Investigation on semi-rain fed plantation by varieties of Olives in Mehran, Ilam province

Major parts of Ilam province in south regions, Mehran and Dehloran, have some poor plain with arid and hot climate. Considering the circumstances, the introduction and afforestation by use of multi-purpose and resistance to dehydration in plants, such as olive trees, can have an important role in soil conservation and the process of province and the country. In this study the aim was to identify the most adaptive and resistant varieties of olive (Olea europaea L.) to semi-rainfed (low irrigation) condition of warm climate (parts of Ilam province). Three varieties of Olive (Dezfuli, Roughani and Zard) as multipurpose species, under a trial randomized complete blocks design with four replications, 5 x 5 m. spacing, limited irrigation operation (only first year) was used in 2002 in Mohsenab station, Mehran township. Phenology, growth and survival of the seedlings were recorded annually at the end of dry period and analyzed statistically. The results at the end of the trial (2011) showed that there is significant difference between provenances so that the most resistant olive variety is Roughani with survival of 55 %, whereas the two other varieties have the survival of 41.6% for Zard and 27.5 % for Dezfuli. The means for height, crown diameter and collar diameter of olive varieties tested did not show any significant difference. The mean height, crown cover diameter and collar diameter of the olives were 298, 235 and 18 cm, respectively. Roughani in low irrigation conditions of this study, with growth in height (23 cm per year) and canopy growth (20 cm per year) is introduced as higher variety in this study. To achieve better growth performance for Olive in these areas at least once or twice irrigation during the dry season (each about 50 liters of water per tree) would be necessary.