Characterization of some Introduced Varieties of European Olive Under Rainfed Conditions and Supplemental Irrigation at Jellin Research Station (Daraa, Syria)

This study was carried out during the years 2010 and 2011 to characterize some varieties of European Olive; Konservolia and Amigdalollia (Greece); Picholine and Tanche (France), Frantoio (Italy) and Belladi Spain (Spain). We aimed to assess those varieties under rainfed and supplementary irrigation at Jellin Research Station (Daraa/Syria).Different traits were scored such as: average of annual vegetative growth, characteristics of leaves (length, width and leaf surface), fruit (length, width, weight and size), average of flower number per cluster, fertilization and oil ratio in contrast to the dry weight. Significant differences were detected between the supplemental irrigation in contrast to rainfed treatment for the majority of the traits.The proportion of fruit set was 7.22% for the rainfed culture and increased to 16.97% for the supplemental irrigation. Based on the dry weight for all of the varieties, we reported an oil percentage estimated at 30.88% and 45.64% for rainfed and irrigated treatments, respectively. On the other hand, an adverse values were reported on the basis of the wet weight; the oil content was estimated at 20.61% under the rainfed conditions and 16.95% under the irrigation treatment. This result can be due to the accumulation of water, oil and other ingredients in vacuoles.The drought tolerance parameters (chlorophyll A, chlorophyll B, relative water content, leaves water content, ratio of leaf dry weight, glucose, proline) were used to draw the relationship tree between the varieties. The varieties were divided into two clusters, the first combined four of highest drought tolerance varieties (Konservolia, Picholine, Frantoio and Belladi Spain) with 10.863 distance in between. While two varieties, Amigdalollia and Tanche, were in the second cluster, with 4.548 distance in between. Furthermore, the second cluster is far from the first one with the distance 18.144. Hence, these varieties, with high drought tolerance ability, would be recommended for the cultivation in dry areas prevailed in some Arab countries.