Research Papers: Soybean Yield Losses Caused by Meloidogyne arenaria and Heterodera glycines in a Field Infested with the Two Parasites

Abstract

Linear multiple regression analyses were performed on data from six soybean [Glycine max (L) Merr.] field experiments to determine the relation between yield and soil larval populations of race 3 Heterodera glycines Ichinohe and of Meloidogyne arenaria (Neal) Chitwood. The experiments were nematicide efficacy tests conducted in 1980 in South Alabama with Bragg soybeans in a field infested with both parasites. The tests comprised treatments with fumigants (DD, EDB), systemic nematicides (aldicarb, carbofuran, oxamyl, phenamiphos) and other treatments in which combinations of anhydrous ammonia and a nitrification inhibitor (ethazole) were used to reduce nematode populations. Each experiment consisted of 14 treatments replicated eight times. A total of 672 sets of observations (yield: H. glycines: M. arenaria) were thus available for the study. Results indicated that larval numbers of M. arenaria and H. glycines were significantly and negatively related to yield but the the effect of H.