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Submitted to: Tall Fescue Information System
Publication Type: Monograph Publication Acceptance Date: 9/15/2002 Publication Date: 2/25/2005 Citation: Timper, P. 2005. Chapter 10: Nematodes. In: Frigourg, H.A., Hannaway, D.B., West, C.P., editors. Tall Fescue for the Twenty-first Century Online Monograph, Oregon State University. Available: http://forages.oregonstate.edu/is/tfis/monograph.html?pageID=24. Interpretive Summary: There are few reports of nematodes damaging tall fescue, except in sandy soils of the southeastern United States. In this region, nematodes may play a major role in limiting persistence and production of tall fescue. Nematodes tend to cause greater plant damage in sandy soils because lighter soils are conducive to nematode activity and to drought stress. The symbiotic endophyte of tall fescue confers resistance to some but not all plant-parasitic nematodes. Such determinations are made by comparing nematode numbers in tall fescue with (E+) and without the endophyte (E-). The effect of the endophyte is often dramatic, with nematode numbers less than 10% that of endophyte-free plants for root-knot and lesion nematodes. Recently, strains of the endophyte have been isolated from wild tall fescue growing in the Mediterranean region and artificially inoculated into elite tall fescue cultivars. These strains were selected because they produce low to nil levels of ergot alkaloids, yet retain many of the beneficial traits which are conferred to the plant such as drought tolerance and insect resistance. One of these new tall fescue/endophyte combinations has been commercially released under the name 'MaxQ'. The lesion nematode has been associated with poor stand performance of 'MaxQ'. Unlike the native endophyte, the nontoxic strain in 'MaxQ' does not confer resistance to this nematode. Technical Abstract: There are few reports of nematodes damaging tall fescue, except in sandy soils of the southeastern United States. In this region, nematodes may play a major role in limiting persistence and production of tall fescue. Nematodes tend to cause greater plant damage in sandy soils because lighter soils are conducive to nematode activity and to drought stress. The symbiotic endophyte Neotyphodium coenophialum of tall fescue confers resistance to some but not all plant-parasitic nematodes. Such determinations are made by comparing nematode numbers in tall fescue with (E+) and without the endophyte (E-). The effect of the endophyte is often dramatic, with nematode numbers less than 10% that of endophyte-free plants for root-knot (Meloidogyne marylandi) and lesion nematodes (Pratylenchus scribneri). Recently, strains of the endophyte have been isolated from wild tall fescue growing in the Mediterranean region and artificially inoculated into elite tall fescue cultivars. These strains were selected because they produce low to nil levels of ergot alkaloids, yet retain many of the beneficial traits which are conferred to the plant such as drought tolerance and insect resistance. One of these new tall fescue/endophyte combinations has been commercially released under the name 'MaxQ'. The lesion nematode has been associated with poor stand performance of 'Max Q'. Unlike the native endophyte, the nontoxic strain in 'MaxQ' does not confer resistance to this nematode. |
