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

Pratylenchus penetrans reduces the productivity of many forage crops i n northern USA and eastern Canada. Our objective was to determine the host suitability of forage grasses and legumes for P. penetrans in gre enhouse, growth chamber, and field environments. In the greenhouse and growth chamber environments, P. penetrans reproduced on all forage gr asses (17) and legumes (12). Both the legumes and grasses varied (P < 0.05) for numbers of nematodes and eggs in the roots. The most suitabl e hosts included kura clover (Trifolium ambiguum M. Bieb.), alsike clo ver (Trifolium hybridum L.), white clover (Trifolium repens L.), oat ( Avena sativa L.), and rye (Secale cereale L.). The least suitable host s 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 su danense Pers.), sudex (Sorghum sudanense x S. bicolor), sweetclover (M elilotus alba Desr.), crownvetch (Coronilla varia L.), and MNGRN-16 al falfa (Medicago sativa L.). Twelve legumes and 9 grasses were transpla nted into a held infested with P. penetrans and one-half the plants we re treated with carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranol me thylcarbamate). Pratylenchus penetrans reproduced on all entries. Numb ers of nematodes per gram fresh root of entries in the greenhouse-grow th 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 concl uded that many forage species are hosts for P. penetrans, but a few le gumes and grasses are poor hosts and may be useful in forage rotations to reduce nematode populations.