Indirect means of weed control against Rumex spec. on arable fields and grassland in organic farming

In organic farming dock species, in particular Rumex crispus and R. obstusifolius, are very common and noxious weeds on arable fields and in grassland. In this paper results are presented on generative and vegetative reproduction of dock. In germination tests germinability of seeds was assessed that had been harvested in weekly intervals from mid May to end of June. Germination tests showed that germinability of seeds was very low at the time of hay making. However, with further ripening of plants germinability increased up to values over 80 % in germination tests using temperature shifts and light during the germination test. A second experiment was carried out in an arable field. Shoot and roots were partially removed and damage of the plants was assessed six weeks later. Vegetative growth was reduced, the more biomass was removed. Removing the entire shoot and part of the root by using a 'dock-stick' resulted in a very good control. Results of the two experiments show that there are efficient non chemical control methods available to minimize vegetative and generative reproduction of dock. Therefore, the question is discussed why docks arc considered such a problematic weed in organic farming.