Comparative Within Field Dispersal Patterns of Aphid and Whitefly Transmitted Viruses

Thomas V. Orum, Athar Nadeem , Larry J.Stowell and Merritt R. Nelson

Within field dispersal characteristics of an aphid-transmitted potyvirus (water melon mosaic 2) and a whitefly transmitted geminivirus (cotton leaf crumple) were compared. Despite differences in the virus, the insect vector and the host plant, within-field patterns of infection were similar for both systems studied at two spatial scales. Ordinary runs analysis and sample variogram analysis of individual plant data suggest plant to plant spread within rows over a range of 3 to 5 plants (0.5 to 2.5 m) and variogram analysis of quadrats suggests spatial structure (non-random spatial patterns) of incidence over a range greater than 15 meters. Sample variogram values in the direction perpendicular to row orientation (north-south) were higher than sample variogram values in the direction of row orientation (east-west) at both scales in both virus/vector/host systems. These observations are consistent with spread of the virus occurring faster within rows than between rows in a field.

View Fulltext Back