Impacts of seasonality on the phenology of three grapevine cultivars in the semi-arid climate

Abstract

Abstract This study aimed to investigate the impacts of the growing season on the physiological performance, phenological cycle, and yield of grapevines grown in a semiarid climate. Thus, we established a field experiment in two growing seasons using cultivars with intermediate cycles (BRS Magna and BRS Núbia), and early cycles (BRS Violeta) in Bom Jesus, Piauí, Brazil. Our results suggest that vines cultivated during the second season (September-December) anticipated the phenology from sprouting to berry maturation (BBCH01-BBCH89) of all studied cultivars. The vines cultivated in the 2nd season had an average duration of 109 days after pruning. The growing season within each cultivar level showed that the 2nd season was the best for all studied cultivars. In all cases, plants from the second growing season showed higher rates of CO2 assimilation, transpiration, stomatal conductance, leaf temperature, and the relationship between internal, and external CO2 concentrations (Ci/Ca ratio). BRS Magna had the highest production (3563.5 kg/plant), the highest number of berries per bunch (34.5), longitudinal diameter (35.1 mm), and transverse diameter, universal of the berry (15.3 mm), fruit mass (61.83 g), berries (2.4 g), and total soluble solids (14.9 °Brix). Principal component analysis (PCA) showed that the studied cultivars differed from each other, highlighting alterations in the analyzed variables as affected by growing season. Our findings provide relevant information for the growing season, and behavior of vine cultivars to be used as a basis for viticulture cultivation in semiarid environments.