Management of Meloidogyne arenaria in protected crops of Swiss chard in Uruguay.

Crop production in plastic-protected agriculture in Uruguay is limited by r oot-knot nematodes (Meloidogyn spp.). Nematode-induced losses are increasin g due to monocropping and susceptibility to infection by root-knot nematode s of the crops used. In this study we evaluated non chemical strategies for nematode control that involved integrating appropriate cultural practices and plant characteristics. The study was conducted in a macrotunnel in Tacu arembo, northern of Uruguay, which was infested with high Meloidogyne arena ria. Swiss chard was grown for nine months after the following four treatme nts were established: 1) green manure with Crotalaria spectabilis (10 kg m( -2)); 2) biofumigation with cow manure (5 kg m(-2)); 3) dazomet (400 g m(-2 )); and 4) plots previously cropped using organic methods. Non-chemical alt ernatives and organic techniques resulted in yields of Swiss chard similar to that in the chemical treatment. Our results suggest that biofumigation a nd C. spectabilis green manuring can be used to manage M. arenaria in organ ic production systems at lower cost than that associated with nematicide us e.