90 CULTIVAR ANALYSIS AND PROSPECTIVE STUDIES No. 35 Olive groves and olive oil resources of Olea europaea L. in Portugal. Located at Herdade do Reguengo, within the INIAV, I.P. Elvas Innovation Centre, since 2012, the Collection brings together a representative set of native olive accessions and varieties, enabling their ex situ conservation under favourable growing conditions. The CPRO ensures the preservation of inter-varietal genetic diversity and provides a reliable repository of germplasm that supports comparative studies and the phenotypic and agronomic characterisation of the various olive materials under evaluation. This information is essential for decision-making regarding the use of materials adapted to different types of olive groves, as well as for the selection of varieties as parents for the Genetic Improvement Programme. During each annual cycle, productivity, consistency, resilience to climate change – including water and heat stress – growth habits suited to different types of olive groves, and emerging biotic pressures are some of the characteristics sought to be determined in the material held in the collection. The CPRO thus plays a strategic role in generating scientific data for knowledge and innovation in olive cultivation, enabling, in particular, the development of more sustainable and efficient cultivation practices. By integrating conservation with characterisation and evaluation, the Collection makes a decisive contribution to the protection and enhancement of the national genetic heritage and to strengthening the competitiveness and sustainability of the Portuguese olive sector. Olive grove production: balance between growth habits, fruiting and productivity The architecture of the olive tree, its leaf area and exposure to solar radiation play a decisive role in light penetration and the overall efficiency of the canopy. An adequate, well-distributed and well-lit leaf area promotes production, whilst shading or vegetative imbalance can limit fruiting and exacerbate phenomena such as fruit drop or yield alternation. In the different types of olive groves, productivity in a given climatic year depends on the balance between vegetative growth, photosynthetic capacity and production factors (e.g. water, nutrients), which together regulate production and the availability of assimilates for the reproductive organs. Olive varieties differ significantly in their vegetative growth habit, which directly influences their adaptation to olive grove types based on a higher number of plants per planted area. There are intermediate situations, and the key is to consider what will be essential for the olive tree to achieve the highest levels of production and consistency. The interaction between vegetative and reproductive processes over a biennial cycle is therefore of great importance, with photosynthesis, which takes place in the leaves, forming the basis for the production of photoassimilates, which sustain both vegetative growth and fruit development, as well as the biosynthesis of olive oil. In traditional olive groves, characterised by low planting density and fairly broad vase canopies, there is often an irregular distribution of light within the tree, reducing photosynthetic efficiency in shaded areas. In intensive olive groves, with a higher plant density and vase canopies trained through precise fruit set pruning, there is better interception of radiation and a higher proportion of active leaf area. In hedgerow olive groves, the canopy architecture is optimised to maximise lateral sun exposure, promoting high photosynthetic efficiency per unit area. The balance between leaf area and light is carefully managed to avoid excessive shading, and carbon assimilation sustains high levels of fruiting and productivity. The selection of parent trees has been carried out on the basis of agronomic, phytosanitary and technological knowledge derived from the collection and/or from comparative trials, whether or not conducted under controlled conditions. The results of the evaluation of native varieties at the CPRO confirm the high inter-varietal variability that exists across all the characteristics studied.
RkJQdWJsaXNoZXIy MTgxOTE4Nw==