Herbicide tests in lemon balm (Melissa officinalis L.) in Thuringia

Between 1996 and 2008 19 experiments with 33 herbicides were carried out in lemon balm in experimental stations and on lemon balm fields of Thuringian farms. The main objective of the tests was to get the necessary data for the authorization procedure according to the regulations of A aEuro-18a PflSchG. Lemon balm plants are very susceptible against some herbicides like Bacara, Bandur, Centium 36aEuro-CS, Goltix 700aEuro-SC, Husar, Sumimax. Other herbicides like Boxer, StompaEuro-SC and other Pendimethalin-herbicides can cause severe damages on peppermint if they are applied to the false stage of development of the plant and/or unfavourable climatic conditions. The use oft the herbicides Basagran, Boxer, Fusilade MAX, Lentagran WP and Stomp SC, Stomp Aqua, Stomp Raps is authorized for the application in lemon balm according the regulations of A aEuro-18a PflSchG. The herbicides Goltix 700aEuro-SC, LontrelaEuro-100 und CLIOPHARaEuro-100, Roundup UltraMAX and Targa Super can be used in lemon balm according the regulations of A aEuro-18b PflSchG. Further experiments with herbicides in lemon balm are intended to the authorization to more herbicides and to unsolved problems with the weed control in this crop like for example the often insufficient effects of the recently authorized herbicides against Solanum spec., Galinsoga spec., Polygonum spec. and other weeds.