Incorporating seeds in activated carbon pellets limits herbicide effects to seeded bunchgrasses when controlling exotic annuals

Authors: Davies, Kirk

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2017
Publication Date: 5/8/2018
Publication URL: https://handle.nal.usda.gov/10113/5945924
Citation: Davies, K.W. 2018. Incorporating seeds in activated carbon pellets limits herbicide effects to seeded bunchgrasses when controlling exotic annuals. Rangeland Ecology and Management. 71(3):323-326. https://doi.org/10.1016/j.rama.2017.12.010.
DOI: https://doi.org/10.1016/j.rama.2017.12.010

Interpretive Summary: Revegetation of exotic annual grass-invaded rangeland with pre-emergent herbicides is challenging because seeding is delayed until herbicide toxicity has diminished, but at this time, exotic annuals can be re-invading. Incorporating seeds into activated carbon pellets may protect seedlings from pre-emergent herbicide damage because activated carbon can neutralize the herbicides around the seedling. I evaluated using activated carbon pellets with species seeded at the same time imazapic was applied to control exotic annual grasses. Bunchgrasses had greater density and growth when incorporated into activated carbon pellets compared to seeded as bare seed. This suggests that activated carbon pellets can be used to protect seeded bunchgrasses from imazapic applied to control exotic annuals.

Technical Abstract: Revegetation of exotic annual grass-invaded rangeland with pre-emergent herbicides is challenging because seeding is delayed until herbicide toxicity has diminished, but at this time, exotic annuals can be re-invading. Incorporating seeds into activated carbon pellets may allow seeding to occur at the same time as exotic annuals are controlled with a pre-emergent herbicide because activated carbon can neutralize the herbicide in the microsite around seeds. I evaluated using activated carbon pellets with six species seeded at the same time imazapic was applied to control exotic annual grasses at two sites. Two of the six species establish enough at one site to evaluate the effects of pellets. These two bunchgrasses had greater density and growth (height, leaf length, number of stems and leaves) when incorporated into activated carbon pellets compared to seeded as bare seed. This demonstrates activated carbon pellets can be used to protect seeded bunchgrasses from imazapic applied to control exotic annuals.