Camelina Response to Harvest Times and Sources of Seed Yield Loss.

Camelina (Camelina staiva L. Crantz) is an oilseed crop with the potential for dryland crop production in the Great Plains; however, pod shattering may cause significant yield losses. We determined the impact of different harvest times on camelina seed yield, water use efficiency, protein and oil content, and estimated biodiesel yield. Spring (Blaine Creek) and winter (BX WG1) camelina cultivars were harvested at three physiological maturity stages, corresponding to the three-digit BBCH scales of 805 (early harvest; 50% ripe pods), 807-808 (mid harvest; 70 to 80% ripe pods), and 809 (late harvest; >90% ripe pods).In addition, different harvest methods were assessed to identify and quantify other sources of yield loss. Seed moisture contents at early, mid, and late harvests were 14.2%, 9.79%, and 6.80%, respectively. On average, the seed yield of the early harvest was 7.96% and 22.4% higher than the mid and late harvests, respectively. The seed yield loss as a result of the mechanical disturbance imposed on the pods during direct harvesting was 7.25%, and 4.45% was due to the combine’s settings such as the fan speed and sieve size, making 11.7% total harvest loss. Camelina seed oil content was highest at mid harvest, but the estimated biodiesel yield was not significantly different between the early and mid harvests. This study demonstrates the importance of both harvest time and method in reducing camelina seed yield losses. Further studies aimed at developing new cultivars that are resistant to pod shattering or combines specially adapted for harvesting small seed crops such as camelina would be very important.