The aim of this study was to evaluate the effects of shoot topping and leaf removal practices on vegetative vigor, yield and physicochemical characteristics of the 'Syrah' grape in the semi-arid tropical climate conditions of the São Francisco River Valley in the northeast of Brazil. The experiment was conducted over five growing cycles from 2010 to 2012 in a 'Syrah' commercial vineyard in the municipality of Casa Nova, Bahia, Brazil. Treatments consisted of leaf removal once or twice during fruit set or at the beginning of bunch closure, and one or two shoot toppings of the berry when pea-sized or 10 days after berry growth had commenced. Leaf removal and shoot topping did not affect yield, plant vigor components nor the main attributes of fruit quality. In contrast, there was a seasonal effect with higher yield and better balance between production and vigor in grapes produced in the first half of 2012. The Syrah grape quality was favored in cycles in the first half of the year when its ripening phase coincided with the period of mild temperatures.

Abstract. The aim of this study was to characterize the yield components of the grape BRS Isis grown in tropical conditions of the São Francisco Valley. The work was carried out during five growing seasons (2013)(2014)(2015) in Petrolina, PE. The phenological cycle was 127 days between pruning to harvest. It was obtained 65.8% of sprouting on the rootstock IAC 313 and 60.4% on 'SO4'. The bud fertility rates were high, around 1.00 bunches per shoot. The average production per plant was 20.63 kg on 'SO4' and 18.34 kg on 'IAC 313', corresponding to an yield at 29.45 ton/ha/season on 'SO4' and 26.19 ton/ha/season on 'IAC 313'. The bunches are medium in size and cylindrical shaped with mass of 400 g on 'SO4' and 370 g on 'IAC 313'. The bunch length and width were also slightly higher on 'SO4' (21.32 cm × 11.89 cm) compared to 'IAC 313' (20.42 cm × 11.50 cm). The berries are large, elliptical shaped, crunchy with a neutral flavor. The grape presented SS content around 16.0• Brix and low TA (0.44 and 0.49%), giving an apropriate SS/TA ratio and pleasant taste. The results showed that 'BRS Isis' can be considered as a new option of seedless grape for the tropical viticulture in the Northeastern of Brazil.

Table grape stands out among the main fruit-bearing plants of irrigated agriculture in the São Francisco Valley region of Brazil. This study estimated repeatability and heritability coefficients and predicted genetic gains in order to select superior genotypes in grape progenies from controlled hybridizations using the Restricted Maximum Likelihood/Best Linear Unbiased Prediction (REML/BLUP) methodology. Individual plants were evaluated for the variables of production (kg per plant), number of bunches, bunch weight (g), berry diameter (mm), and soluble solids content (°Brix). We evaluated 194 hybrids from 30 crosses between Vitis vinifera and interspecific hybrids in Juazeiro, Bahia State, Brazil, over four growing seasons. Repeatability coefficients, ranging from 0.164 for soluble solids content to 0.72 for berry diameter, were estimated with accuracy values higher than 80 % for all variables, except for soluble solids content (66 %). The 30 best individuals classified for each variable exhibited genetic gains and their new estimated mean values were higher than the overall mean of the population in all variables. Regarding production and number of bunches per plant as the main variables, 15 genotypes were selected simultaneously for both variables. Among which, hybrids CPATSA 15.05, 15.06, 15.06T, and 23.103 stand out because they have trace seeds and should be selected for the following steps of genetic breeding to develop new table grape cultivars for the Brazilian semiarid region.

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