Observações sôbre a resistência de algumas variedades de soja ao nematóide das galhas

[摘要] Soybean varieties cultivated at present in Brazil (Abura and Rio Grande), as well as some other promissing strains (455, Chosen, Georgian, Pereira Barreto, Arksoy, Acadian, etc.) have shown severe attacks by the rootknot nematodes. The study of the parasite showed that two forms are present, attacking the soybean roots, both being closely related to Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949. Variety N 46-2652, considered to be resistent in the Southern part of the United States, proved to be susceptible to the mentioned nematodes, according to results of two pot test, discussed in this paper. Palmeto, La 41-1219, N 45-3799 and Otootan varieties were considered resistent to these nematodes, judged by the results of one field trial here reported. The resistence of varieties Palmeto and La 41-1219 was also confirmed by two pot experiments in which artificial infestation by nematodes was produced.