Jointed
goatgrass closely resembles the life cycle of winter wheat.
Spikelets
(joints) can germinate in the fall or spring and produce
viable seed.
JGG seed
can remain viable for five or more years.
Seed
will remain viable longer in reduced rainfall areas.
Jointed goatgrass
closely mimics the life cycle of winter wheat. Seeds germinate
in the fall, plants overwinter, and resume growth in the spring.
Although seeds typically germinate in the fall, jointed goatgrass
can also germinate during March and April and still produce
viable seed. Jointed goatgrass matures and shatters seed
on the soil surface during, or up to three weeks before wheat
harvest. Spring germinating plants usually mature and
produce seed later than fall germinating plants. Scientists
in Washington recently discovered that jointed goatgrass can
produce seed with no vernalization (overwintering or chilling)
event. It was not clear whether a population of jointed goatgrass
could become a serious problem in spring cereals as it is in
winter wheat because of spring germinating plants. However,
rotating only to a spring cereal may not completely eliminate
jointed goatgrass seed production in that crop.
Seed
can remain viable for five years or more, especially when
deeply buried. Seed will typically decay faster in a
region with higher precipitation. A study in the Pacific
Northwest showed seed remained viable for over five years
in a 10-inch rainfall area compared to less than three years
in a 22-inch rainfall area. In addition, most jointed goatgrass
seed will germinate from a depth of 0 to 2 inches in soil.
Approximately 80% of the seed
at this depth will germinate within three years. Some
seed can emerge from 2 to 3 inches, but very few will emerge
from more than 4 inches. The optimum temperature for
germination is 68◦ F and the optimum range
is 50◦ to 86◦ F. Some
germination may occur as low as 36◦ F and
as high as 104◦ F.
Contact
us: yenish@wsu.edu
, 509-335-2961 | Accessibility
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Joe Yenish, Extension Weed Scientist, Washington State University,
PO Box 646420, Pullman, WA, 99164-6420 USA
