Abstract
Organic apple production is of increasing commercial importance throughout Europe, but especially in South Tyrol where about 25% of the whole European organic apple crop is produced. In organic apple production, producers face the challenge of choosing varieties that are both in demand and also resistant to the main pests and diseases. Every now and then, the question arises, if yields, losses and profitability are different in integrated and organic orchards and in how great are the differences between single apple varieties. In 1999 the Laimburg Research Centre started a field trial to observe the effects of different cultivation methods on 18 apple varieties in a randomised block design. In the first four years of production, significant differences in the yield potential between the varieties as well as between integrated and organic production were observed. In organic farming, yields were lower and organic fruits were of smaller size. In organic production the leaves contained less nitrogen in spring. In summer there were no more significant differences concerning nitrogen.