Why are so low this year fat yields in southern Spain?
Through this post, written by Rafa Navarro, you will understand what are the key factors producing low fat yields this year in the South of Spain.
Rafa Navarro is Professor at the Olive Oil School of Spain, Expert in Olive Grove Management and Teacher at the Olive Grove Management Course held in English by the Olive Oil School of Spain.
Rafa assesses a number of clients totalling around 500,000 olive trees located in different fields mainly between the South of Spain and Portugal.
The greatest dissuasive force for farmers to harvest their fruits at the beginning of the season is the fresh fat yield. This is the concept around which a large part of the profitability of their farms revolves, and it increases throughout the winter.
Most of the production of Spanish oil is currently sold in bulk, with little difference in price between qualities. This is why farmers pay more attention to harvesting costs rather tan to the quality of his harvest.
Nevertheless, early harvested EVOOs are getting more popular. Every year there are more olive oil mills that offer prices above market for those olives harvested at October/ November. The objective is to obtain the famous “green olive oils”, which are quoted better.
When harvesting the olives in late autumn, in pre-veraison and veraison, the fresh fat yield is low. Therefore, the costs of harvesting, transporting and milling have a much greater effect on the total benefits, compared with the harvesting of mature fruits in winter.
So far this year, lower fat yields are being obtained than usual, either if we talk about fresh yield or fat on dry matter.
Let’s see what are the forces that have triggered this reality:
Why are the fat yields lower than usual?
Cold and damp spring
The month of March was exceptionally rainy, with the rest of spring also being generous in rainfall and with temperatures below the average.
There was a delay in flowering, widespread for all productive areas, between 20 – 25 days compared to the usual date.
This phenological delay also occurred in the hardening of the bone, which has come to take place well in August in the coldest areas, and has been translated, already in autumn, in smaller caliber of the fruits and in a percentage of fat on dry matter , lower than other years.
Summer with softer temperatures than usual
This year, there has been hardly any water stress or fruit decay in summer, which has favored the development of the fruit and the accumulation of oil in the more torrid zones.
Rains since late summer in many productive areas.
From mid-August onwards, there have been episodes of convective rains, even with hail damage. As a result of this, the fruit has a high water content, which lowers the fat yield in fresh.
Although other years, the fact that there was rain at the end of summer, would have allowed to reduce the summer hydric stress and therefore favor the development of the fruits and the accumulation of oil, this year, by the generous spring rains and the low summer temperatures, the fruit was not depleted in almost no exploitation, so the rain has only served for the fruit to take more water.
Autumn cool, cloudy and rainy.
The maximum accumulation of oil in the fruits takes place in autumn.
Higher temperatures and higher insolation means more oil accumulated in the olivees.
With little solar radiation due to cloudiness and low temperatures, as it has been the case this year, the leaf scarcely produces photoassimilates, which are the structural pillars of olive oil.
These climatic conditions do not increase the fat on dry matter in the olive, while the fresh fat yield still does not rise, because the olive is still swollen with water.
The physiological winter of the olive tree begins at the end of the ripening. We find olives with little fat on dry matter, and little oil in fresh, due to the high water content of the fruits.
From now on, the accumulation of oil in the fruits is minimal, depending on the variety, maturity, insolation and temperatures.
Therefore, we can expect little increase of fat on dry matter in the remainder of the season. In terms of fresh yield, it would only increase slightly if rainfall episodes and high humidity are reduced, helped by temperatures below 0. This way, olives would loose water content.