During perennial tree production, soil properties are constantly affected by the type, rate and method of application of soil and/or foliar amendments. These amendments are applied repeatedly over a number of years as a part of routine production practices. In the case of amendments containing mobile elements, the residual effect is negligible. However, application of amendments containing immobile elements results in accumulation of those elements in the topsoil. This is usually the case with respect to trace metals such as Cu, Zn, Fe and Mn which are essential for plant growth. In the event of extreme deficiencies of these elements, growth and production are adversely affected. However, in perennial tree crops such as citrus, the quantity of trace metals removed in harvested fruit is extremely small (Smith 1966). Therefore, repeated applications of these trace metals over the years result in their buildup in the topsoil. A case in point is the buildup of Cu in many citrus grove soils in the central ridge area of Florida as a result of routine application of Cu at relatively high rates with fertilizers (Alva and Graham 1991). Copper deficiency related citrus dieback symptoms were observed as early as the 1840's (Smith, 1966). Experimental evidence of Grossenbacker (1916) and Floyd (1917) indicated that application of copper sulfate corrected dieback symptoms, therefore, application of copper sulfate became a routine practice in Florida citrus production during the early 1900's. By the early 1940's, application of Cu in routine citrus fertilization program was often as high as 34 kg/ha. In addition, the routine fungicide spray program added 9 kg Cu/ha annually. Repeated application of Cu in the above doses resulted in buildup of Cu causing Cu toxicity (Reuther and Smith, 1954). In order to meet the fruit quality standards, production practices of groves destined to fresh fruit market require more pesticide spray programs as compared to the groves destined to produce fruit for juice processing. As a result, Cu contribution through pesticide