عنوان مقاله [English]
Introduction According to statistics presented by FAO in 2011, the world area under olive cultivation has been estimated about 9 million and six hundred thousand hectares from which Iran shares approximately 103 thousand hectares. Tarom region in Zanjan province is one of the important olive cultivation in which 12600 hectare has been devoted to olive planting. A growing trend could be seen if the cultivation area regarding the fertile and non- fertile olive orchards along with amount of production were compared during the last decades which may be attributed mainly to favorable climatic condition for olive cultivation in the region. Temperature as the most important environmental factor affects flowering and fruiting of olive trees. Temperatures that stimulate olive fruiting, and sub-zero temperatures which cause damage to olive tree or fruit yielding are of great importance in determining the adaptability of olive trees. Regarding the quality of olive oil, fruit characters such as: cultivar, ripening and climatic conditions are considered as main characters too. To determine the adaptable cultivars for any region and microclimates many experiments have been carried out worldwide. In Iran, Zard and Roghany local olive cultivars selected for northern parts of Iran with the most area under cultivation in Rudbar and Tarom regions but the Dezful cultivar has been released for southern regions of the country. This study was carried at Tarom Olive Research Station, Zanjan, Iran and aimed to evaluate the vegetative and reproductive traits of some domestic and foreign olive cultivars and to determine the adaptability of them to the studied area.
Materials and Methods At the beginning of the study, age of the olive trees varied between 4 to 6 years and all the trees were in the reproductive phase. Plantation system was also 8 × 8 meters with trickle irrigation systems. The cultivars were: Amigdalolia, Arbequina, Abusatl, Bladi, Picual, Roghany, Zard, Koroneiki, Konservolia, Leccino, Mary, Mastoidis, Manzanilla, and Mission. The experiment was conducted based on a RCBD layout with three replications considering four trees for each plot. Vegetative characters (tree vigor, growth habit and crown density), flower traits (number of flower per inflorescence, number of inflorescence per shoot, perfect flower) and fruit characters (fruit weight, length and diameter of fruit, stone weight, flesh to stone ratio, oil percent in dry fruit weight and yield per hectare) as well as susceptibility of crown trees to wind and susceptibility to cold, along with the cumulative yield of 5-year were measured. For statistical analysis the SAS software was used and means comparisons were performed using Duncan Multiple Range Test.
Results and Discussion: Results showed that among evaluated cultivars, the number of flowers per inflorescence in most cultivars except Leccino, Baladiand Koroneiki were the same level. Manzanillaand Mission had the highestflowers per inflorescence but Leccino and Baladi had the lowest number of flowers per inflorescence. Arbequina, Koroneiki, Baladi, Zard, Konservolia, PicualandRoghany in comparison with other cultivars had high perfect flowers. Konservolia, Zard, Koroneiki, Arbequinaand Abusatl had the highest yield. Theyield of these cultivars was 4265, 3498, 3104, 2625, 2273and2101kg per hectare, respectively. The cumulative yield of abovementioned cultivars in5-year were 22472, 17490, 15520, 13125, 11365and10505 Kg/ha, respectively. Amigdalolia, Konservolia, Baladiand Mastoidis cultivars had the highest oil content in dry matter basis. Also Mari, Koroneiki and Arbequina cultivars had the highest oil content. Fruit weight of Amigdalolia, Abusatl and Konservolia cultivars were more than 8 gr. More over Picual, Zard, Mission and Manzanilla cultivars fruit weight were between 5 and 6 gr. Konservolia, Abusatl, Manzanilla, Amygdalolia, Picual and Mastoidis had the highest flesh to stone ratio. The flesh to stone ratio of these cultivars was 10.09, 9.35, 9.04, 8.16, 7.45 and 7.05 respectively.
Conclusion: Konservolia as a double purpose cultivar was the first olive cultivar choice of this research. Konservolia as compared with other cultivars had the highest yield. In addition,it is reported that this cultivar tolerated cold temperatures (low temperatures)during years of 2006 and 2007.Konservolia with large fruit and a high ratio of flesh to stone can be a substitute for the Zard olive cultivars in Tarom area. Zard, Koroneiki and Arbequina were the other selected of these studies. Zard is a native cultivar. Now, this cultivar is the first priority of Tarom region, because is a double purpose cultivar. Moreover studies showed that Zard in comparison with other native cultivars had high oil quality.