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 ‘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.

Abstract The objective of this study was to evaluate the performance of hybrids and the heterosis in crosses of sweet sorghum using juicy sweet male-sterile lines and fertility-restoring lines with and without sensitivity to photoperiod. Thirty hybrids and six controls were evaluated in experiments laid out in a 6 × 6 triple lattice design. The genotypes differed for all traits. The general combining ability (GCA) of the R lines affected all traits, while the GCA of the A lines only affected juice extraction, total soluble solids, and tons of Brix per hectare (TBH). The photosensitive-restoring line CMSXS5022 had the highest positive GCA estimates for the fresh mass production and TBH traits. Heterosis was significant only for days to flowering and plant height. Overall, the photoperiod-sensitive hybrids stood out. The development of male-sterile lines requires better complementarity from restoring lines to reap the benefits of heterosis.

Abstract The objectives of this study were to estimate genetic parameters and identify traits that contribute to early yield in Manihot esculenta Crantz. Ten traits were evaluated in two experiments, one with 138 genotypes and the other with 133, using a completely randomized block design with four replications. All genotype effects were significant. The accuracy was high for the traits, except leaf retention (0.57), and reliability ranged from 0.33 to 0.75. Root weight (RW) and number of roots (NR) showed the highest selection effectiveness (CV r ), although the estimate was less than 1. Moreover, RW and NR obtained high genetic correlation (0.70). Path analysis showed that only number of roots had a significant direct effect on root weight (0.49), and no indirect effect was found. Therefore, accessions exhibited sufficient genetic variability, and indirect selection based on early evaluation of number of roots can be applied in cassava breeding for fresh root yield, increasing gain over time.