The influence of irrigation, crop rotation, and Fluopyram nematicide on peanut yield and the nematode community

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

Submitted to: Nematropica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/26/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Nematodes are microscopic roundworms that inhabit both aquatic and terrestrial environments. Some are beneficial and perform vital ecosystem services like soil nutrient cycling while others are considered plant pathogens. Sod-based rotation is an effective way to manage certain plant pathogens in southeastern United States cotton and peanut production, but how do the peanut phases of conventional and sod-based crop rotations affect nematode ecology? Investigating this at a long-term research site provided information on how the nematode ecology was affected by irrigation, crop rotation, and fluopyram nematicide. Ring nematode (a plant-parasitic nematode) was greater in the sod-based peanut than conventional peanut. Fungal feeding nematodes were generally greater in the sod-based peanut than conventional peanut. Conventional peanut outyielded sod-based peanut. Fluopyram nematicide did not significantly improve peanut yield compared to untreated plots. Overall, we observed few effects on nematodes from any of the factors. This work demonstrates how common cropping practices influence soil ecology and crop yield.

Technical Abstract: Peanut (Arachis hypogaea) is an important cash crop in the southeastern United States and suffers from yield losses due to plant-parasitic nematodes. Peanut is rotated with two years of cotton (Gossypium hirsutum) or one year of cotton and two years of sod (Paspalum notatum) in conventional and sod-based crop rotation, respectively. Little is known about how three common agronomic practices – irrigation, crop rotation, and fluopyram nematicide application – collectively influence peanut yield and nematode community structure. Therefore, objectives of this research were to determine effects of irrigation (with or without), crop rotation (conventional or sod-based peanut), and fluopyram nematicide application (with or without) on various nematode trophic groups, ecological indices, and peanut yield. Soil samples were collected before planting, at midseason, and at harvest in 2018-2019 at a long-term research site in Quincy, FL, USA. Free-living and ring nematodes (Mesocriconema ornatum) were extracted from a subsample using sucrose-centrifugation and nematode ecological indices (structure, maturity, channel, enrichment, and basal) were calculated. Overall, ring nematode population densities were greater in sod-based peanut than conventional peanut. Conventional peanut had greater yield than sod-based peanut plots. Fluopyram nematicide application did not improve peanut yield compared to untreated plots. We observed consistent trends with sod-based peanut increasing fungivores relative to conventional peanut. Yet, other nematode trophic groups and ecological indices were not consistently impacted by our factors. Therefore, nematode ecology was not heavily influenced by irrigation, crop rotation, or fluopyram nematicide in this research.