Camelina sativa: For Biofuels and Bioproducts - Industrial Crops: Breeding for BioEnergy and Bioproducts - page 165

Winter Varieties

Limited development of winter camelina lines exists today. High seed yield from
fall-seeded winter varieties remains to be proven [ 30 , 60 ]. The advantage of these
varieties is to allow the camelina seedlings to be in the soil when weather conditions
are optimal for emergence. Phenotypically, these varieties differ from spring
varieties in leaf shape and overwintering ability.
In the case of fall-seeded, the plant establishes itself in the fall and overwinters
as a rosette. The following spring, when temperatures reach 3.3 C, growth is
initiated and the plant emerges from the rosette and resumes growth [ 6 ]. The
vernalization requirement for winter camelina has not been well characterized.
Previous experiments have found that fall-seeded camelina has enough winter
hardiness to survive the harsh winters of Minnesota, where average winter air
temperatures are far lower than those found in Colorado [ 30 ]. As the plant is
already established, it reaches maturity far earlier than spring-seeded camelina.
Earlier maturity means that the plants are not exposed to as much of the heat and
drought stress that occurs during the warmest months of summer.
In addition to the potential for increasing yields, earlier harvest allows more time
for moisture recharge in the field during the summer. This could result in higher
yields for wheat that is planted after fall-seeded camelina than spring-seeded
camelina. This may vary based on spring temperatures and moisture conditions.
Another advantage of winter camelina is that fall planting is generally drier and the
seeds are already planted when spring rainfall arrives. Winter seeding of camelina
would be particularly advantageous in southeastern regions of the United States,
where the winters are warmer and the spring arrives earlier. In colder climates,
overwintering ability is increased with snow cover [ 61 , 62 ]. Aase and Siddoway
[ 61 ] determined that 7 cm of snow cover is sufficient to buffer wheat seedlings from
temperatures as low as 40 C. With the increased stubble as a result of the

implementation of no-till agricultural systems, there is a greater amount of snow
capture on fields.
Winter camelina trials in Akron, Colorado, have encountered failures related to
the presence of Ceutorhynchus cyanipennis and Ceutorhynchus americanus ([ 60 ,
B. Kondratieff and G.L. Hein (2011), personal communication). These insect pests
appear frequently on plant species in the Brassicaceae family, which includes
camelina [ 63 ]. These insects most strongly affect winter camelina that is planted
earlier in the fall, especially in August, as this is the time adult insects lay eggs
[ 63 ]. Later fall planting dates have been shown to reduce the impact of these pests.
Studies of winter camelina in Ireland have shown that earlier planting dates are
prone to high rates of lodging [ 64 ]. This also may be due to the damage from these
insects, as the larvae feed on stems at or below the soil line (G.L. Hein (2011),
personal communication).