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With the aim to determine the effects of genotype and environment on the productivity of fruits and oil, a
field study was carried out during five consecutive seasons in three natural populations of Argania
spinosa from three geographical origin; Ait Melloul, Argana and Ait Baha in south west Morocco. The
yield corresponding to total production in fruit per tree is highly correlated to the estimated yield by the
sampling method. The regression coefficient (R²) is 0.73. Fruits productivity was varied between 0.1 Kg
(65.9 fruits) in the 1st season in Ait Baha to 94.4 kg (29298.2 fruits) during the 3rd season in Argana. For
the other components of fruit, values varied from 0.8 kg to 6.2 kg in Ait Melloul, from 0.9 kg to 7.9 kg in
Argana for almonds and kernels; and between 0.13 kg to 3.7 kg for almonds and hulls in Ait Baha.
Frequency of fruiting trees in the 1st season was higher in Argana (93.3%) and Ait Melloul (86.7%) than
in Ait Baha (50%). It was very low during the 5th season (16.6%) in Argana, in the 3th (30%) season in Ait
Baha. Oil content in almonds varied from 39.2% to 44.1%, but estimated annual yield of argan oil varied
from 0.1 kg to 2.6 kg / tree. Seasonal variations, geographical origin and genotype influence the index
qualitative of argan oil by modifying only the refractive index but not the percentage of free fatty acids.
Some genotypes were able to produce more fruits and almonds during four seasons which shows the
potential of genetic diversity present in the argan tree. To cope with water scarcity in flowering and fruit
ripening seasons in argan ecosystems, it is necessary to develop an irrigation system in orchards coupled
with a choice of “plus” genotypes to ensure high yields of fruit and oil.
Keywords: Variability, genotype, total production, regression, oil, fruit, environment, estimated yield.