Post-Plant Nematicides for the Control of Root Lesion Nematode in Red Raspberry

Abstract

<jats:p>To identify a post-plant nematicide to control root lesion nematode [RLN (<jats:italic>Pratylenchus penetrans</jats:italic>)] in red raspberry (<jats:italic>Rubus idaeus</jats:italic>), a number of nematicides was tested in soil-only and plant-based experiments. In soil-only experiments, soil naturally infested with RLN was drenched with the nematicides and nematode survival was assessed 7 and 14 days after treatment. Fosthiazate and oxamyl reduced RLN recovery 92% and 52% across trials and sampling times, respectively, compared with the nontreated control. Other nematicides that resulted in moderate, and sometimes inconsistent, control of RLN were soapbark (<jats:italic>Quillaja saponaria</jats:italic>) saponins, 1,3-dichloropropene, and methomyl. In plant-based experiments, ‘Meeker’ red raspberry was established in pots with RLN-infested soil mixed with greenhouse soil and the nematicides were applied as soil drenches or as a foliar application. Nematode recovery and cane and root weights were quantified as measurements of nematicide toxicity and phytotoxicity, respectively. Similar to soil-only experiments, fosthiazate and oxamyl were the most effective nematicides tested in reducing RLN population densities in established red raspberry. Fosthiazate and oxamyl significantly reduced RLN per gram dry root population densities by 97% and 87%, respectively, compared with the infested, nontreated control. None of the other nematicides reduced RLN population densities compared with the infested, nontreated controls. There was no phytotoxicity to red raspberry associated with any of the nematicides.</jats:p>

New reduced-risk agricultural nematicides - rationale and review

“…In the same study, no effects were observed on final population densities of M. xenoplax on peach with the same treatments. Other greenhouse studies with spirotetramat did not demonstrate any measurable effects on P. penetrans ( Zasada et al, 2010 ), M. incognita ( Baidoo et al, 2017 ), and Aphelenchoides ritzemabosi ( Chalanska et al, 2017 ). In a number of tree and fruit crop trials in California with spirotetramat, percentage reductions of plant-parasitic nematodes ( Xiphinema americanum, X. index, Pratylenchus vulnus, Tylenchulus semipenetrans, Meloidogyne spp., and Criconemoides xenoplax ) were around 50% across the different crops, provided that irrigation was delayed for two weeks following treatment ( McKenry et al, 2009 ).…”

Nematicidal activity of fluensulfone against some migratory nematodes under laboratory conditions

“…in the field, fluensulfone application rates will be much higher than those for Meloidogyne spp., which are suggested to be about 4 kg ha −1 by the manufacturer. In fact, fluensulfone even at 10 kg ha −1 was less effective in controlling P. penetrans in pot experiments with or without red raspberry as host plants than fosthiazate or oxamyl at lower concentrations . Higher application rates of nematicides are also generally needed for Pratylenchus than for Meloidogyne , although differences in environmental conditions, such as soil type and temperature, are known to affect nematode control efficacy .…”

Effect of Application Timing of Oxamyl in Nonbearing Raspberry for Pratylenchus penetrans Management

“…Oxamyl is an effective postplant nematicide, but it does not eliminate all nematodes from an application area. In controlled experiments, oxamyl reduced population densities of P. penetrans in raspberry roots by 88% compared with the nontreated control (Zasada et al, 2010). In field trials, two banded applications of oxamyl in spring reduced population densities of P. penetrans in roots of raspberry 'Willamette' by 94% compared with the nontreated control (Walters et al, 2009).…”

“…In raspberry, we demonstrated that a spring application of oxamyl to bearing raspberry plants reduced P. penetrans population densities for up to 2 years, but fall oxamyl applications were not effective (Walters et al, 2009). When trying to identify postplant nematicides alternatives for the Washington raspberry industry, oxamyl was superior to many of the other tested nematicides in suppressing P. penetrans (Zasada et al, 2010). Because of the proven efficacy of oxamyl against P. penetrans in raspberry, having this nematicide available to manage P. penetrans is an important tool for raspberry growers.…”