Nonefficacy of Postplant Nematicides in Vitis vinifera Wine Grapes in Georgia, U.S.A.

Abstract

Plant parasitic nematodes (PPNs) are known to cause significant yield loss in vineyards across the world. Methods for PPN control are limited, and there is a need for development of treatments that provide long-term efficacy. Preplant fumigants provide ephemeral effects, so growers are searching for alternative, postplant nematicides to combat these pests. Two postplant nematicides, fluensulfone and spirotetramat, were evaluated for their efficacy on the three most abundant ectoparasitic PPN genera ( Helicotylenchus, Mesocriconema, Xiphinema) in a northern Georgia vineyard over a 2-year period. Nematode densities following treatment with either nematicide did not differ statistically from the untreated control. This strongly suggests that fluensulfone and spirotetramat are highly unlikely to provide useful levels of ectoparasitic PPN control on wine grapes in comparable Georgia soils.