Vertical Distribution and Population Dynamics of Nematodes As Influenced By Crop Rotation and Irrigation

Sod-based rotation uses two years of pasture bahiagrass (Paspalum notatum) followed by one year each of peanut (Arachis hypogaea) and cotton (Gossypium hirsutum) to improve cotton yield, soil fertility, and water infiltration versus a conventional crop rotation (peanut-cotton-cotton).  Reniform nematode (Rotylenchulus reniformis, RN) is a pathogen of cotton, but not peanut or bahiagrass, so sod-based rotation may be an effective tool for its management.  The most common plant parasite at the research site is RN.  Currently, little information exists on dynamics of RN movement within individual fields (Monfort et al., 2008).  Initial research has shown that RN is present deep in the soil profile, but little is known about population dynamics (i.e. numbers of females, juveniles, and males) at depths.  My goal is to understand the vertical distribution of RN life stages as well as beneficial, free-living nematodes and determine if this information will assist growers with crop rotation, irrigation scheduling, and/or nematicide application throughout the growing season.  The purpose of this research is to provide growers with a solution for improving soil health and reducing nematode damage, particularly by RN, using a sod-based rotation versus a conventional peanut-cotton rotation.  Another purpose is to understand the vertical soil distribution of this pest in relation to total nematode community structure to better assist with management practices.