- Two of the world's worst weeds are in cahoots with one of the world's worst roundworm crop pests, reducing yields up to 40 percent in chile peppers and 25 percent in cotton.
Thomas has suggested several possible directions for future research:
Identifying other crop varieties that resist the nematodes, can compete against the nutsedges, and give growers more flexibility than three years of alfalfa. Pearl millet may have potential as a summer forage crop for local dairies, according to Thomas.
Incorporating CT scanning technology, which would allow researchers to see into the nutsedge tubers and learn how the two pests affect each other's development in hopes of finding weak points.
Exploring how to use winter accumulation of soil heat units and irrigation timing as tools to determine when to disrupt the early season impact of nutsedges and root-knot nematodes on young crops.
The value of the latter two research directions would be in better understanding of the relationship of nutsedge germination and nematode emergence. More precise prediction of these stages would allow producers to be more precise with their treatment efforts.
Beyond the knowledge gained about how this specific pest complex functions, the project has led to the development of strategies for identifying and investigating other pest complexes.
"We have started a collaboration with Soum Sanogo, an associate professor in EPPWS, to understand the interactions of three annual weeds—spurred anoda, Wright groundcherry and tall morning glory—with the nematodes and the Verticillium fungus," Schroeder said. "The research is based on observations made by Sanogo in the Deming area in fields infested with all these pests.
"The root-knot nematode and Verticillium pathogens infect all three weeds but the weeds are not damaged. As a matter of fact, the tall morning glory grew better when infected with these pests that are devastating to chile. We are beginning to think that these predominant annual weeds in Southwestern chile pepper production systems may actually enhance populations of both pathogens, reinforcing the importance of effective weed management for effective management of the disease. We plan to continue research on the biology of this interaction."