ABSTRACT The bacterial canker, caused by Xanthomonas citri pv. viticola, is the most important bacterial disease of grapevines cultivated in tropical areas. The objectives of this study were to select grape hybrids resistant to bacterial canker based on genotypic values and to evaluate the response of seedless grape hybrids to artificial infection with bacterial canker. Two experiments were conducted. The field experiment (Experiment I) was conducted with 569 hybrids, evaluated for symptoms of bacterial canker, in the absence of an experimental design, using a single individual of each genotype. Experiment II was conducted in a greenhouse, where ten seedless grape hybrids were evaluated in terms of incubation period, incidence, severity, and area under the progress curve of bacterial canker disease incidence, in a completely randomized design. The use of the residual maximum likelihood/best unbiased linear prediction methodology allowed the selection of 40 grape hybrids with lower genotypic values for resistance to bacterial canker. The CPATSA 49.25 and CPATSA 49.86 hybrids showed greater resistance to bacterial canker in all epidemiological parameters evaluated under greenhouse conditions.

ABSTRACT Over the past decade, the business of producing juice from grapes (Vitis labrusca L. and hybrids) has been expanding in response to increasing consumption encouraged by campaigns promoting the benefits grape juice can have on health. This study aimed to determine the effect of the production cycle, vine training system, and rootstock on the yield and physical and physical-chemical characteristics of ‘BRS Magna’ grapes grown in the Vale do Submédio São Francisco in the northeastern region of Brazil. The study was conducted in Petrolina, Pernambuco, over eight production cycles (2017 to 2020). The grapevines were trained in three vine training trellis systems: espalier, lyre, and pergola; and grafted onto two rootstocks: IAC 572 and IAC 766. The production cycle, training system, and rootstocks affected the yield components, vigor, and physical characteristics of the BRS Magna grapes. The combination of the pergola training system and rootstock IAC 766 stood out from the others, providing mean yields estimated at 26 t ha –1 per production cycle. The soluble solids content (SS), titratable acidity (TA), and SS TA –1 ratio were affected neither by the training system nor the rootstock, and higher values for SS and lower values for TA were obtained in the first, second, fourth and eighth production cycles. Thus, the pergola training system and rootstock IAC 766 are recommended for promoting yield gains in the ‘BRS Magna’ grape in the Vale do Submédio São Francisco.

ABSTRACT The aim of the present study was to investigate the effect of the grape cultivar combined with rootstocks on yield and fruit traits of grapevine in the São Francisco Valley, in the Northeast of Brazil. The experiment was carried out over eight growing seasons (2014 to 2018) in Petrolina, Pernambuco, Brazil. The treatments were represented by five seedless table grape cultivars (A Dona, Arizul, Marroo Seedless, BRS Clara, and BRS Maria Bonita) and six rootstocks (IAC 313, IAC 766, IAC 572, SO4, Harmony, and Paulsen 1103) in a randomized block experimental design with three replicates. Principal component analysis showed that 59.2% of the variation found in the data was related to principal component (PC) 1 (42.76%) associated with the number of bunches and berry weight, length, and diameter variables; and PC 2 (16.4%) correlated with yield per vine. The yield per vine showed a significant positive correlation with number of bunches, bunch length, soluble solids content, and titratable acidity, and showed a negative correlation with berry length. A Dona and Marroo Seedless grapes had the highest yield, regardless of the rootstocks they were grafted onto, whereas BRS Clara had high values for soluble solids content and titratable acidity and a balanced SS/TA ratio. In contrast, BRS Maria Bonita had the lowest yielding grape cultivar, although it had the greatest bunch weight and berry length. The rootstocks affected the agronomic performance of the table grape cultivars in most variables, depending on the effect of different grape cultivars × rootstock combinations.

Abstract The aim of the present study was to identify grape parent varieties that lead to greater frequency of seedless genotypes in the progenies and to understand the relationships between the seedless trait and other fruit traits. A group of 200 hybrids (F1) originating from 38 crosses among cultivars of Vitis vinifera L. and interspecific hybrids were evaluated in Juazeiro, Bahia, Brazil, over six consecutive crop seasons (2018 to 2021). The progenies were placed in three classes based on seedlessness: completely seedless (class 1), seed traces or soft seeds (class 2), and with seeds (class 3). The mean dry matter of the seeds in each class was 0 mg, 2.3 mg, and 25.7 mg respectively, which corresponded to 40 genotypes (20%) in class 1, 52 genotypes (26%) in class 2, and 108 (54%) in class 3. The interspecific cross ‘BRS Isis’ and ‘Marroo Seedless’ stood out through favoring high frequency of seedless individuals in the progeny (47.5%). The traits associated with berry size (length, diameter, and weight) had high positive correlations with each other. The results obtained make an important contribution for table grape breeding aiming at the development of new table grape cultivars.

Resumo O objetivo do presente trabalho foi identificar genitores que proporcionem maior frequência de genótipos apirenos nas progênies, bem como compreender as relações entre a característica apirenia e outras características do fruto. Foram avaliados 200 híbridos (F1) originados de 38 cruzamentos entre cultivares de Vitis vinífera L., e híbridos interespecíficos, em Juazeiro, Bahia, durante seis safras consecutivas (2018 a 2021). As progênies foram classificadas em três classes quanto à apirenia: completamente sem sementes (classe 1), presença de traço ou semenseparates macias (classe 2) e com sementes (classe 3). A massa fresca média das sementes, em cada classe, foi de 0mg, 2,3mg e 25,7mg, respectivamente, o que correspondeu a 40 genótipos (20%) na classe 1, 52 genótipos (26%) na classe 2 e 108 (54%) na classe 3. O cruzamento interespecífico ‘BRS Isis’ e ‘Marroo Seedless’ destacou-se por favorecer elevada frequência de indivíduos sem sementes na progênie (47,5%). As características associadas ao tamanho de baga (comprimento, diâmetro e massa) apresentaram correlações positivas e elevadas entre si. Os resultados obtidos fornecem subsídios importantes para o planejamento de cruzamentos, avaliação das progênies e seleção de híbridos visando ao desenvolvimento de novas cultivares de uvas de mesa.

Abstract ‘BRS Tainá’ is a new seedless table grape cultivar developed and recommended for the Submedium of São Francisco Valley, the main producing and exporting region of table grapes in Brazil. The objective of this study was to evaluate the influence of rootstock on vigor, bud fertility, sucrose and total soluble carbohydrates content in leaves of ‘BRS Tainá’ vine cultivated in semi-arid environmental conditions in the Brazilian Northeast. The treatments were represented by eight rootstocks: ‘101-14 MgT’, ‘IAC 313’, ‘IAC 572’, ‘IAC 766’, ‘Paulsen 1103’, ‘Ramsey’, ‘SO4’ and ‘Teleki 5C’. The experimental design was in randomized blocks with four replications, in split plots, the production cycles were considered as plots, and eight rootstocks as subplots. The following variables were evaluated: pruning weight, stem diameter, number of lateral bunches, bud fertility, sucrose and total soluble carbohydrates content in leaves. The ‘BRS Tainá’ vine had moderate canopy vigor and 54% of bud fertility. The carbohydrate content and sucrose in the leaves did not differ among treatments during pruning. Therefore, it is possible that there is no effect of the rootstock on the initial vegetative growth of ‘BRS Tainá’ vines, which vigor and bud fertility remained stable in the initial production cycles.

Resumo ‘BRS Tainá’ é uma nova cultivar de uvas de mesa sem sementes desenvolvida e recomendada para o Vale do Submédio São Francisco, principal região produtora e exportadora de uvas finas no Brasil. O objetivo deste trabalho foi avaliar a influência do porta-enxerto sobre o vigor, a fertilidade de gemas e o conteúdo de sacarose e carboidratos solúveis totais nas folhas de videiras ‘BRS Tainá’, cultivadas em condições semiáridas do Nordeste brasileiro. Os tratamentos foram constituídos por oito porta-enxertos: ‘101-14 MgT’, ‘IAC 313’, ‘IAC 572’, ‘IAC 766’, ‘Paulsen 1103’, ‘Ramsey’, ‘SO4’ e ‘Teleki 5C’. O delineamento experimental foi em blocos casualizados, em parcelas subdivididas, com quatro repetições, sendo os ciclos de produção considerados como parcelas, e os oito porta-enxertos, como subparcelas. As seguintes variáveis foram avaliadas: massa fresca de ramos e folhas, diâmetro de caule, número de saídas laterais, índice de fertilidade de gemas, conteúdo de sacarose e carboidrato nas folhas. A videira ‘BRS Tainá’ apresentou vigor da copa moderado e fertilidade de gemas em 54%. O conteúdo de carboidratos solúveis totais e de sacarose nas folhas não diferiu entre os porta-enxertos durante a poda de produção. Logo, é possível inferir que não houve influência do porta-enxerto no desenvolvimento vegetativo inicial de videiras ‘BRS Tainá’, visto que apresentam estabilidade no vigor e fertilidade de gemas nos primeiros ciclos de produção.

Resumo Porta enxertos são amplamente utilizados na viticucultura mundial e podem influenciar os componentes de produção e a qualidade das uvas, sucos e vinhos. O objetivo do presente trabalho foi determinar a influência do porta enxerto no desempenho produtivo, características físicas e físico químicas de uvas para suco ‘BRS Magna’ cultivada no Vale do Submédio São Francisco. O estudo foi realizado durante seis ciclos de produção no período de 2015 à 2019, no Campo Experimental de Bebedouro da Embrapa Semiárido em Petrolina, PE. As seguintes variáveis foram avaliadas: produtividade estimada; número de cachos por planta; massa fresca de ramos e folhas; massa do cacho; comprimento e largura do cacho; massa da baga; teor de sólidos solúveis totais (SS), acidez titulável (AT) e relação SS/AT. Efeitos significativos do porta enxerto foram observados em todas as variáveis com exceção do teor de SS. O porta enxerto IAC 572 promoveu aumentos de até 61% na produtividade de videiras ‘BRS Magna’, com respostas significativas nos demais componentes de produção. A dispersão gráfica em relação aos três primeiros componentes principais permitiu a separação dos porta enxertos em função dos ciclos de produção. Os valores médios para teor de SS e AT caracterizam esta cultivar no Vale do Submédio São Francisco, com alto conteúdo de sólidos solúveis e baixa acidez resultado em elevada relação SS/AT, com potencial para elaboração de sucos de elevada qualidade independente do porta enxerto utilizado.

Abstract Rootstocks are widely used in viticulture worldwide and can affect the yield components and quality of grapes and their juices and wines. The aim of the present study was to determine the effect of the rootstock on the yield performance and physical and physical-chemical traits of ‘BRS Magna’ juice grapes grown in the Submédio do Vale do São Francisco. The study was performed over six production cycles in the period from 2015 to 2019 in the Bebedouro experimental field of Embrapa Semiárido in Petrolina, PE, Brazil. The treatments consisted of seven grapevine rootstocks: IAC 572, IAC 766, IAC 313, Paulsen 1103, SO4, Harmony, and Freedom. The following variables were evaluated: estimated yield, number of grape bunches per plant, branch and leaf fresh matter, bunch weight, bunch length and width, berry weight, total soluble solids content (SS), titratable acidity (TA), and SS to TA ratio (SS:TA). Significant effects of the rootstock were observed in all the variables except for SS. The rootstock ‘IAC 572’ led to increases of up to 61% in the yield of ‘BRS Magna’ grapevines, or 32.78 ton.ha-1, with significant responses in the other yield components. Results of the scatterplot in relation to the first three principal components allowed separation of the rootstocks in accordance with production cycles. The mean values for SS and TA characterize this cultivar in the Vale do Submédio São Francisco, with high soluble solids content and low acidity resulting in high SS:TA, as having potential for preparation of high quality juices, regardless of the rootstock used.

ABSTRACT The aim of this research was to study the influence of training system and rootstock on the yield, vigor and physiology of the ‘Chenin Blanc’ grapevine at São Francisco Valley, northeastern Brazil. An experiment was carried out on eight harvests, from 2013 to 2017, in Petrolina, in the state of Pernambuco. Grapevines were grown under two training systems, lyre and espalier, and five rootstocks: ‘IAC 572’, ‘IAC 313’, ‘IAC 766’, ‘Paulsen 1103’ and ‘SO4’, using a split-plot randomized block design, with training systems assigned to the main plot and the rootstock assigned to the subplot. Lyre favored an increase in the number of bunches, branches and leaf mass in the harvest of the first semester of the year, while in the second semester there were increases of 40 % in the number of bunches and 10 % in leaf mass. Lyre promoted more balanced vines, showing a better ratio between production and pruning weight (Ravaz index). The rootstocks ‘IAC 766’, ‘IAC 313’ and ‘IAC 572’ increased yield and bunch mass under both training systems, while ‘SO4’ reduced yield and vigor. The stomatal conductance and instantaneous efficiency of water use were not influenced by either the training system or the rootstock. Under tropical conditions in the São Francisco Valley, ‘Chenin Blanc’ grapevine may be grown under the lyre training system, preferably on the ‘IAC 766’ rootstock, to obtain high yields and balanced grapevines.

Abstract The new table grape cultivar BRS Tainá produces white firm seedless grapes, agreeable flavor, balanced sugar-acid ratio, good berry adherence to the pedicel and yield of 50 ton ha-1 year-1. It is recommended for the tropical conditions of the Submédio do Vale do São Francisco. Propagative material is acquired from nurseries licensed by Embrapa.

ABSTRACT The São Francisco Valley is the main producing region of table grape in Brazil. The objective of this work was to evaluate the agronomic performance and physicochemical characteristics of 14 seedless table grape genotypes to select those with potential to be used in commercial crops in the São Francisco Valley, Brazil, or as parents in breeding programs. The experiment was carried out over five crop seasons (2014 to 2018), in Petrolina, PE, Brazil. The treatments consisted of 14 seedless table grape genotypes. The results showed significant effects for all variables evaluated. The highest estimated yield per production cycle were found for ‘Marroo Seedless’ (26.5 t·ha-1), ‘BRS Linda’ (26.4 t·ha-1), ‘CNPUV 23’ (24.9 t·ha-1), ‘A1105’ (24.3 t·ha-1),and ‘A Dona’ (20.2 t·ha-1). Soluble solid (SS) content varied from 13.35 ºBrix (‘CNPUV 23’) to 21.63 ºBrix (‘A Dona’). The titratable acidity (TA) of the genotypes varied from 0.27 g·100 mL-1 (‘CNPUV 23’) to 0.72 g·100 mL-1 (‘Crimson Seedless’). Principal component analysis showed that the first three principal components explained 81.9% of the data variance, and grouped the best genotypes for production components and fruit chemical composition on different sides of the X-axis. These results allowed the identification of a group of seedless grape cultivars that can be used for commercial crops or as parents for controlled crossings in a local table grape breeding program.

RESUMO ‘BRS Vitória’ é a mais importante cultivar brasileira de uvas de mesa, destacando-se pela ausência de sementes, sabor agradável, elevada produtividade e resisência ao míldio. O objetivo do presente estudo foi determinar o efeito do porta-enxerto no rendimento, componentes de produção, vigor, características físicas e físico químicas da uva ‘BRS Vitória’ sob irrigação no semi-árido brasileiro. O experimento foi realizado em oito ciclos consecutivos de produção, no período de 2015 a 2018, em uma área comercial no projeto Senador Nilo Coelho, Petrolina, PE. Os tratamentos foram representados por sete porta-enxertos: ‘IAC 572’, ‘IAC 766’, ‘IAC 313’, ‘Harmony’, ‘SO4’, ‘Paulsen 1103’ e ‘Freedom’, em delineamento experimental de blocos ao acaso, com quatro repetições. Os resultados foram variáveis entre os ciclos de produção, com efeitos significativos do porta-enxerto em alguns ciclos, como também na média geral dos ciclos. As variáveis massa dos ramos após a poda, porcentagem de brotação, índice de fertilidade de gemas e acidez titulável não foram afetadas pelo porta-enxerto em nenhum dos ciclos de produção avaliados neste estudo. O porta-enxerto ‘Harmony’ promoveu maior massa e diâmetro da baga mas reduziu o teor de sólidos solúveis das uvas. A cultivar BRS Vitória apresentou vigor moderado, elevada fertilidade de gemas e produtividade, características de cachos e bagas e teor de acúcares e ácidos que atendem as exigências dos mercados mais exigentes em todos os porta enxertos avaliados neste estudo.

ABSTRACT ‘BRS Vitoria’ is the most important Brazilian table grape cultivar in the domestic and foreign markets, standing out for the seedleness, pleasant flavor, high yield and mildew resistance. The aim of the present study was to determine the effect of the rootstock on the yield, production components, vigor, and physical and chemical characteristics of the ‘BRS Vitória’ grape under irrigation in the Brazilian semi-arid region. The experiment was conducted over eight consecutive production cycles in the period from 2015 to 2018 in a commercial area in the Senador Nilo Coelho project, Petrolina, PE. The treatments were represented by seven rootstocks: ‘IAC 572’, ‘IAC 766’, ‘IAC 313’, ‘Harmony’, ‘SO4’, ‘Paulsen 1103’, and ‘Freedom’, using a randomized block experimental design with four replications. The results were variable among production cycles, with significant effects of the rootstock in some cycles and/or in the overall mean of the cycles. The variables of pruning weight, sprouting, bud fertility, and titratable acidity were not affected by the rootstock in any of the production cycles evaluated in this study. ‘Harmony’ rootstock promoted greater berry mass and diameter but reduced the soluble solids content. Vines of ‘BRS Vitória’ showed moderate vigor, high bud fertility and yield, satisfactory characteristics of bunch and berry, sugars and acids content that meet the requirements of the most demanding markets in all the rootstocks evaluated in this study.

RESUMO O Vale do São Francisco destaca-se entre as principais regiões vitivinícolas brasileiras, sendo o cultivar ‘Syrah’ muito importante na elaboração de vinhos tintos. O objetivo deste trabalho foi avaliar a influência do sistema de condução e porta-enxerto sobre o rendimento e outras variáveis agronômicas do cultivar ‘Syrah’ durante oito safras consecutivas em ambiente tropical semi árido no Vale do São Francisco. Um experimento foi realizado em Petrolina, PE, avaliando-se videiras ‘Syrah’, conduzidas nos sistemas de lira e espaldeira e enxertadas sobre os porta-enxertos IAC 572, IAC 766, IAC 313, SO4, 1103 Paulsen e Harmony. Utilizou-se delineamento experimental em blocos ao acaso com quatro repetições e parcelas subdivididas. Observou-se interação significativa entre sistema de condução e porta-enxerto para produção, número de cachos e massa foliar. O sistema de condução em lira aumentou a produção, número de cachos e índice de Ravaz, favorecendo o desenvolvimento de videiras mais equilibradas. O porta enxerto IAC 572 promoveu maior vigor reduzindo significativamente a produção, número de cachos, fertilidade de gemas e índice de Ravaz. Os demais porta enxertos foram similares entre si na maioria das variáveis. Fotossíntese líquida, condutância estomática e eficiência instantânea do uso da água não foram influenciadas pelo sistema de condução e porta enxerto. Os resultados obtidos evidenciam a influência do sistema de condução associado ao porta-enxerto sobre variáveis agronômicas da videira ‘Syrah’, recomendando-se o seu cultivo em lira enxertada sobre 1103 Paulsen ou IAC 313 nas condições tropicais semiáridas do Vale do São Francisco.

ABSTRACT The Vale do São Francisco stands out among the main Brazilian wine regions, and ‘Syrah’ is a grape cultivar very important to produce red wines. The objective of this study was to evaluate the influence of training systems and rootstocks on the yield and other agronomic variables of ‘Syrah’ grapevines during eight consecutive harvests in the tropical semiarid environment in the Vale do São Francisco. An experiment was carried out in Petrolina, state of Pernambuco, with ‘Syrah’ trained to lyre and espalier systems and grafted on IAC 572, IAC 766, IAC 313, SO4, 1103 Paulsen and Harmony rootstocks. A randomized block design with four replicates and split plots was used. There was a significant interaction between the training system and rootstock for yield, number of clusters and foliar mass. The lyre system increased yield, cluster number and Ravaz index, favoring the development of more balanced grapevines. The IAC 572 rootstock promoted greater vigor by reducing yield, cluster number, bud fertility and Ravaz index. The other rootstocks were similar to each other in most variables. Net photosynthesis, stomatal conductance and instantaneous efficiency of water use were not influenced by the training system and the rootstock. The results obtained evidenced the influence of the training system associated to the rootstock on agronomic variable and yield of ‘Syrah’, recommending lyre training and grafting on 1103 Paulsen or IAC 313 in the semi-arid tropical conditions of the Vale do São Francisco.

ABSTRACT: 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.

RESUMO: O presente trabalho teve como objetivo estudar o desempenho produtivo e características físico-químicas das uvas ‘BRS Magna’ e ‘Isabel Precoce’ submetidas a dois tipos de poda. Um experimento foi realizado durante dois ciclos de produção, nos anos de 2013 e 2014, em um vinhedo comercial em Petrolina, PE. Os tratamentos foram representados por duas cultivares copa, ‘Isabel Precoce’ e ‘BRS Magna’, e dois tipos de poda, com seleção de ramos laterais na formação da planta (P1) e sem seleção de ramos laterais (P2), utilizando delineamento experimental em blocos ao acaso em parcelas subdivididas e quatro repetições. A quantidade de gemas mantidas na videira após a poda é mais elevada na poda P2, favorecendo o aumento da produtividade, mas o tamanho dos cachos e das bagas e o teor de sólidos solúveis e acidez titulável não foram influenciados pelo tipo de poda. O tamanho dos cachos e das bagas da cultivar ‘BRS Magna’ é, de modo geral, maior que os de ‘Isabel Precoce’. Por outro lado, o teor de sólidos solúveis e acidez titulável variaram entre as cultivares em função do ciclo de produção e do tipo de poda, estando dentro dos padrões descritos para ambas cultivares e aceitos pela legislação brasileira.

ABSTRACT: The objective of this study was to evaluate the productive performance and physicochemical characteristics of ‘BRS Magna’ and ‘Isabel Precoce’ grapes influenced by two types of pruning. The experiment was carried out during two growing seasons in a commercial vineyard of Petrolina, PE, in the period 2013-2014. Treatments were represented by two cultivars, ‘Isabel Precoce’ and ‘BRS Magna’, and two types of pruning, with selection during plant formation (P1) and without selection (P2) of lateral branches, using a randomized experimental block design, in subdivided plots and four replicates. After pruning P2, the amount of buds kept on vines was greater than after pruning P1, favoring an increase in yield. However, the sizes of bunches and berries, content of soluble solids, and titratable acidity were not influenced by the pruning type. In general, the sizes of bunches and berries in ‘BRS Magna’ were larger than in the ‘Isabel Precoce’ cultivar. Conversely, content of soluble solids and titratable acidity varied among cultivars as a function of production cycle and type of pruning; however, within the standards described for both cultivars and accepted by the Brazilian legislation.

RESUMO O conhecimento da fertilidade de gemas é um importante subsídio para a seleção de novas cultivares de uvas de mesa com alto potencial produtivo. O objetivo deste trabalho foi determinar a porcentagem de brotação e índice de fertilidade de gemas de 14 cultivares e seleções de melhoramento de uvas de mesa durante cinco ciclos de produção. O trabalho foi realizado no Campo Experimental de Bebedouro da Embrapa Semiárido, em Petrolina-PE, no período 2013-2015, considerando-se como fontes de variação 14 genótipos de uvas de mesa e 5 ciclos de produção. O delineamento experimental foi em blocos ao acaso, avaliando-se a porcentagem de brotação e o índice médio de fertilidade de gemas. Efeito significativo do genótipo sobre a brotação foi observada apenas no 1º e 2º ciclos de produção, entretanto a fertilidade de gemas apresentou interação significativa entre genótipo e ciclo de produção, sendo os maiores valores médios de fertilidade de gemas obtido no 5º ciclo, no 2º semestre de 2015. As cultivares ‘A Dona’, ‘A1105’, ‘BRS Clara’ e Marroo Seedless’ destacaram-se pela alta fertilidade de gemas (médias de 0,78 a 0,95 cachos.broto-1) em todos os ciclos avaliados, com valores mais elevados nas gemas apicais da vara (8ª e 9ª gemas). Estes resultados evidenciam o potencial produtivo dessas novas cultivares no Vale do São Francisco.

ABSTRACT Knowledge of bud fertility is an important aid in selection of new cultivars of table grapes with high yield potential. The aim of this study was to determine the sprouting percentage and fertility index of buds of 11 cultivars and table grape breeding selections over five production cycles. The study was carried out at the Bebedouro Experimental Field of Embrapa Semiárido in Petrolina-PE, Brazil, in the period 2013-2015 considering 14 table grape genotypes and 5 production cycles as sources of variation. A randomized block experimental design was used, evaluating sprouting percentage and the mean bud fertility index. A significant effect of the genotype on sprouting was observed only in the first and second production cycles; however, bud fertility exhibited significant interaction between the genotype and the production cycle, and the highest mean values of bud fertility were obtained in the fifth cycle in the 2nd semester of 2015. The cultivars ‘A Dona’, ‘A1105’, ‘BRS Clara’, and Marroo Seedless’ stood out through high bud fertility (mean values from 0.78 to 0.95 bunches/shoot) in all the cycles evaluated, with higher values in the terminal buds of the cane (8th and 9th buds). These results show the yield potential of these new cultivars in the São Francisco Valley region.

RESUMO Este trabalho teve como objetivo avaliar a influência de diferentes densidades de brotos e de cachos, por meio das práticas de desbrota e desbaste, sobre os componentes de produção e qualidade dos cachos de uvas ‘Sugraone’ e ‘Thompson Seedless’ no Vale do São Francisco. Os experimentos foram realizados durante dois ciclos de produção (2010 e 2012), em vinhedos comerciais no município de Lagoa Grande, PE. Os tratamentos estavam distribuídos em parcelas subdivididas, representadas por três densidades de brotos e três densidades de cachos, em delineamento experimental em blocos ao acaso. A produção em ‘Thompson Seedless’ foi 25,9% maior em plantas mantidas com 6 cachos.m-2, alcançando 20,7 e 27,0 Kg.planta-1, nas colheitas de 2010 e 2012, respectivamente. Na cultivar Sugraone, não houve efeitos sobre a produção por planta, embora a massa do cacho e da baga tenham sido maiores, em, pelo menos, um ciclo de produção, respectivamente, nos tratamentos com densidade de 5 cachos.m-2 e 7 brotos.m-2. Em ‘Thompson Seedless’, uvas mais firmes foram colhidas em 2012, de plantas com 7 ou 8 ramos.m-2, enquanto os teores de sólidos solúveis e de açúcares solúveis totais foram maiores nas uvas colhidas de plantas com menores densidades de brotos e cachos. Entretanto, na ‘Sugraone’ não se observou efeito dos tratamentos sobre o teor de sólidos solúveis totais. Recomenda-se, para a cultivar Thompson Seedless, densidade de 7 brotos.m-2 associado a 6 cachos.m-2 por favorecer a produtividade sem prejuízo da qualidade dos frutos, enquanto para a cv. Sugraone, densidades de 7 brotos.m-2 e 5 cachos.m-2 podem ser utilizadas para incrementar a massa de cachos e bagas.

ABSTRACT This study aimed to evaluate the effect of shoot and bunch density through thinning practices on yield components and quality of ‘Thompson Seedless’ and ‘Sugraone’ grapevines in the São Francisco River valley. The experiments were carried out during two growing seasons (2010 and 2012) in commercial vineyards of Lagoa Grande, state of Pernambuco, Brazil. Treatments were a split plot represented by three shoot densities and three bunch densities in a random block design. The yield of ‘Thompson Seedless’ grapevine was up to 25.9% higher in plants kept with 6 bunches.m-2, reaching 20.7 and 27.0 kg.plant-1, in the 2010 and 2012 crop years, respectively. Although effects on yield were not observed in ‘Sugraone’ cultivar, bunch and berry mass was higher in treatments with 5 bunches.m-2 and 7 shoots.m-2, respectively, in the last production cycles. ‘Thompson Seedless’ grapes with greater berry firmness were harvested in 2012 in plants submitted to densities of 7 or 8 shoots.m-2, while the contents of soluble solids and total soluble sugars were higher in grapes harvested from plants with lower shoot and bunch densities. However no effects of treatments on the contents of soluble solids were observed in ‘Sugraoen’ grapes. The use of 7 shoots.m-2 associated to 6 bunches.m-2 is recommended for ‘Thompson Seedless’ grapevines because it increased yield with no harm to fruit quality, while for ‘Sugraone’, densities of 7 shoots.m-2 and 5 bunches.m-2 can be used to increase the mass of bunches and berries.