Host suitability of cover crops for Meloidogyne javanica and M. incognita

Management of plant-parasitic nematodes in no-tillage systems relies on knowledge of the species, their abundance and their host range in a certain cropping area. Crop rotation is one of the most efficient techniques in the control of plant-parasitic nematodes; thus, the identification of non-host plant species is essential. Therefore, the aim of this study was to evaluate the host suitability of different cover crops used in crop rotations to control two of the most devastating plant-parasitic nematodes in the Brazilian central region, Meloidogyne javanica and M. incognita. Two experiments were conducted in a completely randomised design under glasshouse conditions. In the M. incognita experiment, seven treatments (cover crops) were evaluated: Crotalaria juncea (sunn hemp; CJ), Stylosanthes humilis (Townsville stylo; TS), Pennisetum glaucum (millet; M), Triticum aestivum (wheat; W), Mucuna aterrima (black mucuna, BM), Glycine max (soybean treated with nematicide (fluensulfona) (SN) and soybean without nematicide (SwN)). In the M. javanica experiment, nine treatments were evaluated: Cajanus cajan (pigeon pea). Brassica napus (canola). B. nigra (mustard), CJ. M. W. BM. SN and SwN. The evaluations were performed 60 days after inoculation, when eggs and juveniles were present in the plant roots and soil, and the nematode reproduction factors (RF) were determined. The results indicated that CJ, M and BM were effective in controlling M. javanica and M. incognita. The SwN and even SN resulted in high RF and were not effective in the control of M. javanica and M. incognita.