Roundup Ready, a new weed control management in sugar beets First results of a field trial series in Germany

In 1998, a three-year nation-wide series of field trials with the system Roundup Ultra (genetically modified variety + herbicide Roundup Ultra) in sugar beets has been started. The genetically modified herbicide tolerant sugar beet variety is not yet licensed for cultivation in practice and is currently tested at the Federal Office of Plant Varieties on yield, quality and herbicide tolerance. The non-selective herbicide is registered in Germany since 1975, without permission for over the top application in sugar beets. The required field trials for the herbicide registration at the Federal Biological Research Centre for Agriculture and Forestry have already been finished with the season 1998. The aim of the trial series is to investigate the supposed advantages of the Roundup Ready system and its suitability for German agricultural systems. The program is based on a detailed protocol for herbicide testing. A broad range of implication timings and quantities of Roundup Ultra are tested on efficacy, on crop tolerance towards the herbicide, on sugar yield and quality comparison with recommended conventional weed control methods. Summarising the one year data package it can be emphasized that the revealed results were showing for both, the Roundup Ready system and conventional herbicides, sufficient weed control under various weed infestation levels all over Germany. Advantages of Roundup Ultra towards some weed species have been noticed, e. g. Galium aparine. Nevertheless, slight weaknesses in efficacy towards some tough to control dicotyledons (e. g. Cirsium arvense) became evident applying the set rates and applications timings of Roundup Utra within the protocol and need to be issued in the ongoing investigations. The assessments on sugar yield revealed no significant differences between the whole range of Roundup Ultra and conventional herbicide treatments. In order to obtain secured validity the results of both following trial years are essential.