Camelina and canola seem to be the frontrunners in the race to find new biofuel feedstock crops for California.

University of California agronomist Steve Kaffka has several years of trials on these crops, including three consecutive years of comparison trials at Davis, Calif., and Five Points, Calif., at the Westside Research and Extension Center (WREC), where he updated his work for an agronomy day.

Yields are higher at Five Points than at Davis, but it may take more water to grow the crops in the Central San Joaquin Valley than at Davis, where there is more rainfall.

The key to economic success with these crops is oil yield.

“You need 150 to 200 gallons of oil per acre to be successful” in California cropping systems, he says.

Canola achieved that in 2010 trials at Davis and Five Points, Kaffka said at the WREC field day. Canola yielded 2,563 pounds per acre in Davis that year and almost 3,400 pounds at WREC. Oil yields then were 163 and 190 respectively.

However, it has been a struggle to achieve those yields the past two seasons. In 2011 the yield at Davis was only 748 pounds per acre and just 50 gallons of oil and 2,004 pounds per acre and just 113 gallons of oil per acre at WREC. Kaffka attributes the low yields to a cold, wet spring that season.

This season, it was a disaster at WREC with a yield of just 890 pounds per acre. He does not have oil yield yet. He attributed the disastrous yield to herbicide drift injury. At Davis the canola yielded 2,290 pounds per acre.

Camelina did not fare nearly as well compared to Canola any season. The yields ranged from 2,015 pounds per acre at WREC in 2010 to a low of just 254 pounds there this season. Davis yields have been 970 and 591 pounds per acre for the past two seasons. The oil yield reached 100 gallons per acre only with the 2010 camelina yields at WREC.

Camelina is a low water and nitrogen user, Kaffka says, needing only about 60 to 80 pounds of N per acre. It requires 13 to 18 inches of water, which means in many areas of the state it could be produced on winter rainfall alone. In other areas like the central and southern San Joaquin valley, it likely would require one supplemental irrigation with normal average winter rainfall.