Reaction of soybean cultivars to Meloidogyne javanica in Tucumán, Argentina, 2003

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

Biological And Cultural Tests For Control Of Plant Disease

The American Phytopathological Society

Lugar: St. Paul, MN, USA; Año: 2004 p. 1 - 1

0887-2236

Thirty-eight cultivars of soybean were evaluated for their reaction to the root-knot nematode.  The experiment was conducted in a field naturally infested with root-knot nematode in La Invernada, Tucumán, Argentina.  The planting date was 12 Dec 02 and the experiment was arranged in a completely randomized design with 3 replications.  Each plot consisted of four rows 5 m long and 0.5 m apart. When plants had reached the R5 stage of development, five plants of the two central rows in each plot were rated for galling on a 0-10 scale (0=no galls, 10=maximum galls), proposed by Bridge & Page (Trop. Pest Management 26: 296-298, 1980).  Based on the gall index, cultivar reaction was determined by the following classification: 0 to 0.99, resistant (R); 1 to 2.99, moderately resistant (MR); 3 to 3.99, moderately susceptible (MS); 4 to 5.99, susceptible (S); 6 to 7.99, highly susceptible (HS); and 8 to 10, hypersusceptible (HPS).  Rainfall between Nov and Apr was 721.0 mm (average 763.8 mm), however, precipitation was less than average in Feb (30.0 mm, average 154.8 mm) and Mar (113.0 mm, average 169.4 mm).None of the cultivars evaluated was resistant to Meloidogyne javanica. Only 3 (7.9%) of the cultivars were moderately resistant, 13 (34.2%) moderately susceptible, 18 (47.4%) susceptible, and 4 (10.5%) highly susceptible.  In fields infested with M. javanica, special care needs to be taken in cultivar selection