Formation of double herbicide resistant oilseed rape plants under controlled conditions

When growing transgenic herbicide resistant crops side by side at the same time the formation of double herbicide resistant plants is considered as a possible problem for the management of volunteer crops. Particularly during the simultaneous cultivation of glufosinate-ammonium and glyphosate resistant crops management problems with volunteer crops are expected, as both complementary herbicides can not be used any more. To estimate the number of double herbicide resistant winter oilseed rape plants formed under optimal and controlled conditions, experiments were carried out in the vegetation periods 1999/2000 and 2000/2001 with the varieties Liberator LL C/6Ac (LL-rape) and Lirajet RR GT73 (RR-rape). For that, one plant each of both varieties were cultivated together in a 10-L-pot and put under an isolation bag at flowering. Alternatively, single plants were grown individually in pots and arranged like a chessboard side by side. Hand crossings were used as a control. The experiments were carried out in an open S1-vegetation green house.