HOST SUITABILITY OF FORAGE GRASSES AND LEGUMES FOR ROOT-LESION NEMATODE PRATYLENCHUS PENETRANS

Pratylenchus penetrans reduces the productivity of many forage crops in northern USA and eastern Canada. Our objective was to determine the host suitability of forage grasses and legumes for P. penetrans in greenhouse, growth chamber, and field environments. In the greenhouse and growth chamber environments, P. penetrans reproduced on all forage grasses (17) and legumes (12). Both the legumes and grasses varied (P < 0.05) for numbers of nematodes and eggs in the roots. The most suitable hosts included kura clover (Trifolium ambiguum M. Bieb.), alsike clover (Trifolium hybridum L.), white clover (Trifolium repens L.), oat (Avena sativa L.), and rye (Secale cereale L.). The least suitable hosts included pearl millet [Pennisetum glaucum (L.) R. Br.], tall fescue (Festuca arundinacea Schreber), perennial ryegrass (Lolium perenne L.), forage sorghum [Sorghum bicolor CL.) Moench], sudangrass (Sorghum sudanense Pers.), sudex (Sorghum sudanense x S. bicolor), sweetclover (Melilotus alba Desr.), crownvetch (Coronilla varia L.), and MNGRN-16 alfalfa (Medicago sativa L.). Twelve legumes and 9 grasses were transplanted into a held infested with P. penetrans and one-half the plants were treated with carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranol methylcarbamate). Pratylenchus penetrans reproduced on all entries. Numbers of nematodes per gram fresh root of entries in the greenhouse-growth chamber and field tests were correlated for both the control (r = 0.60, P < 0.05) and carbofuran treatment (r = 0.48, P < 0.05). We concluded that many forage species are hosts for P. penetrans, but a few legumes and grasses are poor hosts and may be useful in forage rotations to reduce nematode populations.