We will present our results obtained in the framework of the recent European project Legume Futures. We tested the tropical non-crop legume Crotalaria juncea for biological control of phytoparasitic root-knot nematode populations and green manure effect in greenhouse tunnel vegetable production in Mediterranean conditions. Results show that C. juncea (1) grows rapidly in Mediterranean conditions producing a significant biomass (2) has a very positive green manure effect on lettuce production in both sites and within two successive campaigns (3) significantly reduce on lettuce gall scores. Mycorrhization index and rate of C. juncea are significantly higher than that of Ray-grass used as a reference mycorrhizogenous plant. Plants nodulate and natural abundance in 15N show that may be equivalent to about 50 Kg of fixed nitrogen per ha in 3 months. (Texte intégral)