Effect of rotation crops on hatch, viability and development of Heterodera glycines

Abstract

Rotation with non-host crops can be an effective method for reducing soybean cyst nematode (Heterodera glycines) populations in soybean cropping systems. Sunn hemp, Illinois bundleflower, oilseed rape, perennial ryegrass, red clover, corn and H. glycines-susceptible soybean were compared for their effects on H. glycines hatch, viability and development in laboratory and glasshouse experiments. In the laboratory experiments, root exudates in soil leachates, extracts from fresh plant tissues, and extracts from residues of sunn hemp, red clover and soybean stimulated hatch of second-stage juveniles (J2) of H. glycines. All crops appeared to contain hatch inhibitors as well. There was no apparent effect of the root exudates and extracts from any of the crops on egg viability in vitro. When the H. glycines J2 were exposed to root exudates and extracts for 72 h, only the extracts of fresh plants and plant residue from sunn hemp, red clover and soybean, and the extract of plant residue from oilseed rape reduced viability of J2. In glasshouse experiments, residues of all crops, except Illinois bundleflower, reduced egg population density, with sunn hemp providing the greatest reduction. Residues of sunn hemp, red clover, and perennial ryegrass added to soil reduced the reproduction factor, suggesting the residues not only reduced egg population density but also reduced nematode infectivity. While all crops allowed penetration by J2, minimal development (to third-or fourth-stage juveniles only) occurred only in sunn hemp, red clover, oilseed rape and Illinois bundleflower, and full development occurred only in soybean. The results suggest that sunn hemp and red clover were the most effective rotation crops for managing H. glycines, and that stimulating hatch of H. glycines J2 was the main mechanism involved in reducing the H. glycines population density.

Práticas culturais na entressafra da soja para o controle de Pratylenchus brachyurus

“…Estes resultados corroboram os obtidos em estudos de casa de vegetação sobre a reação destas espécies ao nematoide (Inomoto et (Warnke et al, 2008;Curto et al, 2015). Além desse mecanismo, as plantas de crotalária acumulam metabólitos secundários com ação nematicida nas raízes, parte aérea e sementes, como o alcaloide pirrolizidínico denominado monocrotalina (Wang et al, 2002;Colegate et al, 2012).…”

“…Todavia, o estímulo à atividade de organismos nematófagos (Wang et al, 2002) e a liberação substâncias nematicidas (Colegate et al, 2012), a partir da decomposição da fitomassa da parte aérea de C. juncea, pode contribuir para o aumento da mortalidade do nematoide em condições de campo, em comparação aos ensaios de casa de vegetação. Neste sentido, reduções da população de nematoides fitófagos, após a aplicação de biomassa da parte aérea de C. juncea, foram observadas por Garrido et al (2008) e Warnke et al (2008).…”

Yield and Economic Effectiveness of Soybean Grown Under Different Cropping Systems

“…This promotes obtaining higher seed yields compared to those found in monoculture cropping of soybean. In the opinion of Chen et al (2008) and Leandro and Asmus (2015), lower yields in soybean monoculture can be attributed, among others, to damage caused by the soybean cyst nematode (SCN) (Heterodera glycines) and the reniform nematode (Rotylenchulus reniformis). Hamid et al (2017), in turn, think that long-term soybean monoculture may contribute to suppression of SCN cysts through the assembly of bacterial and fungal communities in the rhizosphere.…”

Determining the Role of Plant–Parasitic Nematodes in the Corn–Soybean Crop Rotation Yield Effect Using Nematicide Application: I. Corn

“…However, soybean benefi ts from crop rotation despite fi xing its own N Meese et al, 1991;Porter et al, 1997;Wilhelm and Wortmann, 2004;Salvagiotti et al, 2008). Additionally, a number of studies, including ones at the site of the present study, have established that the rotation eff ect occurs even when suffi cient nutrients are supplied by fertilizers Meese et al, 1991;Porter et al, 1997;Howard et al, 1998;Wilhelm and Wortmann, 2004).…”