The host status of Brassicaceae to Meloidogyne and their effects as cover and biofumigant crops on root-knot nematode populations associated with potato and tomato under South African field conditions M. Daneel a, * , E. Engelbrecht b , H. Fourie b , P. Ahuja b a Agricultural Research Council -Tropical and Subtropical Crops, Private Bag X11208, Nelspruit 1200, South Africa b Unit for Environmental Sciences and Management, North-West University, Private Bag X 6001, Potchefstroom 2520, South Africa article info Article history: Received 28 February 2017 Received in revised form 1 September 2017 Accepted 3 September 2017 Available online xxx Keywords: Biofumigation Cover crops Green manure Host suitability Meloidogyne spp. abstract Cover and biofumigant crops of Brassicaceae are potential alternatives to synthetically-derived nema- ticides for managing root-knot nematode pests in various crops. The host status of Eruca sativa (cvs. Rocket Trio and Nemat), Brassica juncea (cvs Calient e and Fumigreen) and Raphanus sativus (cvs Doublet and Terranova) were determined for Meloidogyne incognita and Meloidogyne javanica in separate glass- house experiments. Additionally, the efficacy of such cover- and biofumigant crops (after incorporation of their aerial parts) was evaluated against root-knot nematode populations at two field sites (potato and tomato, respectively). All cover crops evaluated in the glasshouse showed resistance against both Meloidogyne spp., except B. juncea cv. Calient e to M. incognita. None of the Brassicaceae crops used in the potato study, however, resulted in a significant reduction of population levels of M. incognita in roots and tubers of the Brassicaceae in the follow-up potato crop. In contrast, only cv. Nemat reduced Meloidogyne spp. population densities significantly in tomato roots, while cvs Doublet, Terranova and Rocket Trio reduced population densities substantially. Plant-growth parameters, viz. plant length and mass as well as yield (fruit mass and number of fruits harvested) were significantly higher for tomato grown in plots where cvs. Doublet and Rocket Trio grew and their aerial parts incorporated. Although variable, Bras- sicaceae cvs evaluated showed potential as an alternative management strategy against root-knot nematodes. © 2017 Elsevier Ltd. All rights reserved. 1. Introduction Plant-parasitic nematodes, especially root-knot nematodes (Meloidogyne), are among the most important soil-borne pests and cause severe yield and/or quality losses to a wide range of agri- cultural crops (Jones et al., 2013). In South Africa, Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949 and Meloidogyne javanica (Treub, 1885) Chitwood, 1949 are generally regarded as the dominant species that parasitise a wide range of agri- and horti- cultural crops, particularly grains (Kleynhans et al., 1996; Riekert, 1996; Riekert and Henshaw,1998; Fourie et al., 2015). Management options for Meloidogyne are limited, mainly due to their wide host range (Jones et al., 2013). The nematode problem is further complicated since several nematicides have been with- drawn from world markets due to their toxicity and adverse im- pacts on animals, humans and the environment (EPA, 2008; Verdoorn, 2012). The use of host-plant resistance is another op- tion to combat Meloidogyne and although numerous crop cultivars with resistance are available in some countries to reduce popula- tion densities of this genus (McSorley, 2011), only a limited number has been identified in South Africa. Hence an increased interest in the exploitation and development of alternative nematode man- agement strategies is experienced. Brassicaceae crops qualify as an alternative nematode management tool and are increasingly used in agricultural production systems (Clark, 2007). The use of Bras- sicaceae crops for their cover-crop, green manure and bio- fumigation characteristics has been demonstrated as an effective, eco-friendly option to suppress Meloidogyne population densities by numerous authors as has been summarised by Fourie et al. * Corresponding author. E-mail address: mieke@arc.agric.za (M. Daneel). Contents lists available at ScienceDirect Crop Protection journal homepage: www.elsevier.com/locate/cropro http://dx.doi.org/10.1016/j.cropro.2017.09.001 0261-2194/© 2017 Elsevier Ltd. All rights reserved. Crop Protection xxx (2017) 1e9 Please cite this article in press as: Daneel, M., et al., The host status of Brassicaceae to Meloidogyne and their effects as cover and biofumigant crops on root-knot nematode populations associated with potato and tomato under South African field conditions, Crop Protection (2017), http://dx.doi.org/10.1016/j.cropro.2017.09.001