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

Abstract

Southern root-knot nematode (SRKN, Meloidogyne incognita) is a major pest of sweet potato, and nematicides are needed to manage this nematode. The objectives of this study were to assess the efficacy of fluazaindolizine, a new non-fumigant nematicide, in comparison with the fumigant nematicide 1,3-dichloropropene (1,3-D) and non-fumigant nematicides fluopyram and oxamyl for (1) SRKN management, (2) impacts on free-living nematodes, and (3) sweet potato yield in field trials. Among all nematicides, 1,3-D at 84 kg/ha most consistently (2 of 3 years) managed SRKN soil populations and improved yield. Fluazaindolizine at 2.24 kg/ha and fluazindolizine at 1.12 kg/ha plus oxamyl at 2.14 kg/ha managed SRKN populations and improved yield in 1 of 3 years, whereas fluazaindolizine alone at 1.12 kg/ha only decreased SRKN populations. Fluopyram at 238 g/ha did not affect SRKN or yield. Nematicide application also had non-target effects on free-living nematodes with 1,3-D reducing abundances relative to untreated most frequently (2018 and 2020), but other nematicides also reducing free-living nematode abundances in 2020. In summary, 1,3-D is the most consistent option for SRKN control on sweet potato, but fluazaindolizine, oxamyl or combinations of the two products can also be effective.

Evaluation of fumigant and non-fumigant nematicides for management of Rotylenchulus reniformis on sweetpotato

“…Despite suppression of reniform nematode populations using 1,3-dichloropropene, the current study did not demonstrate a yield benefit of soil fumigation in either of the trial years. These results are in contrast with other studies with soil fumigants on sweetpotato, which have demonstrated yield benefits through application of 1,3-dichloropropene in a reniform nematode infested field in Mississippi (Abel et al, 2007) and in a southern root-knot nematode infested field in Florida (Liu and Grabau, 2022). Despite the apparent lack of yield response to soil fumigation observed in the current study, which may have been related to high variability in yield among treatments, applying 1,3-dichloropropene still resulted in a numerical increase of 36% more U.S.#1 sweetpotato per hectare relative to the untreated plots in 2021, and 31% more in 2022.…”

“…The duration of nematode population reduction varied greatly by trial year. 1,3-dichloropropene provided season-long reduction in reniform nematode soil population densities in 2021; however, in 2022, the and Grabau, 2022). The relatively short duration of nematode population reduction achieved with soil fumigants could be associated with the short halflife of these products (Desaeger et al, 2020) and the negative impact they have on soil suppressiveness (Watson et al, 2020;Watson et al, 2017), each of which are factors that would favor reinfestation of fumigated soil.…”

“…et al, 2007). In a Florida sweetpotato field infested with southern root-knot nematode, drench application of fluazaindolizine showed relatively consistent suppression of nematode populations, while suppression was more variable with oxamyl among trial years and not observed with fluopyram; however, the yield benefit of nematicide application was inconsistent and often unrelated to suppression of nematode population densities (Liu and Grabau, 2022). In a California sweetpotato field infested with southern root-knot nematode, pre-plant application of fluensulfone provided relatively consistent yield increase and supressed nematode egg production of sweetpotato; however, no differences were observed in soil population densities of infective juveniles (Ploeg et al, 2019).…”

Distrubution of meloidogyne chitwoodi in potato plants in Ganja-Gazakh economic region

“…Lakin L, VG, stilet və hialin uzunluğu kimi bəzi morfometrik göstəricilər bizim tərəfimizdən tapılan növün bəzi populyasiyalarında verilən təsvirdən fərqlidir (Golden et al, 1980;Karssen, 1996) [5]. İkinci mərhələ sürfələrinin morfoloji xüsusiyyətlərini qiymətləndirən bir araşdırmada çox yüksək morfoloji variasiya bildirildi (Humphreys-Pereira & Elling, 2015) [8]. Tədqiqatımızda bəzi sürfələrdə düz bağırsağı müşahidə edə bilmədik.…”

“…M. chitwoodi qışı yumurta və ya yetkin halda keçirir və sıfırdan aşağı temperaturlarda uzun müddət canlılığını saxlaya bilir. Bu növün yumurtadan çıxması və köklərə nüfuz etməsi üçün 4°C, inkişafı üçün isə 6°C temperatur lazımdır [8].…”