Submitted to: HortTechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/15/2009
Publication Date: 10/1/2009
Citation: Walters, T.W., Pinkerton, J.M., Riga, E., Zasada, I.A., Particka, M., Yoshida, H., Ishida, H. 2009. Managing plant-parasitic nematodes in established red raspberry fields. HortTechnology. 19:762-768. Interpretive Summary: Plant-parasitic nematodes are microscopic soil worms that attack raspberry plants and cause significant loss in yield to this crop annually. Raspberry farmers face an enormous problem because they lack effective ways of reducing the numbers of nematodes in soil after a raspberry crop has been planted. This research was conducted to identify products that can reduce nematode numbers in established raspberry fields. In four trials a range of products were applied to soils, and nematode numbers and raspberry yields were determined over several years. A spring application of the synthetic pesticides oxamyl and fosthiazate reduced nematode numbers. Other products that were tested but weren’t as effective included 1,3-dichloropropene (another synthetic pesticide), DiTera (a microbial-based product), and seed meal of Ethiopian mustard (Brassica carinata). For oxamyl the length of nematode suppression was related to the timing and rate of application, with a spring application being more effective than a fall application, and higher application rates resulting in a longer duration of nematode reduction. These results are significant because they will help guide the selection of products for plant-parasitic nematode control in raspberry. This research will be by used scientists and farmers to manage plant-parasitic nematodes in established raspberry fields.
Technical Abstract: The efficacy and phytotoxicity of post-plant treatments to control root lesion [Pratylenchus penetrans (Cobb), Chitwood & Otiefa] and dagger (Xiphinema bakeri Williams) nematodes in red raspberry (Rubus idaeus L.) were evaluated in four field studies conducted over three years. Spring spray applications of oxamyl or fosthiazate reduced P. penetrans and X. bakeri population densities significantly for up to two years, but fall oxamyl sprays and spring drip-applied oxamyl applications were not effective. Oxamyl application rate determined the duration of nematode supression. Two spring applications of 2 lb oxamyl/acre provided more than two years of supression, while two spring applications of 0.8 lb/acre supressed nematodes for only one year. Spring oxamyl applications reduced ‘Nootka’ fruit yield for one season, but did not affect ‘Willamette’ yield. Fall spray-applied fenamiphos, fall and spring spray-applied DiTera, fall drip-applied 1,3-dichloropropene and spring shallow-incorporated Brassica carinata seed meal suppressed P. penetrans briefly (less than six months) or not at all.