Eight years of experience with the apple rootstock M200

Abstract

For a period of 8 years, the M200 rootstock developed by the NIAB EMR centre (East Malling, UK) has been tested in a common trial between the Laimburg Research Center (Italy) and the Dienstleistungszentrum Ländlicher Raum Rheinpfalz in Klein-Altendorf (Germany). A positive aspect of the rootstock is its higher yield per tree compared to M9 T337 combined with a similar fruit quality. The smooth surface of the rootstock is almost free of burr knots. In contrast to M9 T337, root suckers are also very rare. M200 did not show more tolerance to replant disease than M9: Especially in the year of planting and in the second leaf, growth and yield deficits similar to M9 T337, G 11 and G 41 were found on untreated soil. M200, however, was significantly more vigorous than M9 T337 at the Laimburg Research Center, which can be an advantage in replant disease conditions or in combination with weak growing varieties. In Klein-Altendorf, M200 showed similar vigor to M9 T337, although it should be noted that the new rootstock achieved higher shoot growths than M9 T337 up to the forth year after planting. G 11 is less vigorous than M200 in both trials. This divergence confirms that in the evaluation of rootstocks the interactions between rootstock, soil, and climatic conditions must be considered.