With backpack vacuums, the research team went looking for nonnative plant seeds on air-intake grilles of refrigerated shipping containers — and found thousands of them.

Seeds that float in the air can hitchhike in unusual places — like the air-intake grille of a refrigerated shipping container.

A team of researchers from the USDA Forest Service, Arkansas State University, and other organizations recently conducted a study that involved vacuuming seeds from air-intake grilles over two seasons at the Port of Savannah, Georgia.

Imported refrigerated shipping containers are inspected by the U.S.

Seeds from 30 plant taxa were collected from the air-intake grilles, including seeds of wild sugarcane (Saccharum spontaneum), a grass on the USDA Federal Noxious Weed List.

“During the two shipping seasons, we estimate that over 40,000 seeds from this species entered the Garden City Terminal at the Port of Savannah,” says Rima Lucardi, a Forest Service researcher and lead author of the project.

“This quantity of incoming seeds is more than sufficient to cause introduction and establishment of this nonnative invader, even If the escape rate from the shipping containers is limited.”.

To estimate the chance that seeds would survive and establish in the U.S., Lucardi and her colleagues analyzed and modeled viable seeds from four plant taxa.

For example, in lieu of labor-intensive vacuuming of air-intake grilles, a liquid pre-emergent herbicide could potentially be applied to containers while in port.

Prevention and best management practices, from the farm to the store, reduce the probability of nonnative seeds establishing in the U.S.

Inspection for exterior seeds hitching a ride on shipping containers at their points-of-origin or stops along the way would also reduce risk of invasion.

“Investment in the prevention and early detection of nonnative plant species with known negative impacts results in nearly a 100-fold increase in economic return when compared to managing widespread nonnatives that can no longer be contained,” says Lucardi.

Reference: “Seeds attached to refrigerated shipping containers represent a substantial risk of nonnative plant species introduction and establishment” by Rima D.

September 9, 2020

September 9, 2020

September 9, 2020