In the current investigation we have evaluated the yield of grapes in three EU countries – Bulgaria, Greece and Romania. These EU countries have approximately the same climatic and soil conditions for vine cultivation. The choice of these countries aims to establish the place of Bulgaria compared to Romania, which joined the EU along with Bulgaria in 2007 and Greece, an EU member since 1981. The descriptive and summary indicators, describing grapes production in Bulgaria, Greece and Romania were calculated in the first part of the investigation. The results of the statistical evaluation of average grape yields showed significant differences. The index of variance for grapes yields in Romania has the lowest values. That gave us reasons to assume that, despite the low yields, grapes production in Romania is the most stable compared with the stability in Bulgaria and Greece. The results of the second part of the investigation showed that grapes production in Bulgaria, Greece and Romania has a falling tendency. For the grapes production in the three countries, there is no clear steady trend. The investigation was made with data for grapes produced in Bulgaria, Greece and Romania extracted from the relational database Crop_ProductionBGEC, developed on the basis of the research project Structuring and Analysis of Time Series of Crop Production in Bulgaria and EU Countries of the Department of Mathematics, Informatics and Physics (09/09/2009) at the Agricultural University in Plovdiv.
Investigation of the dynamics of the average grapes yields in Bulgaria, Romania and Greece for the period 1961 - 2009