Sprouting, phenology, and maturation of the Italian grapevine ‘Fiano’ in Campo Largo, PR, Brazil

Despite the expansion of viticulture in Brazil, the lack of chilling hours is a factor that requires the use of growth inducers to promote sprouting. Erger™ is a product of low toxicity and efficient in the bud induction of apple. However, there is a lack of studies testing such a product on the grapevine. This research was carried out to evaluate the sprouting and phenological cycle of ‘Fiano’ grapevine after Erger™ and calcium nitrate application in comparison to hydrogen cyanamide, as well as characterizing its production in Brazil. The experiment was carried out in Campo Largo, PR, under a trellis system, with plants spaced at 1.25 × 2.7 meters. The experimental design was a randomized complete block design with four replications and three plants per plot. Different concentrations of Erger™ and calcium nitrate (3%, 5%, 7%, and control) were tested compared to the standard dose of Dormex™ (4%) to induce sprouting in ‘Fiano’ grapevine, while phenological aspects of this cultivar were evaluated following the BBCH scale. Soluble solids content, titratable acidity, and pH were evaluated weekly after the beginning of berry maturation. The main biometric and qualitative characteristics of bunches were evaluated at harvest. All treatments presented satisfactory sprouting rates in 2014, but a lower cold accumulation was observed in 2015, and Erger™ application significantly increased sprouting when compared to the control. Plants treated with Erger™ had a delay in sprouting in the two years of study, requiring more time to reach a satisfactory percentage of open buds. The anticipation of sprouting was also observed in all treatments in the second agricultural season due to higher temperatures in relation to the previous year when the occurrence of low temperatures led to a longer time to start bud opening, which was related to ecodormancy. The cultivar Fiano is productive and adapted to the conditions of Campo Largo, PR, Brazil.