Location: Crop Protection and Management Research
2012 Annual Report
2. Develop integrated strategies and control options for managing nematodes in cotton and peanut. 2.a. Enhance the efficacy and consistency of biological control of nematodes. 2.b. Identify new cultural control options for managing nematodes in cotton and peanut. 2.c. Develop integrated approaches for managing nematodes.
A field study is underway to evaluate the influence of tillage and fumigation with 1,3-dichloropropene on abundance of the nematode parasite Pasteuria penetrans. We have collected soil from this field site and determined the abundance of P. penetrans spores in the different treatments. We have also set up a greenhouse study to determine reproductive potential of the southern root-knot nematode in the different treatments. This is the first of a multi-year study.
We completed two greenhouse trials to determine the efficacy of Paecilomyces lilacinus (a fungal pathogen of nematodes marketed as NemOut) on different crop plants. The greatest percentage suppression of root-knot nematodes by the fungus was in peanut (67%) and the lowest was in corn (26%); suppression in cotton was intermediate (40%). In another greenhouse experiment, we found that suppression of root-knot nematodes in cotton by P. lilacinus was enhanced when a rye cover crop was grown before planting cotton. The rye was grown for a month and then killed with a herbicide before P. lilacinus was applied along with a cotton seed to the soil. In two trials of this experiment, nematode suppression by the fungus averaged 36% in fallow soil and 63% in soil that had a rye cover crop. One additional trial of the cover crop experiment is needed before the results can be published.
Preliminary greenhouse tests were completed on 82 sorghum entries evaluating their suitability as a host for Meloidogyne incognita, the cotton root-knot nematode. We documented widely varying levels of nematode reproduction ranging from 0 to 379% of the eggs per plant measured on corn, a susceptible plant used as a standard for comparison. Approximately a third of the entries tested had a high level of resistance and should be a useful genetic resource for sorghum breeders. Field tests have been initiated to determine how much damage the nematodes cause to susceptible entries.