Meloidogyne incognita management by nematicides in tomato production

Abstract

Meloidogyne incognita (southern root-knot nematode, SRKN) is a major pest in tomato (Solanum lycopersicum) production in the Southeastern United States. Management has relied on fumigant and carbamate non-fumigant nematicides. New non-fumigant nematicides, such as fluopyram, are available and field evaluation of new nematicides is needed. The objectives of this research were to assess the efficacy of new (fluopyram) and established (oxamyl) nonfumigant nematicides as well as fumigation (1,3-dichloropropene) for (1) SRKN management, and (2) impacts on total soil abundances of non-target, free-living nematodes in field tests in Florida. Fumigation with 1,3-D consistently managed SRKN and, in two of three trials, increased yield relative to untreated. Oxamyl and fluopyram also had efficacy in managing SRKN, but were inconsistent from year to year. Oxamyl provided better root galling control than fluopyram in one of two trials, but otherwise those nematicides provided similar SRKN management and yield response. Supplementing 1,3-D fumigation with fluopyram did not improve SRKN management or yield relative to fumigation alone. Fumigation consistently reduced free-living nematode abundances relative to untreated. Oxamyl and fluopyram were more inconsistent, but always reduced total free-living nematode abundances when effective against SRKN. In summary, while non-fumigant nematicides provided some management of SRKN, fumigation continued to be the most consistent option. All nematicides had deleterious effects on free-living nematodes.

Meloidogyne incognita Management Using Fumigant and Non-fumigant Nematicides on Sweet Potato

“…While oxamyl is registered for RKN control on sweet potato and the effect of oxamyl on various RKN in various crops has been demonstrated ( Wright and Rowland, 1982 ; Gugino et al ., 2006 ; Peiris et al ., 2021 ), efficacy of oxamyl against SRKN in sweet potato is minimal, so this study provides important efficacy data. Although many studies have proved the efficacy of fluopyram against RKN on various crops ( Faske and Hurd, 2015 ; Jones et al ., 2017 ; Dahlin et al ., 2019 ; Hajihassani et al ., 2019 ; Ji et al ., 2019 ; Grabau et al ., 2021 ), it showed little value for managing SRKN in this study. The application methods used in this trial could have contributed to the lack of fluopyram efficacy in this trial as it was only applied through chemigation in 1 of 3 yr of this study and that is the current label recommendation as well as the method used in most studies where fluopyram has been effective ( Ji et al ., 2019 ; Grabau et al ., 2021 ).…”

“…Although many studies have proved the efficacy of fluopyram against RKN on various crops ( Faske and Hurd, 2015 ; Jones et al ., 2017 ; Dahlin et al ., 2019 ; Hajihassani et al ., 2019 ; Ji et al ., 2019 ; Grabau et al ., 2021 ), it showed little value for managing SRKN in this study. The application methods used in this trial could have contributed to the lack of fluopyram efficacy in this trial as it was only applied through chemigation in 1 of 3 yr of this study and that is the current label recommendation as well as the method used in most studies where fluopyram has been effective ( Ji et al ., 2019 ; Grabau et al ., 2021 ). However, fluopyram was not effective in the 1 yr it was applied as a drench, suggesting that a change in application methods may not improve efficacy in this situation.…”

“…Despite being an established chemistry, there is relatively little prior information on non-target effects of oxamyl. In tomato field production, oxamyl always had non-target effects on free-living nematodes (total soil abundance) when it effectively managed SRKN ( Grabau et al ., 2021 ). Similarly, in microcosm ( Carrascosa et al ., 2015 ) and field studies (Ntalli et al ., 2018) in tomato production, oxamyl also negatively affected free-living nematodes.…”

“…In recent years, several new fluorinated non-fumigant nematicides became available, including fluensulfone, fluopyram, and fluazaindolizine, and have been found to be effective in managing root-knot nematodes (RKN) on several vegetable crops in greenhouses and field studies ( Becker et al ., 2019 ; Desaeger and Watson, 2019 ; Khanal and Desaeger, 2020 ; Grabau et al ., 2021 ). These new discoveries may provide growers alternatives to fumigants for nematode management.…”

Plant Genotype Shapes the Soil Nematode Community in the Rhizosphere of Tomatoes with Different Resistance to Meloidognye incognita

“…Along with continuous cropping for a long time, a successive cropping obstacle occurs in tomato greenhouses and results in serious soil-borne diseases, such as root rot and root-knot nematodes [ 1 ]. Specifically, root-knot nematode disease caused by M. incognita is the major problem of tomatoes in greenhouses [ 2 ] and needs to be controlled. Planting resistant cultivars is the most effective and economical way to control M. incognita [ 3 ].…”