. The herbicide simazine increased tree growth more than other herbicides.