Submitted to: Methyl Bromide Alternatives and Emissions Research Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: August 23, 2005
Publication Date: October 31, 2005
Citation: Nyczepir, A.P., Beckman, T.G., Reighard, G.L. 2005. Evaluation of Guardian peach rootstock to the peach and pecan root-knot nematodes. Proceedings of the Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions. San Diego, CA. Oct. 31-Nov. 5, 2005. p. 108-1-2. Interpretive Summary: Root-knot nematodes are an important pest of peach in the U.S. and other parts of the world. Four major Meloidogyne spp. have been reported to cause damage to stone fruits throughout the world, but Meloidogyne incognita and M. javanica are the predominant species found on peach and plum. In previous short-term greenhouse studies, commercial sources of Guardian peach rootstock were effective in suppressing the reproduction of M. incognita and M. javanica 110 days after inoculation. However, additional long-term research is needed to elucidate the effect different root-knot nematode species have on growth parameters of Guardian and other advanced Prunus germplasm. A field microplot and greenhouse study was initiated to examine the susceptibility of an advance line of Guardian rootstock (SC 3-17-7) to M. floridensis (Peach root-knot nematode) and M. partityla (Pecan root-knot nematode), respectively. Results indicate that M. floridensis did not suppress tree growth of SC 3-17-7 as compared to the uninoculated control. In the greenhouse study, results indicate that M. partityla did not reproduce nor produce root galls on SC- 3-17-7. These data provide useful insights into the potential recommendation of Guardian rootstock in peach orchards infested with certain root-knot nematode species. Additionally, these data illustrate that SC 3-17-7 is resistant/tolerant to M. floridensis and M. partityla.
Technical Abstract: An advance line of GuardianTM (i.e., SC 3-17-7) peach rootstock was evaluated for susceptibility and (or) growth response to Meloidogyne floridensis (Peach root-knot nematode; FL-peach isolate) and M. partityla (Pecan root-knot nematode; GA-pecan isolate) in field microplot or greenhouse studies, respectively. Results indicate that after 23 months, M. floridensis did not suppress tree growth of SC 3-17-7, Nemaguard, or Flordaguard rootstocks as compared to the uninoculated control. Meloidogyne floridensis reproduced on all 3 rootstocks, with greatest number of eggs per gram dry root being produced on Guardian and Nemaguard. In the greenhouse study, M. partityla did not reproduce nor produce root galls in 4 months after inoculation on any of the peach rootstocks tested (i.e., SC 3-17-7, Lovell, and Nemaguard) as compared to the known susceptible ‘Curtis’ pecan control.