Potential of Crotalaria juncea as cover crop for cyst nematode suppression under Central Europe conditions

Abstract

Interest in the use of cover crops for soil health improvement and soil amelioration with organic matter is increasing. In addition to more general benefits, cover crops have also long been implemented for biological nematode suppression. For example for more than three decades, Heterodera schachtii has been managed by cultivating nematode-resistant brassica cover crops in Central Europe and more recently in North America. Production systems may require additional cover crop species when brassica cover crops are undesirable because of the potential increase of other soil-borne diseases, e.g., club root, that could negatively impact brassica cash crops. Alternative plant species fit for nematode suppression are needed. The tropical legume Crotalaria juncea has been successfully implemented for the suppression of Meloidogyne spp. in climates most typical to its growth requirements. This plant combines the benefits of nitrogen fixation with nematode antagonistic properties. Crotalaria juncea poses no consumption risk for ruminant animals in contrast to other species of this genus. The current study determined the C. juncea host status to five cyst nematodes, and examined the vegetation period requirements of the crop of exemplary two commercial cultivars. Both cultivars were resistant to the nematode species tested, and grew most vigorously when planted in May or June when soil temperatures were conducive for germination. This widely known nematode-suppressing plant can be grown in Central Europe. Further field studies will need to address the implementation of this plant species.