RESUMEN
Surveys from 1986 to 1988 identified 22 phytoparasitic nematode species in Arkansas cotton fields. Meloidogyne spp. was found in ca. 15% of the fields sampled. Of these samples ca. 33% were found to have a population density of 106/100 cm(3) of soil or more. Rotylenchulus reniformis was found in high numbers (5,000 +/100 cm(3) of soil) in 1% of the fields sampled in 1988. Heterodera glycines was found in ca. 22% of the samples, presumably because of past cropping to soybean. Other common species found were Pratylenchus alleni, P. brachyurus, P. scribneri, Tylenchorhynchus ewingi, T. goffarti, Quinisulcius acutus, Helicotylenchus dihystera, H. pseudorobustus, Hoplolaimus magnistylus, Paratrichodorus minor, and Xiphinema americanum. Paratylenchus spp. juveniles were found in ca. 10% of the samples; adults of P. projectus and P. tenuicaudatus were found in ca. 1% of the samples. Other species found only rarely were Pratylenchus zeae, Merlinius brevidens, T. martini, Helicotylenchus multicinctus, Scutellonema brachyurum, and X. chambersi.
RESUMEN
In Arkansas wheat is commonly grown either in rotation or double cropped with soybean. Surveys from 1986 to 1988 identified 18 phytoparasitic nematode species in Arkansas wheat fields. The frequency of occurrence, as a percentage of the total number of samples (199), for the following nematodes was Heterodera glycines 43%, Quinisulcius acutus 40%, Pratylenchus scribneri 37%, Helicotylenchus pseudorobustus 15 %, Xiphinema americanum 14%, Paratylenchus tenuicaudatus 13 %, Pratylenchus alleni 10%, Merlinius brevidens 8%, Tylenchorhynchus ewingi 7%, Paratrichodorus minor 5%, T. martini 4%, and Hoplolaimus magnistyIus, Paratylenchus projectus, and juveniles of Meloidogyne spp. 2%. Helicotylenchus dihystera, Paratylenchus elachistus, and Tylenchorhynchus claytoni were each found in one wheat field.
RESUMEN
Results of surveys from 1978 to 1986 to estimate and identify nematodes in Arkansas soybean fields are presented. The seven most common nematode species in the fields were Heterodera glycines, Quinisulcius acutus, Pratylenchus scribneri, P. alleni, Helicotylenchus pseudorobustus, Tylenchorhynchus ewingi, and Xiphinema americanum. Other nematodes identified from these fields were Pratylenchus brachyurus, P. vulnus, P. zeae, Tylenchorhynchus canalis, T. goffarti, T. martini, Helicotylenchus dihystera, Scutellonema bradys, Xiphinema chambersi, X. rivesi, Hoplolaimus galeatus, H. magnistylus, Paratrichodorus minor (P. christiei), Paratylenchus projectus, P. tenuicaudatus, Criconemella macrodora, C. ornata, and Meiodorus hollisi.