Alleyway groundcover management and scab resistant apple varieties

Summary

The use of scab resistant apple varieties is the best way to prevent infections of apple scab (Venturia inaequalis). In 1995 the then 10 most promising resistant apple varieties for Denmark where planted at Research Centre Årslev, Denmark in an organic production system. Three different covercrops where established in the alleyways. Weed cleaning in the tree row was done mechanically and the trees were kept unfertilised.
The annual shoot growth, nutrients in leaf sample, mineralised nitrogen in soil, content of water in the upper 50 cm soil, fruit yield and fruit quality were assessed.
The annual covercrop caused the longest shoot growth, the highest content of nitrogen in leaves and soil, the smallest competition with the trees concerning soil water and the highest gross yield of the lowest quality. The resistance to apple scab was broken down in most varieties.