Meloidogyne enterolobii is an emerging global threat and is damaging to sweetpotato (Ipomoea batatas) production in the southeast United States. Nematicide application is one of the few management strategies currently available against this nematode, and field testing is urgently needed. The objective of this study was to assess common nematicides for management of M. enterolobii and nontarget effects on free-living nematodes in sweetpotato field production. Treatments were (i) untreated control, (ii) fumigation using 1,3-dichloropropene, or at-transplant drench of fluorinated nematicides (iii) fluazaindolizine, (iv) fluopyram, or (v, vi) fluensulfone at 2 or 4 kg a.i./ha. In 2022, a field trial was conducted under severe M. enterolobii pressure and was repeated in 2023 in the same location without treatment rerandomization. Fumigation using 1,3-dichloropropene (1,3-D) was the only consistently effective nematicide at improving marketable yield relative to control and also consistently reduced most storage root galling measurements and midseason Meloidogyne soil abundances. Fluensulfone at 4 kg a.i./ha consistently improved total yield but not marketable yield, whereas fluensulfone at 2 kg a.i./ha, fluazaindolizine, and fluopyram did not improve yield. Each fluorinated nematicide treatment reduced at least one nematode symptom or nematode soil abundances relative to control, but none provided consistent benefits across years. Even with 1,3-D fumigation, yield was poor, and none of the nematicide treatments provided a significant return on investment relative to forgoing nematicide application. There were minimal effects on free-living nematodes. In summary, 1,3-D is an effective nematicide for M. enterolobii management, but additional management will be needed under severe M. enterolobii pressure.

Agroathelia rolfsii (anamorph: Sclerotium rolfsii) is a soilborne fungal pathogen that can cause disease on over 500 documented host species, including economically important field and vegetable crops. The pathogen commonly infects the stem or crown of most hosts, but it is also capable of damaging fruit and root structures that are near the soil line, resulting in wilting, stunting, and plant death. Two diseases caused by this pathogen are sclerotial blight and circular spot, both of which are detrimental for sweetpotato production. A. rolfsii is a necrotrophic pathogen and can be cultured from susceptible hosts and on artificial media. The purpose of this diagnostic guide is to provide characteristic traits for identifying A. rolfsii in sweetpotato as well as outline methods for pathogen isolation, morphological and molecular characterization, culture maintenance and long-term storage, and pathogenicity testing.