Field tests with Madex Plus against CpGV-resistant codling moth populations in organic orchards in 2006

Summary in the original language of the document

When resistance to the Mexican isolate of Cydia pomonella Granulovirus (CpGV-M) arose
in several organic orchards in Germany in 2004 and 2005, the future of codling moth
control became a serious concern of organic fruit growing. In 2006, a new virus isolate
from Andermatt Biocontrol AG (Madex Plus) was first tested in two field trials in organic
orchards on codling moth populations resistant against the Mexican isolate of CpGV.
Madex Plus showed a better efficacy on these populations than Madex 3. However, larval
mortality larvae seemed to be somewhat delayed. A very good effect was shown in
population control. The number of larvae in corrugated card board belts was significantly
reduced after treatment with Madex Plus. In addition to these trials, on-farm trials in all
orchards concerned of the CpGV-M resistance were carried out. The results of on-farm
trials showed the same tendency: high efficacy in population control against a background
of slightly delayed larval death. In 2007, Madex Plus was applied successfully in all
organic orchards with CpGV-M-resistant codling moth populations in Germany.