Submitted to: International Conference on Methyl Bromide Alternatives and Emissions Reductions
Publication Type: Proceedings
Publication Acceptance Date: 8/30/2006
Publication Date: 11/6/2006
Citation: Nyczepir, A.P. 2006. Evaluation of tall fescue for resistance to root-knot nematode in peach. Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions Proceedings. 136:1-2. 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 South Carolina peach orchards, M. incognita and M. javanica were found in 95% and 5% of orchards sampled, respectively. In the southeastern United States, preplant fumigation in combination with a nematode resistant rootstock is recommended for increased tree longevity and maximum protection against root-knot nematodes. However, in recent years growers have been faced with economic hardships which made it difficult to afford the costs associated with preplant fumigation and (or) not being able to get the land fumigated at the recommended time of year due to a conflict with managing other crops. It is also worth noting that at a recent growers meeting in 2006, a prominent Georgia peach grower inquired about the availability of using a preplant ground cover in place of preplant fumigation to control root-knot nematode. Finding an alternative groundcover rotation to preplant chemical control of root-knot nematode is warranted. A greenhouse study was initiated to examine the susceptibility of tall fescue to M. incognita (GA-peach isolate). Results indicate that M. incognita did not reproduce nor produce root galls on tall fescue as compared to Lovell peach (i.e., root-knot nematode susceptible host). These data provide useful insights into the potential use of tall fescue rotation as an alternative to preplant chemical control of root-knot nematode prior to peach tree establishment.
Technical Abstract: Host susceptibility of endophyte-present (E+) and endophyte-absent (E-) tall fescue grass to the Southern root-knot nematode, Meloidogyne incognita (GA-peach isolate) were evaluated under greenhouse conditions. Tall fescue lines evaluated included, 1) Jesup EI (E+, wild-type endophyte present), 2) Jesup EF (E-, no endophyte present), 3) Max-Q (E+, but non-ergot producing endophyte), and 4) GA-5 (E+). Additionally, Lovell peach (i.e., root-knot nematode susceptible) was included as the reference control. The study was terminated 123 days after inoculation with 3,000 eggs per pot. The study was repeated one time. In both fescue evaluation tests, Lovell peach supported greater (P < 0.05)) reproduction of M. incognita (i.e., 8,787 and 25,449 eggs per gram dry root, respectively) than on Jesup EI (i.e., 0 & 0 eggs per gram dry root, respectively), Jesup EF (0, 15), Max-Q (0, 0), and GA-5 (0, 0) tall fescue plant treatments. Results indicate that all tall fescue lines tested were either poor or nonhosts for M. incognita and that the presence of the endophyte does not appear to effect nematode reproduction.