Lettuce maturity detection in the visible (380-720 nm) far red (680-750 nm) and near infrared (800-1 850 nm) wavelength band E. J. BRACH, C. T. PHAN, G. POUSHINSKY, J. J. JASMIN and C. B. AUBÉ Agronomie, 2 8 (1982) 685-694 DOI: 10.1051/agro:19820801