Weed control in buckwheat: comparison of five selected herbicides

Buckwheat is an orphan crop in Switzerland which has lately been gaining attention due to its gluten-free flour and the high biological value of its protein. In order to establish the conditions for conventional production of buckwheat, two pre-emergence and three post-emergence herbicides were tested as to their suitability for controlling weeds in this crop. The two pre-emergence herbicides, Dual Gold and Nimbus CS, generally exhibited very good control of dicots and grasses up to maturity. They also exerted a negative impact on the density of buckwheat, which did not, however, affect yield negatively. Betasana and Betam Combi RAL, both of which contained the active component ethofumesate, brought about a marked reduction in yield. This effect was a result of their phytotoxicity, as well as their delaying effect on growth and flowering time. The post-emergence herbicide Beetup, which was only moderately successful in controlling weeds, was nonetheless the only treatment bringing about a consistent yield increase of 2,8 dt/ha on average. The two herbicides Dual Gold and Nimbus CS were identified as being potentially promising for registration in Switzerland. In case of a registration of these herbicides harvesting could be made easier by means of direct threshing.