Fenologia e produtividade de cultivares de videiras para suco em sistema agroecológico

Abstract

The Brazilian production of grapes for juice production has become an important income alternative for family farmers, motivated by the increase in the incentive of their consumption. There are several cultivars adapted to the production of juices, however, some of the cultivars recently launched in the Brazilian market have not yet been sufficiently tested in regions of subtropical climate, as in the southwestern region of Paraná, justifying this research work. In the present work, the objective of this study was to evaluate the thermal requirements, quality and productivity of the 15 grapes cultivar: Bordô, BRS Carmen, BRS Lorena, BRS Magna, BRS Rúbea, BRS Violeta, Concord, Concord Clone 30, Isabel, Isabel Precoce, Moscato Embrapa, Moscato Bailey, Niagara Branca, Niagara Rosada and Seibel 5455, produced in the agroecological system in two agricultural crops, 2015/2016 and 2016/2017, in Two Neighbors, Paraná state, Brazil. The vines were implanted in 2012, in the driving system of espaldeira. To stimulate bud buds, sulfer fertilizer solution (sulphocalcium) at 5,0% + mineral oil at 2,0% was used. The phenology of the plants was evaluated weekly using five phenological stages and the thermal requirements of the vines were obtained for different periods of the development of the plants, as well as the cycle of the same ones. The thermal requirement was defined by the calculation of day-degree accumulation (GD) since swollen buds stage to the harvest. Also evaluations of field agronomic variables were performed, such as determination of yield components, number of bunches per tree, fresh bunker biomass, yield estimate (kg.planta-1 e t.ha-1). Also, the quality of the juices (musts) obtained, such as: soluble solids (SS) in ° Brix, pH, titratable acidity (AT) in percentage and the ratio of SS/AT contents were evaluated. The cultivars BRS Violeta, Isabel Precoce and Seibel 5455 are the most productive. The cultivar Seibel 5455 has a higher end and later cycle requirement. BRS Magna and BRS Violeta have lower thermal requirements and earlier cycles. The cultivars of BRS Rúbea, BRS Violeta, Isabel, Moscato Embrapa, Moscato Bailey, Niagara Branca and Niagara Rosada grapevines have soluble solids, pH and acidity levels desirable for the production of quality whole juices. The best crop year was 2016/2017 provided the most favorable climatic conditions to overcome bud dormancy, budding, flowering and vines production.