Abstract
Calcium plays an important role in the growth and development of apple trees as well as in high fruit quality. In the present study, solution cultures were carried out under climatically controlled conditions in a growth room to evaluate the response of apple seedlings to six levels of Ca (0.1, 0.2, 0.4, 0.8, 1.6, and 3.2 mM Ca). Foliar calcium deficiency symptoms were observed at Ca concentrations lower than 0.4 mM. The 3.2 mM Ca treatment resulted in the highest shoot dry matter accumulation and the greatest leaf area. However, both root length and dry matter accumulation were less affected by Ca levels. Calcium uptake parameters were significantly influenced by Ca treatment.