Reproductive Biology of Olive Trees (Arbequina cultivar) at the Northern Limit of Their Distribution Areas

In recent years, North-western Spain has experienced an increase in the cultivated area of olive trees. The main propitious areas for groves are Miño and Sil basins, as a consequence their Oceanic climate with Mediterranean influence. objective this study is to determine characteristics reproductive biology, phenological aerobiological behaviour trees most northerly new plantation Iberian Peninsula. was carried out grove growing Olea europaea L. cv. ‘Arbequina’ located Quiroga (Lugo) from 2016 2018. observations were based upon growth stages following Biologische Bundesanstalt Bundessortenamt Chemical industry (BBCH) scale. To predict onset flowering, thermal time model used order quantify chill requirements, degree-days applied heat requirement. production, viability germination rates pollen evaluated samples selected nine individual survey. conducted by means Hirst-type trap centre grove. vegetative period tree lasted average 259 days. important stage 6 (flowering) shortest stage. An 704 Chilling Hours (CH) threshold 2.5 °C required overcome chilling period, 1139 Growing Degree Days (GDD) beginning 4463 GDD harvest. production per anther 82589 grains (± 14084 grains), rate 81% 12% tube germination. season started on May 20th ended June 16th duration 27 days annual integral 833 grains. low concentrations could be Northern location forest, bioclimatic transition zone between Eurosiberian areas, at limit distribution.