The experiment was carried out on a private farm located in the Ziban East region on the "Deglet Nour" cultivar of the date palm (Phoenix dactylifera L.) to study a new numerical characterization technique based on the evaluation of the absorption rate red and blue rays from the leaflets of this cultivar. The leaflets of the middle crown were taken at three positions of the palm (apical, median and basal) and according to the four cardinal points: North, South, East and west and according to the faces of the leaflet (ventral and dorsal) during two seasons (autumn and spring). The results obtained show that the absorption of blue rays is greater than that of red rays for both sides of the leaflet (ventral and dorsal), according to the four cardinal points north, east, south and west and at different positions of the leaflets. On the palm of the middle crown of the date palm during two seasons (autumn and spring). The light absorption of blue and red rays is greater on the ventral side (78.24%, 69.28% respectively) than on the dorsal side (76.17%, 67.75% respectively), on the orientation south (78.57%, 71.30% respectively). The apical leaflets of the Deglet nour cultivar strongly absorb blue rays (78.53%), on the other hand, the absorption of red rays is greater in the basal and middle leaflets with (68.72%, 68,76% respectively).

date palm; characterization; leaflets; absorption of blue and red light rays; Biskra