|Beckman, Thomas - Tom|
Submitted to: National and Southeast Peach Convention Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/2/2002
Publication Date: 1/11/2002
Interpretive Summary: Suitable alternatives to presently registered nematicides on peach for nematode management have not been developed and need to be explored. Rootstock resistance is a nonchemical nematode management strategy needing continued investigation. However, finding a non-commercial field site to evaluate rootstocks for peach tree short life (PTSL)resistance is increasingly difficult. Determining the time needed to establish a PTSL test site on land having no history of PTSL needed to be investigated. A long-term orchard experiment was initiated in Byron, GA, to determine how long it would take to create a PTSL rootstock evaluation site on land not known to have a history of PTSL, ring nematode infestation, or peach production. Typical PTSL symptoms and tree death were first observed in the treatment plot that had peaches planted for 2 years prior to replanting the entire plot back to peaches. Results indicate that it is possible to create a PTSL test site after a 2-year preplant peach rotation and inoculation with ring nematode. These data provide useful insights into the methodology required to create a successful PTSL rootstock evaluation site. Moreover, such information will be useful to breeders and scientists working in the area of PTSL.
Technical Abstract: Peach tree short life disease complex (PTSL), induced by the ring nematode, Mesocriconema xenoplax (Mx), continues to be the primary cause of premature tree mortality in the southeastern United States. Suitable alternatives to presently registered nematicides on peach for nematode management have not been developed and need to be explored. Rootstock resistance is a nonchemical nematode management strategy needing continued investigation. However, finding a non-commercial field site to evaluate rootstocks for PTSL resistance is increasingly difficult. The purpose of this study was to determine the time needed to establish a PTSL test site on land having no history of PTSL and not infested with ring nematode. In 1994, a site not planted with peaches >80 years was identified in Byron, GA. Preplant nematode soil samples revealed no Mx. One third of the land was planted to peach and infested with Mx in spring 1994 (P2) and another third in spring 1995 (P1). The remaining third of the land received no trees or Mx and served as the control. In winter 1995, trees were removed from P1 and P2 and all treatments were replanted to peach in 1996. By 2000, PTSL tree death reached 41% in P2, 16% in P1, and 4% in the control. Nematode populations were greatest in P1 (649 Mx/100 cc soil) and P2 (300 Mx/100 cc soil) and lowest in the control (221 Mx/100 cc soil). Establishing a PTSL rootstock evaluation site on land with no history of short life and ring nematode is feasible after a 2-year-preplant peach rotation and inoculation with Mx.