30 Crop Breeding and Applied Biotechnology 8: 30-38, 2008 F Mora et al. Crop Breeding and Applied Biotechnology 8: 30-38, 2008 Brazilian Society of Plant Breeding. Printed in Brazil Received 20 August 2007 Accepted 15 November 2007 INTRODUCTION Olea europaea cv. Arbequina, Picual and Frantoio have many practical applications and are very important olive cultivars for virgin or extra-virgin oil production. Picual and Arbequina are preferred in several Mediterranean regions of Spain due to their early production, high oil yield and several other agronomic advantages (Tous et al. 1998). Of the total global olive oil production of ~2.0 million tons, Picual olive oils represent 25% (Brenes et al. 2002). Spain, Italy and Greece together produce 75%, while Spain accounts for nearly half of the worlds olive harvest. Arbequina, also known as Alberquina is, according to the FAO Early performance of Early performance of Early performance of Early performance of Early performance of Olea europaea Olea europaea Olea europaea Olea europaea Olea europaea cv. cv. cv. cv. cv. Arbequina Arbequina Arbequina Arbequina Arbequina , Picual Picual Picual Picual Picual and and and and and Frantoio Frantoio Frantoio Frantoio Frantoio in the southern in the southern in the southern in the southern in the southern Atacama Desert Atacama Desert Atacama Desert Atacama Desert Atacama Desert Freddy Mora 1* , Francisco Tapia 2 , Carlos Alberto Scapim 1 , Elias Nunes Martins 1 , Ronald JosØ Barth Pinto 1 , and Antonio Ibacache 2 ABSTRACT - The cultivars Arbequina, Picual and Frantoio of Olea europaea are cultivated in several Mediterranean countries. In 1999, these cultivars were planted at three locations in the region of Coquimbo, an arid, Mediterranean-like area in Chile. A generalized linear modeling approach was used in view of the non-normal distribution of the agronomic data sets. Fruit yield (harvests of 2002-2003), precocity (2002) and tree survival (after four growing seasons) differed significantly between the cultivars. Arbequina and Picual had a positive effect on the yield. Picual was the earliest cultivar at two sites. The survival rate of Frantoio was high at the three sites (90-100%), as opposed to Picual (56-83%). The approach of Generalized Linear Models was particularly useful where the assumption of normality was not satisfied. The selection of cultivars is promising in this arid region of Chile, while the success will depend on the selection of well-adapted genotypes to a particular location. Key words: arid zones, generalized models, olive tree, quasi-likelihood. 1 Departamento de Agronomia, Centro de CiŒncias AgrÆrias, Universidade Estadual de MaringÆ (UEM), Avenida Colombo, 5790, 87.020-900, MaringÆ, PR, Brasil. * E-mail: morapoblete@gmail.com 2 Instituto de Investigaciones AgropecuÆrias (INIA), Casilla 149, Vallenar, Chile olive germplasm database, one of the most widely used Spanish cultivars for oil production (Lopes et al. 2004). In the Mediterranean basin, there are many varieties of olive trees. This region alone produces 99% and consumes 87% of the worlds olive oil (Loumou and Giourga 2003). Consequently, olive oil production and olive cultivation are often related to Mediterranean climatic conditions where hundreds of olive tree cultivars were selected over the centuries and adapted to various microclimates and soil types. The central region of Chile has a Mediterranean-like climate. In the past decade the Chilean government supported several projects (Mora et al. 2007) concerning the evaluation of plant material including Arbequina, Picual and Frantoio.