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Warren C Stiles and Michael Rutzke

A total of 3850 leaf samples from commercial apple orchards located throughout New York State were submitted for analysis during the 1989-1992 seasons. These included 2583 samples from mature, 968 from young bearing age, and 299 from young nonbearing orchards. Percentages of samples (all ages and all varieties combined) found to be below currently recommended levels were: Zn 75%, Cu 74%, B 68%, Ca 63%, K 60%, Mg 60%, Mn 38%, Fe 19%, N 15%, and P 8%. Percentages of samples found to be above currently recommended levels were: N 21%: Zn 16%, Mn 13%, K 6%, B 4%, Mg 2%, Cu <1 %, and P <l %. Major problems consist of shortages of Zn, Cu, B, Ca, K, and Mg in 60% or more of all samples analyzed. Seasonal, varietal, pest management program, and tree age effects were apparent in the results, indicating that these factors must be considered in interpreting results of leaf sample analyses into recommendations for fertilization programs.