Calcium Soucers for apple production in Paraná, Brazil

ABSTRACT

The effects of six calcium sources (dolomitic lime, calcitic lime, hydrated lime, silicated lime, calcium sufate (phosphogypsum) and calcium chloride) on the production of mature apple trees were evaluated in a field experiment. The soil was an inceptisol with low pH and Ca, and high Al contents in both top and subsoil. Fruit yields increased with dolomite, silicate, calcite and sulfate calcium sources. Hydrated lime had no effect and calcium chloride reduced yields. Positive residual effects were obtained with dolomite, calcite, silicate and phosphogypsum treatments. A very close negative relationship was found between yields and the concentration of exchange-able Al for all sources, except for the phosphogypsum treatment.