Use of Sunn hemp, Crotalaria juncea, as a green manure for the management of plant-parasitic nematodes of carrot in organic soil
Organic soils are an important resource for vegetable crops. However, these crops are very demanding in terms of pest control, fertilization and tillage. Combined with organic soil subsidence, current practices threaten the sustainability of this resource. In this study, we test the potential of Sunn hemp (Crotalaria juncea) as a green manure to control populations of plant-parasitic nematodes and as a carbon input to the soil. Incorporating Sunn hemp resulted in a ten-fold reduction in populations of the northern root-knot nematode (Meloidogyne hapla) and a significant increase in carrot yields the following year. However, no significant effect was observed on the root-lesion nematode, Pratylenchus penetrans.