Análise da evolução da canavicultura nos Tabuleiros Costeiros de Alagoas e decomposição do valor bruto da produção (VBP) nos efeitos área produtividade e preços, por meio do modelo shift-share.

The importance of sugarcane (Saccharum officinarum) for the economy of Brazil and as an energy alternative to oil derivatives is indisputable nowadays. According to IBGE, in 2013, with a production of about 28.2 million tonnes and productivity of 63.3 tons per hectare the state of Alagoas has come to occupy a prominent position in the Northeast of Brazil. In this sense the present study aims to analyze the economic importance of sugarcane in the formation of the Gross Value of Agricultural Production (GVAP) in nine municipalities in the region of the Coastal Tablelands of Alagoas State. Shift-Share Method was used for segmentation of the effects of the harvested area, the productivity and the price paid to producers in the state of Alagoas, in four periods of six years (1990 a1996, 1996-2002, 2002-2008 and 2008 to 2013) and also in the entire period (1990-2013). In the comparison between the group of municipalities in the Coastal Plains of Alagoas and the group of the largest producers in the state, the analysis of the targeted effect of the variables on the Percentage Change In (PCI) of GVAP of sugarcane indicated negative effect of the harvested area (-0.7 % and -0.6%) and positive effects of productivity (0.9% and 0.9%) and price (2.3% and 2.4%). Therefore it is concluded that the contribution of the price was decisive for increasing the PCI of sugarcane GVPA, within the two groups of municipalities studied, between 1990 and 2013.