Vertical distribution of nematodes in peanut-cotton cropping systems

Authors: Schumacher, Lesley; GRABAU, ZANE - University Of Florida

Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: 10/27/2021
Publication Date: 10/27/2021
Citation: Schumacher, L.A., Grabau, Z.J. 2021. Vertical distribution of nematodes in peanut-cotton cropping systems. Journal of Nematology. 53:1-32. https://doi.org/10.21307/jofnem-2021-095.
DOI: https://doi.org/10.21307/jofnem-2021-095

Interpretive Summary:

Technical Abstract: Cotton (Gossypium hirsutum) and peanut (Arachis hypogaea) are important field crops grown in the southeastern United States. The plant-parasitic reniform nematode (Rotylenchulus reniformis) is a pathogen of cotton capable of reducing lint yields, so crop rotation is commonly used for its management. One specific rotation system, sod-based rotation, uses two years of bahiagrass (Paspalum notatum) followed by one year each of peanut and cotton compared with a conventional crop rotation (peanut-cotton-cotton). Peanut and bahiagrass are poor hosts of reniform nematode. Agronomic benefits of a sod-based rotation like improved cotton root growth are well-known, but information about its effects on free-living, non-parasitic nematodes (fungivores, bacterivores, omnivores, predators) is limited. These nematodes contribute to soil nutrient cycling and may be beneficial in crop production. Additionally, reniform nematode is present deep in the soil profile, but not much is known about free-living nematodes at deeper depths. By surveying a long-term experimental site in Quincy, FL, our study aimed to investigate both plant-parasitic and free-living nematodes at different soil depths in sod-based and conventional rotation with or without irrigation. Soil samples were collected to a depth of 120 cm before planting (March 2017, March 2018), after harvest (October 2017, October 2018), and in the winter (January 2018, January 2019) using a hydraulic probe. Free-living and reniform nematode abundances were analyzed in 30 cm-sections. No irrigation effects were observed in any of the sampling dates (P>0.05). There were significant crop by depth interactions (P<0.05) for free-living nematode abundances for all sampling dates, but only in harvest sampling dates for reniform nematode abundances. For these interactions, effects varied by sampling date for free-living nematode abundances. Yet, sod-based rotation reduced reniform nematode abundances at all depths compared with conventional rotation for post-harvest sampling dates. Overall, both free-living and plant-parasitic nematodes were present up to 120 cm deep in the soil profile and cropping system affected nematode abundances.