Thermal requirements for the ripening of date palms in Biskra (South-East Algeria)

The monitoring of phenological stages of date palm and air temperature in Biskra, which is a potential date palm cultivation region in Algeria, during the years 2018 and 2019, has recorded a temporal advancement of the phenological cycle of this plant. This advancement has influenced the dates of harvest, which have become earlier. For their part, the thermal accumulations recorded during the fruiting of the date palm, have experienced an upward trend; they are 3689 to 5141°C, for a base temperature of 10°C. These accumulations are higher, if 7°C is considered as vegetation zero (5170-6835°C). In contrast, the flowering zero recorded in the study area is around 13°C.