Location: Fruit and Nut ResearchTitle: Occurrence and damage potential of plant-parasitic nematodes associated with blueberries (Vaccinium spp.) in Georgia and North Carolina) Author
Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: 7/1/2011
Publication Date: 12/1/2011
Citation: Jagdale, G.B., Holladay, T., Brannen, P.M., Cline, B., Nyczepir, A.P., Noe, J.P. 2011. Occurrence and damage potential of plant-parasitic nematodes associated with blueberries (Vaccinium spp.) in Georgia and North Carolina. Journal of Nematology 43:223. Interpretive Summary: Blueberries are grown in more than 30 states on over 40,500 acres in the USA. The blueberry industry in Georgia continues to grow rapidly, with substantial acreage increases on a yearly basis. Due to the age of the industry in GA, many plantings are now reaching >20 year timeframe and producers are often deciding to replant these older sites, as opposed to purchasing new land. As a result, replant disorder, a general poor growth and decline associated with plant-parasitic nematodes, is occurring. Determining the incidence of different plant-parasitic nematodes in Georgia and North Carolina as they relate to blueberry replant disease is warranted. An extensive nematode blueberry survey was conducted in GA and NC in 2010. Our results indicate that six nematode genera including ring, stunt, lance, awl, and dagger nematodes were associated with blueberry in these two states. Stubby-root nematode was found only in GA and the most frequently detected nematode was ring. In NC, we found that the awl nematode was predominantly associated with blueberry, but its pathogenicity to blueberry and relationship with blueberry replant disease are unknown, and warrant further investigation. These data provide useful insights into the incidence of different plant-parasitic nematode genera associated with blueberry replant disease and the need for developing appropriate ring nematode management strategies for blueberries grown in the Southeast.
Technical Abstract: Blueberry replant disease is an emerging threat to continued blueberry (Vaccinium spp.) production in Georgia, and possibly in the southeastern U.S. including North Carolina. Blueberry replant disease symptoms appear to be similar to those seen in peach tree short-life (PTSL) disease, which is known to be caused by the ring nematode (Mesocriconema xenoplax). After determining that ring nematodes are pathogenic to blueberry in GA, we conducted a more extensive and systematic survey of plant-parasitic nematodes (PPNs) infesting commercial blueberry orchards to determine the severity and extent of nematode replant disease in blueberry in GA and NC during the 2010 growing season. We found that six PPN genera including Mesocriconema spp., Tylenchorhynchus spp., Hoplolaimus spp., Hemicycliophora spp., Dolichodorus spp. and Xiphinema spp. were associated with blueberry in both GA and NC. Paratrichodorus spp. was found only in GA. The most frequently detected PPN in GA, Mesocriconema spp. was found in nearly half of the blueberry farms with a mean population density of 290/100 cm3 soil in those samples that contained Mesocriconema spp. In NC, Dolichodorus spp was the most frequently encountered nematode. We also found that in GA the overall mean population density recorded for ring nematodes was higher than population levels that were previously observed in the replant disease areas in the field. Our results suggest that the blueberry replant disease could become a major limitation to continued production on existing GA orchards. In NC, we found that the Dolichodorus spp. was predominantly associated with blueberry but its pathogenicity to blueberry and relationship with blueberry replant disease are unknown, and warrant further investigation.