Produtividade agrícola de cana-de-açúcar em diferentes sistemas de cultivo e idade de canavial

Abstract

Sugarcane is cultivated in more than 90 countries and stands out for adapting in diverse type of soil and climate conditions. The Brazil is the largest producer of sugarcane in the world, with 620.43 millions of tons, in an area of 8.59 millions of hectares, at the harvest 2018/2019. In the Alagoas State, sugarcane cultivation develops well, mainly between the months of April and August, when there is a greater concentration of rain, but the low rates of rain that have occurred in recent years have been reflecting negatively on the development and productivity of the cane fields in Alagoas. In addition, it is normal for sugarcane productivity to decline over the harvest cycles. There are a lot of factors that provide this reduction in crop productivity and the most important are: rainfall, the age of the plant and the cultivation system. Therefore, with this work, the objective was to study the productivity of sugarcane caused by the system of cultivation, cultivar and age of the cane field. For that, agro-industrial data of eight crop, from 2010/11 to 2017/18, of the Caeté-Matrix sugar mill, were used. The information collected was organized in Excel spreadsheets for analysis and discussion of the variables: tons of stalk per hectare (TSH) and commercially recoverable sugars (CRS). The components of the water balance (water excess and deficit) were also evaluated using the method of Thornthwaite and Mather (1955). Based on the results, was observed an average annual water deficit of 536 mm and an excess of 764 mm. Among the analyzed cultivars, the RB92579 was the one that obtained the highest average yield with 89.22 t ha -1 in the cane-plant and 79.51 t ha-1 in the first ratoon. The cultivars RB92579 and VAT90-212, independently of the cultivation system, are the most productive. And, under rainfed system and conventional sprinkling irrigation, the cultivar SP81-3250 produces more than the SP92-1631.