The Science Seminar Series: April 1, 2010
Biological Control of Root-Knot Nematodes
Patricia Timper, Ph.D.
Research Plant Pathologist, USDA ARS
Time: 4:00 -5:00pm
Nematodes are roundworms, often microscopic, that are abundant in our environment. Some nematodes are parasites of animals (e.g., dog heart-worm) and plants, but most are non-parasites. Root-knot nematodes are plant parasites which cause significant yield losses in a wide variety of crop plants by damaging their root systems. I am interested in understanding how crop production practices such as tillage, crop rotation, and pesticide application influence natural biological control of root-knot nematodes. Organisms that prey on or parasitize nematodes are common in soil and sometimes these organisms reach levels that suppress populations of root-knot nematodes. My ultimate goal is to indentify practices that enhance the activity of these beneficial organisms. In one study, I am testing the hypothesis that some crop rotations are better than others for increasing the abundance of Pasteuria penetrans, a bacterial parasite of root-knot nematodes. In another study, I am testing the hypothesis that application of a nematicide reduces the abundance of predatory nematodes (beneficial nematodes) and that this will lead to greater populations of plant-parasitic nematodes. The concern is that root-knot nematodes may rebound faster from the nematicide, because of their higher reproductive rate, than the predatory nematodes.