Research collaborators from the University Institute of Research on Olive Grove and Olive Oils (INUO) at the University of Jaén – Lorenzo León from IFAPA Alameda del Obispo and Raúl de la Rosa from the Institute for Sustainable Agriculture (IAS-CSIC) – together with Concepción Muñoz Díez from the Department of Agronomy at the University of Córdoba, share their views on the key role of olive tree breeding.
Traditional olive varieties exhibit enormous genetic diversity, shaped by centuries of empirical selection. However, the development of high-density hedge systems – designed to increase productivity and facilitate mechanisation – has favoured the expansion of a small group of varieties with outstanding agronomic characteristics.
This system offers significant advantages due to its early entry into production, stable yields and the possibility of fully mechanised harvesting. In a short space of time, this has led to a marked expansion of this cultivation system in Spain and in other countries involved in the olive oil sector.
One of the most significant drawbacks of the hedge-type olive grove lay in the limited availability of varieties suited to such high planting densities. However, new varieties recently developed through breeding programmes are helping to overcome this drawback. Programmes launched in Spain in the 1990s led to the registration of the first modern varieties suited to hedge cultivation, with ‘Chiquitita’ and ‘Sikitita’ being the pioneers. Subsequently, various public and private organisations have developed new varieties such as ‘Sikitita-2’, ‘Martina’, ‘Oliana’, ‘Lecciana’, ‘Coriana’, ‘1-15’ and ‘Sultana’, which exhibit low vigour, early entry into production and high oil yield, as well as oils with good sensory profiles. However, the range of available varieties remains limited, and many more will be needed in the coming years to meet various requirements relating to plant architecture, adaptation to limiting factors, oil quality, etc. All the varieties mentioned above are descended from crosses that have always involved the ‘Arbequina’ or ‘Arbosana’ variety. This is because both varieties are closely related genetically, contributing to a dangerous genetic homogeneity in the new varieties.
At the same time, genetic improvement has also addressed other needs within the sector, such as disease resistance. To this end, new varieties such as ‘Urganova’, ‘Cástula’ and ‘Iliturgitana’ have recently been developed; these combine high resistance to verticillium wilt with good agronomic characteristics and are highly recommended for areas at high risk of this disease. This development provides an opportunity to address other needs that may arise, such as resistance to Xylella fastidiosa or the promotion of varieties with high resistance to airborne fungal diseases (repilo, soapy olive) to reduce reliance on fungicides for their control.
Looking to the future, genetic improvement will be an essential tool for tackling the many challenges that lie ahead, particularly those related to climate change. This is because rising temperatures can negatively affect various aspects of cultivation, leading to failures in flowering or a reduction in the oxidative stability of the oils produced. Conversely, reduced rainfall will increase water stress and, consequently, the need to identify and develop varieties better adapted to drought and, more generally, to new environmental conditions.
However, it should be noted that the commercial introduction of new varieties requires extensive and careful experimentation. This is because the agronomic performance of varieties depends not only on their genetic makeup, but also on the environmental conditions to which they are exposed; consequently, each variety must be tested in different environments over several years before reliable recommendations can be made. In fact, the lack of comparative trials of new varieties under standardised conditions calls for caution regarding their widespread adoption and highlights the need to establish trial plots to assess their differing performance under agroclimatic conditions. Furthermore, a promising strategy will be to promote multi-varietal plantations, combining different genotypes on a single farm to diversify the risk in the face of adversities that are not always foreseeable. It is also necessary to search, within the olive tree’s vast genetic pool, for varieties not related to ‘Arbequina’ but which are well suited to hedge cultivation.
Overall, the new varieties represent a key tool for improving and ensuring the profitability and sustainability of the crop, whilst never neglecting the preservation of the rich traditional genetic heritage, which could form the basis for tackling future challenges.
Source: Mercacei (06/05/2026)
