ABSTRACT
      
      The first verification that emerges from the analysis of the results is that valencian citrus surface has declined over recent years, since the 200,000 ha. SPE estimates for 2005 equivalent to 186,000 ha. physical surface, has been passed in 2009 to 190,922 ha. SPE  equivalent to 177,557 ha. physical surface.
      It’s relevant, however, that  44% of surface on that date doesn't exceed more than 10 years of age. When analyzing the structure of young plantations varietal stands in sharp contrast with 31% of total and 26,175 ha., the predominance of late oranges, replacing the Clementines of mid-season (28% of the total and 24,320 ha.) among which the variety "Clemenules" is the absolute protagonist (15,220 ha.). Also are important the digits of youth plantations of early clementines (6,825 ha.) and tangerines (4,959 ha.), the first of which can be very problematic, especially in no early surfaces where its marketing period is shorter and at the end appears the variety "Clemenules." The situation of dominance of Clementines and tangerines in young plantations is especially pronounced in Castellón province, where they represent 83% of them.
      In the provincial-level analysis highlights the marked differences between the varietal structures of the three provinces. While in Alicante highlights the relative importance of lemon and orange late, Castellón devotes 83% to clementines and tangerines. Valencia province has, in a sense, an intermediate situation, characterized by the importance of Clementines (29%) and late oranges (27%) and the important role they play in this province early oranges (22%), although expansion rate is much lower than the other two groups.
      By combining the information of the age pyramids of the plantations with data on average yields forecasts for the potential evolution of Valencian citrus production over the next decade (2009/10-2018/19) with the purpose of specify the possible temporal evolution of citrus surface, it was necessary to make certain assumptions about new plantings and tear off or abandonment of existing ones.
      It's important to reiterate that this thesis has not sought to "guess" what will be the future behavior of valencian citrus growers about it, neither build an econometric model predictive that, regardless of its possible arbitrariness, it would have been impossible to estimate from last data, because to find ourselves in front of an unprecedented crisis  that can serve as a valid reference.
      Assuming that the grubbing of plantations were limited to what could be called the death "natural" due to aging of the trees, the valencian citrus production continue to increase during the decade 2009-2019 at an average rate of 1.2% annually, reaching a volume of 3,676,979 tonnes in 2018/19 season. As expected, given the structure of the pyramids variety of ages, the increase is particularly rapid in early clementines (+4.12%) and tangerines hybrid (+3.89%), while the increase in orange production early (-1.41%) , mid-season orange (-3.16%) and late Clementina (1.09%) will be negative.
      In any case, the model developed in this work and the information contained in it, very easily allow production forecasts obtained under any other hypothesis would investigate.
      Under the assumption that the producers decide to tear off or to drop out between 2% and 3% citrus plantation area of over 10 years of age, implying an average annual decline of 1.3% of the valencian citrus surface. It is estimated that in a period of 10 years, production would fall by 5% reaching in the 2018/19 season a production of 3,139,280 t.