美国加利福尼亚州及其他柑桔产区对柑桔果树的栽植密度已引起重视。由于采果的成本很高,劳力缺少,地价及税收的增多,柑桔生产者正在寻求更经济有效的栽培措施。栽植密度的研究已证明:密植可以提高单位面积的产量,特别是柑桔幼年树。本文报导九年生华盛顿脐橙的栽植密度对根系分布的影响。 The planting density of citrus fruit trees in California and other citrus growing areas in the United States has drawn great attention. Due to the high costs of picking up fruit, lack of labor, land premiums and taxes, citrus producers are seeking more cost-effective cultivation measures. Studies of planting density have demonstrated that close planting can increase yield per unit area, especially for juvenile citrus trees. This article reports the effect of planting density of nine-year-old Washington Navel orange on root distribution.