By TESA NAUMAN
Tennessee Correspondent

CHAMPAIGN, Ill. — Many in the biomass industry see crops such as switchgrass as seeds of the future, for their potential in making “greener” fuels and alternative energy sources; however, a threat to those crops might be lurking around the corner, say researchers.

According to an article from the University of Illinois, a small caterpillar known as the tiller-killer has been documented in switchgrass across the Midwest by a team of researchers at the Energy Biosciences Institute (EBI) at the UoI. In addition, this team has recently identified fall armyworms, corn leaf aphids and yellow sugarcane aphids as other potential pests.

“Our goal is to discover perennial grass pests now so we can study their potential impact before these grasses become widespread. However, finding insects does not necessarily indicate a problem,” explained Mike Gray, leader of the team of researchers and a UoI entomologist.

At the Bioenergy Feedstocks Symposium in Champaign, Ill., on Jan. 11, Gray’s fellow team member, Jarrad Prasifka, presented its research and goals. It has been conducting surveys and searching for pests on biomass crops for the last two years.

“As biomass production increases, pests will react to the new resources we put out and make available to them,” Prasifka said. “In the United States, soybeans were considered a pest-free crop for many years. But now, soybeans, just like any other crop, have management issues related to both insects and diseases.”

Tennessee has just opened a new biorefinery where switchgrass is a major component of the biomass the refinery turns into biofuel. Sam Jackson, research assistant professor with the University of Tennessee Office of Bioenergy Programs and vice president of feedstock operations for Genera Energy LLC – one of the companies that owns the refinery – agrees it’s inevitable for pests that aren’t a current threat to switchgrass and other plants to crop up in the future.

“As (the plants) become more distributed across the landscape and become more common, you’ve got things that realize they like the taste of switchgrass or some of these other crops. So we recognize that pests will become an issue that will become larger as we go forward, and we’ll need methods to address those,” Jackson said.
He said in the North and Midwest, pests with such ominous names as the fall armyworm and tiller-killer caterpillar feed on switchgrass; however, in Tennessee, there haven’t been any significant switchgrass pests as yet.

“We expect to encounter things like that in the future. Right now, probably the biggest insect pests we have are insects that feed on the seed and the soil after we plant. But it’s not been to a level that’s affected our establishment (of the switchgrass).

It’s just something that we’ve noticed,” Jackson said.
He added the state has ongoing studies and monitoring to keep an eye out for pests and for diseases, which he expects could be more of a threat to Tennessee switchgrass.

“There are diseases such as rusts and fungus, and other issues that are out there. We have identified a couple of rusts, but they’re rusts that so far have not impacted the plants’ health or overall yield, so it’s not been an issue we’ve needed to treat. But, there are treatments available, mainly chemically, that would be able to treat rust should it became a significant issue.” Jackson said.
“Between pests and diseases, we’ve got quite a lot of work and focus going on, on them, but we haven’t encountered any significant problems yet.”