Location: Horticultural Crops ResearchTitle: Effect of application timing of oxamyl in nonbearing raspberry for Pratylenchus penetrans management
|WALTERS, THOMAS - Washington State University Extension Service|
Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/30/2016
Publication Date: 10/1/2016
Citation: Zasada, I.A., Walters, T.W. 2016. Effect of application timing of oxamyl in nonbearing raspberry for Pratylenchus penetrans management. Journal of Nematology. 48:177-182.
Interpretive Summary: Plant-parasitic nematodes are microscopic soil worms that attack raspberry plants and cause significant loss in yield to this crop. 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 determine the best time to apply the nematicide oxamyl after planting to maximize nematode suppression. Results indicated that application timing of oxamyl in the spring was not critical to achieve nematode suppression. It was also demonstrated that this nematode management practice was more effective in fields where numbers of nematodes were high compared to fields with low numbers. These findings will help guide growers when applying oxamyl in raspberry to achieve nematode suppression and minimize unnecessary uses of this chemical.
Technical Abstract: In 2012, the Washington raspberry (Rubus idaeus) industry received a special local needs (SLN) 24(c) label to apply Vydate (active ingredient oxamyl) to non-bearing raspberry for the suppression of the root lesion nematode (RLN; Pratylenchus penetrans). This is a new use pattern of this nematicide for raspberry growers; therefore, research was conducted to identify the optimum spring application timing of oxamyl for the suppression of RLN. Three on-farm trials in each of 2012 and 2013 were established in Washington in newly planted raspberry fields on a range of varieties. Oxamyl was applied twice in April (2013 only), May, and June and these treatments were compared to each other as well as a non-treated control. Population densities of RLN were determined in the fall and spring post oxamyl applications for at least 1.5 years. Plant vigor was also evaluated in the trials. Combined results from 2012 and 2013 trials indicated that application timing in the spring was not critical. Oxamyl application reduced root RLN population densities in all 6 trials. RLN population densities in roots of oxamyl treated plants, regardless of application timing, ranged from 3 to 97 percent of densities in nontreated controls. This research also showed that the use of a non-bearing application of oxamyl will have longer term benefits, > 1 year, in fields with lower RLN population densities than in fields with higher RLN population densities. Phytotoxicity to newly planted raspberry was never observed in any of the trials. A non-bearing application of oxamyl is an important addition to current control methods used to manage RLN in raspberry in Washington.