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Submitted to: Society of Nematology Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 7/9/2005 Publication Date: 9/15/2005 Citation: Timper, P. 2005. Effect of cropping systems on abundance of Pasteuria penetrans [abstract]. Journal of Nematology. 37:399 Interpretive Summary: Technical Abstract: Few studies have examined the impact of agricultural practices on biological control of nematodes. We have been conducting ongoing studies in Georgia to determine the effect of crop rotation and nematicides on abundance of Pasteuria penetrans. This bacterium is an obligate parasite of root-knot nematodes and is naturally present at low levels in most peanut fields in Georgia. In a 9-year field study, crop rotation had a dramatic affect on densities of Pasteuria endospores in soil. In the continuous peanut plots, endospore densities were extremely high, and Pasteuria suppressed reproduction of Meloidogyne arenaria by 91%; whereas in a cotton-peanut rotation, endospore densities were very low. Endospore densities in other rotations corresponded to how frequently a host for M. arenaria was grown. Reproduction of the nematode was suppressed by 76% in plots where a host plant was present 2 out of 3 years in a sequence. Frequent planting of peanut to increase the level of Pasteuria is unwise because it will lead to an increase risk of other soil-borne diseases. The question we are currently trying to address is: can we utilize an agronomically sound cropping system to increase the abundance of Pasteuria and create nematode-suppressive soils in growers fields? During the transition from nematode-conducive to nematode-suppressive soil, nematode populations may need to be held in check by nematicides. Previously, we found the application of aldicarb at planting did not influence densities of Pasteuria endopsores; however, other nematicides and fumigants need to be evaluated. |
