DIVERSITE DES CULTIVARS DU PALMIER DATTIER : UN ATOUT EN FAVEUR DU DEVELOPPEMENT DU SECTEUR PHOENICICOLE A N’GOUSSA

Abstract

The objective of this study is to assess, through indicators, the diversity of date palm (Phoenix dactylifera) cultivars in the N’Goussa palm grove (Ouargla, northeastern Algerian Sahara). The aim is to estimate their age, to study their distribution and to decide on the cultivars identified by using the IUCN classification in order to assess the risk of erosion. This will help to consider actions in favor of a possible rehabilitation and restoration of the declining heritage and to provide public authorities and decision-makers; with an asset for an informed management of this resource. The survey took place during the date harvest period (between October 2019 and January 2020) using an adapted survey form, administered in a systematic way for the 41 farms spread over 8 selected sites corresponding to the different boreholes in the area. This made it possible to identify 2917 plants divided into 24 date palm cultivars of varying ages (between 14 and 80 years). The relative abundance of cultivars shows a modest diversity and a general trend of two cultivars Deglet Noor (44%) then Ghars (38%), while all the remaining 22 cultivars represent only 18%. Thus, the index of frequency of occurrence reveals five classes of cultivars (accidental: 33.3%; incidental: 25%; constant: 16.7%; regular: 8.3% and ubiquitous: 8.3%) for a sampling quality considered good (0.4). The threat status shows that 22 cultivars among the 24 identified are classified as threatened with extinction, i.e. 91.7%, of which 79.2% are critically endangered and 12.5% endangered. Urgent measures must be taken in favor of the least abundant and most vulnerable cultivars for their preservation.