Sammanfattning

Phytophthora root rot (PRR) disease afflicts significant economic losses to the Fraser fir Christmas tree industry. In previous surveys conducted in 1972 and from 1997 to 1998 in North Carolina, the incidence of PRR was approximate to 9.5% with Phytophthora cinnamomi identified as the predominant causal species isolated from infected roots of Fraser fir. Due to increased use of out-of-state planting stock since 2000, we suspected increased diversity of Phytophthora species. During 2014, we surveyed Fraser fir Christmas tree plantations in the Southern Appalachians of North Carolina, Tennessee and Virginia to determine the occurrence of pathogenic root-rotting species of Phytophthora. A weighted sampling strategy based on Christmas tree acreage was deployed to collect symptomatic Fraser fir roots from 103 commercial production fields in 14 counties. Six species of Phytophthora were isolated from infected roots sampled from 82 sites in 13 counties. Phytophthora cinnamomi, P. cryptogea and P. pini represented 70.3%, 23.1% and 1.1% of the 91 isolates. Phytophthora citrophthora, P. europaea and P. sansomeana accounted for the remaining 5.5% of the isolates and have not been identified in previously published Fraser fir surveys conducted in the region. The pathogenicity of P. citrophthora on Fraser fir was confirmed based on completion of Koch's postulates.

Nyckelord

Abies fraseri; North Carolina; Phytophthora cinnamomi; root rot; survey

Publicerad i

Scandinavian Journal of Forest Research
2017, Volym: 32, nummer: 5, sidor: 412-420
Utgivare: TAYLOR & FRANCIS AS

SLU författare

• Rönnberg, Jonas

  • Institutionen för sydsvensk skogsvetenskap, Sveriges lantbruksuniversitet
    

Associerade SLU-program

SLU Nätverk växtskydd


UKÄ forskningsämne

Skogsvetenskap


Publikationens identifierare

DOI: https://doi.org/10.1080/02827581.2016.1265144

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/83512