Resumen
- Densities of reniform nematode, Rotylenchulus reniformis, can change in time and space within a field affecting samplingand management strategies. A three-year study was conducted in two fields in South Carolina to assess the horizontal andvertical distribution of reniform nematode and determine potential correlations with soil texture. Cotton-peanut and cotton-corn-soybean rotation systems occurred in fields 1 and 2 respectively. Each year, soil samples were collected in both fields atplanting and after harvest. In field 1, 40 samples were collected at random locations. Sample cores were separated into fourdepths: 0-15 cm, 15-30 cm, 30-60 cm, and below 60 cm. In field 2, samples were collected from 80 4x4mplots distributedwithin four sections of the field representing different soil electrical conductivity readings and textures. Reniform nematodedensities within each field/plot showed high levels of spatial variability during the length of the study. Horizontal distributionanalysis using the variance/mean ratios showed a significant clustered distribution at planting and after harvest in both fieldsduring the three years. However, a significant neighbourhood structure was only detected in the first two years in field 2, withpatches between 8 and 18 square meters. Vertical analysis showed the highest numbers of reniform nematode between 15-and 30-cm deep. In some of the plots R. reniformis densities were significantly correlated with sand and clay content. In thisstudy, the choice of sampling strategy, host as well as soil texture affected the spatial pattern of reniform nematode that wasrevealed