Abstract
Changes in fertilizer and pesticide formulations plus success in reducing sulfur (S) emissions to the air from industrial operations have reduced the availability of S to peach trees in some locations. Peach (Prunus persica L. Batsch) trees on highly leached acid sands have shown responses to S fertilization. The levels of total S required for S sufficiency is important to determine fertilizer needs. The 100 ppm SO4‐S requirement offered by some sources has been misinterpreted. Greenhouse experiments with Nemaguard, Lovell, Montclar and Nemared rootstock seedlings resulted in the establishment of levels representing S deficiency and sufficiency. The foliage and growth rates of rootstock seedlings in this experiment showed severe deficiency symptoms at 550–990 μg S g‐1 DW. Sufficiency was achieved at 1400–2500 μg S g‐1 DW.