Nematodes associated with soybean in Tucumán, Argentina

CORONEL, N; PLOPER, L.D.; JALDO, H; GÁLVEZ, M R

Foz do Iguassú

Conferencia; VII World Soybean Research Conference (VII WSRC).; 2004

Embrapa SOJA y WSRC Continuing Committee

Soybean is one of the most economically important crops in Tucumán, Argentina and is grown on 243.390 hectares in the province. Nematodes are among the pests associated with the crop. The presence of soybean cyst nematode (Heterodera glycines) in the region was confirmed in 1998. Root-knot nematodes, Meloidogyne spp., have also been reported in the region. The incidence and predominance of other plant-parasitic nematodes are little known. In order to document new infestations of Heterodera glycines and Meloidogyne spp. and the presence of other nematodes, a nematological survey was conducted during the 2002/2003 growing season.  Soybean fields were sampled using direct soil sampling, which consisted of taking 10 subsamples from each hectare and combining those to make a compound sample. Selection criteria for the sampling were the presence of lighter sandy soils and the occurrence of poor crop growth, or chlorotic or withered plants.  In the laboratory, 81 soil samples were processed utilizing the flotation and the flotation-centrifugation techniques.  H. glycines was found in 19% of the soil samples, with population levels between 0.5 and 25 cysts per 100 cm3 of soil.  The root-knot-nematode, Meloidogyne sp. was detected in 62% of soil samples with population levels between 0.25 and 254 second-stage juveniles per 100 cm3 of soil. The remaining nematodes identified from the soil samples were: Helicotylenchus, Pratylenchus, Tylenchus, Tylenchorhynchus, Trichodorus, Macroposthonia, Xiphinema and Scutellonema.