Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/5/2011
Publication Date: 1/5/2011
Citation: Timper, P., Davis, R.F., Aryal, S. 2011. Prevalence of Pasteuria SP. on Renfirom Nematode in a Georgia Cotton Field. National Cotton Council Beltwide Cotton Conference. Atlanta, GA. January 5-8, 2011.
Technical Abstract: Pasteuria species are bacterial parasites of nematodes and have been associated with suppression of root-knot, sting, and cyst nematode populations. Little is known about the Pasteuria sp. infecting the reniform nematode. While sampling a cotton field study near Cochran, GA, we found Pasteuria spores adhering to vermiform stages of the reniform nematode. Soil samples were collected in November 2009, June 2010, and November 2010 to determine the prevalence of Pasteuria sp. in locations differing in elevation, soil texture, and nematicide application. The average number of spores per nematode was used to estimate abundance of Pasteuria. Fewer Pasteuria spores were observed in the sandiest areas of the field and in locations treated with Telone than in the other locations. Similar numbers of spores were observed in the Temik treatment and the control, and there was no effect of elevation on spore abundance. It is likely that there was greater leaching of spores below the sampling zone in the sandier areas. Telone reduced populations of the reniform nematode, thereby reducing the number of available hosts for reproduction of Pasteuria sp. Mature spores of Pasteuria were observed within the body of juveniles and pre-infective females indicating that the bacterium can complete its lifecycle before plant infection occurs. There was a negative correlation between numbers of reniform nematodes and Pasteuria sp. (P < 0.0001; r = 0.618). As the proportion of nematodes with attached Pasteuria spores increased, the numbers of reniform per volume of soil decreased, indicating that the bacterium may be suppressing the nematode population.