Ethiopian Mustard (Brassica carinata) Response to Seeding Rates at Two Locations in South Dakota.

Production of fuel from alternative, plant-based sources has become an area of interest as a means of reducing the nation’s dependency on foreign oil and diversifying cropping systems. Ethiopian mustard (Brassica carinata), a non-food oilseed, has recently been identified as a potential biofuel crop for the semi-arid environments of central and western South Dakota due its agronomic qualities which include: drought tolerance, heat tolerance, and high oil content. However, the best management practices for B. carinata in South Dakota have yet to be developed.  In 2016, a seeding rate study was conducted at two locations, Brookings (conventional till) and Pierre (no-till), in South Dakota. The objective was to evaluate the response of two B. carinata varieties (‘A110’ and ‘A120’) to four seeding rates (4.5, 9, 13, and 17.5 kg/ha).  The study was arranged as a randomized complete block design with treatments replicated four times. Under no-till conditions at Pierre, the optimal seeding rates ranged from 9 to 17.5 kg/ha.  Under conventional till at the Brookings location, the optimal seeding rates were slightly lower ranging from 4.5 to 13 kg/ha. The two varieties yielded the same at the Pierre location, while at the Brookings location ‘A120’ had greater yield than ‘A110’, with yields of 1320 and 1151 kg/ha, respectively. These preliminary results suggest that B. carinata can compensate for low plant populations via branching, thus optimal yields can be achieved at a wide range of seeding rates. The study will be repeated at both locations in 2017.