Presence of Phytophthora species in Swedish Christmas tree plantations

Quantitative resistance differences between and within natural populations of Solanum chilense against the oomycete pathogen Phytophthora infestans

“…In case of Norway spruce, Picea abies , and Nordmann fir, Abies nordmanniana , in Swedish Christmas tree farms, which currently are not under threat by Phytophthora , it has been shown that after inoculation with different isolates of Phytophthora sp. (isolated from water and soil samples from the same region), all the seedlings of these plants showed a basal level of resistance under laboratory conditions (Pettersson et al, 2019). A study by Redondo et al.…”

Survey of the Phytophthora species diversity revealsP. abietivoraas a potential Phytophthora root rot pathogen in Québec Christmas tree plantations

“…More than 20 Phytophthora species have been associated with more than 20 different species of true firs (Farr 2022), with at least 12 Phytophthora species known to induce PRR (McKeever and Chastagner 2016). Since the mid-2000s, data available for European countries overlap with what is found in the US (Pettersson et al 2019; Shafizadeh and Kavanagh 2005; Talgø et al 2006; Talgø et al 2007; Talgø et al 2017), suggesting that either the association between these Phytophthora species and firs have been longstanding or that, as for other Phytophthora species, worldwide plant trade has contributed to their global dissemination (Bienapfl and Balci 2014; Brasier 2013; Jung et al 2016). While the information currently available connects Phytophthora species to PRR symptomatic trees, few studies have shown their pathogenic potential with Koch’s postulates (Frampton and Benson 2012; Hamm and Hansen 1982; Hoover and Bates 2013; McKeever and Chastagner 2016).…”

“…While the information currently available connects Phytophthora species to PRR symptomatic trees, few studies have shown their pathogenic potential with Koch’s postulates (Frampton and Benson 2012; Hamm and Hansen 1982; Hoover and Bates 2013; McKeever and Chastagner 2016). Moreover, when Koch postulate are tested, the experiments are usually performed by injuring the tree and directly putting the pathogen at the wounded site (Li et al 2019; McKeever and Chastagner 2016; Pettersson et al 2019; Quesada-Ocampo et al 2009), which does not capture all infection patterns (Hardham 2001; Judelson and Blanco 2005).…”

What’s under the Christmas Tree? A Soil Sulfur Amendment Lowers Soil pH and Alters Fir Tree Rhizosphere Bacterial and Eukaryotic Communities, Their Interactions, and Functional Traits

“…Each year, approximately 33 million to 36 million Christmas trees are produced in North America, with an additional 50 million to 60 million grown in Europe ( 1 ). A problem for Christmas tree producers is that fir trees are susceptible to root rot diseases caused by Phytophthora species ( 2 , 3 ). One potential method to control root rot organisms is to alter the soil pH.…”