Anaerobic soil disinfestation as a tool for nematode and weed management in organic sweetpotato

Authors: SINGH, SIMARDEEP - Clemson University; CUTULLE, MATTHEW - Clemson University; Rutter, William; Wadl, Phillip; WARD, BRIAN - Clemson University; KHANAL, CHURAMANI - Clemson University

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2025
Publication Date: 2/24/2025
Citation: Singh, S., Cutulle, M., Rutter, W.B., Wadl, P.A., Ward, B., Khanal, C. 2025. Anaerobic soil disinfestation as a tool for nematode and weed management in organic sweetpotato. Agronomy Journal. https://doi.org/10.3390/agronomy15030548.
DOI: https://doi.org/10.3390/agronomy15030548

Interpretive Summary: of sweetpotato in the southeast. Anaerobic soil disinfestation (ASD) is a promising alternative to synthetic chemical-driven pest management methods. ASD removes oxygen from the soil and shifts the chemistry of the soil environment that has been shown to kill may weeds and soil borne pests before planting. to determine if ASD is a useful management for organically grown sweetpotato, we conducted greenhouse experiments using sealed buckets to investigate how ASD effects both SRKN and yellow nut sedge. We also tested the efficacy of twenty different types of sweetpotato to determine if they performed differently in ASD treated soils. Our results clearly show that ASD can significantly reduce the numbers of both SRKN and yellow nut sedge when compared with non-ASD treated controls. Furthermore,15 of the 20 ASD treated sweetpotato types showed an increase in both dry biomass and vigor compare to their non-ASD treated controls. Overall, our results indicate that ASD is a useful tool that can help manage both SRKN and yellow nut sedge in organic sweetpotato production operations. These results could help the many producers of organic sweetpotato in the Southeasten US, who are seeking to manage the damage caused by SRKN and/or yellow nutsedge in their operations.

Technical Abstract: Anaerobic soil disinfestation (ASD) is a promising alternative to synthetic chemical-driven pest management methods. ASD is facilitated by incorporating carbon sources into the soil, tarping the soil with plastic mulch, and irrigating to soil saturation. To evaluate the impact of ASD on nematode and weed management in organically grown sweetpotato, greenhouse studies were conducted on the main campus at Clem-son University. The treatments were structured as a factorial of two carbon amendments [chicken manure + molasses (CM+M), and no additional carbon (control)] by 20 sweetpotato genotypes with 4 replications using a randomized complete block design. Our results suggested that the microcosms receiving the carbon amendment spent the most time under anaerobic conditions (<200 mvh). Soil populations of nematode varied among the sweetpotato genotypes, with the lowest number observed in sweetpotato genotype ‘USDA-11-022’ (8/100 cm3 soil) under CM+M treatment. The commercial cultivar ‘Beauregard’ in the control group supported the greatest population of nematode (202/100 cm3 soil). Significantly lower nematode eggs (4,833/g root) were observed under CM+M treatments compared to the no carbon control (14,475/g of root). The application of CM+M reduced overall weed cover by 79% compared to the control. Sweetpotatoes in CM+M treated microcosms had significantly higher dry above-ground biomass (6.8 g) as compared to the control (3.6 g). The results of this study demonstrated that ASD has the potential to manage nematodes and weeds in organic sweetpotato production systems.