Base Temperature Determination of Spring Camelina Cultivars.

Timely planting plays an important role in successful crop production and this is usually determined by estimation of accumulated degree heat units from a base temperature, which is crop specific. Previous studies determined the base temperature of camelina using the x-intercept method, where emergence rate per day (ERPD) is regressed on temperature to obtain the temperature when ERPD is zero. The method requires incubating seed lots maintained at constant temperature and at several different temperatures. For a cold tolerant crop such as camelina (Camelina staiva L. Crantz), the base temperature (-0.53 to -1°C) was extrapolated beyond the temperature range used in the experiment (0 to 16°C). We determined the base temperature of two spring camelina cultivars using modification to the least variability method. We first performed a seed germination test at different temperatures (-2, 2, 4°C) to obtain a temperature range from which to predict the base temperature. This was followed by planting camelina on different dates in two greenhouses, and growing degree days (GDD) for emergence calculated by varying the base temperature to obtain the temperature in which the standard error across the various plantings was least. The base temperature was found to be 0.51 and 0.45°C for Ligena and Pronghorn spring camelina cultivars, respectively. The result suggests that camelina is relatively cold tolerant and can be seeded early in the spring.