Influence of photon flux density and fluctuation on the nitrogen fixing Glycine max (L Merr)-Bradyrhizobium japonicum symbiosis in a controlled environment JJ Drevon, JP Gaudillère, JP Bernoud, F. Jardinet and M. EvrardAgronomie, 11 3 (1991) 193-199DOI: https://doi.org/10.1051/agro:19910306