O objetivo deste trabalho foi desenvolver um modelo para estimar a área foliar total de bananeira, cultivar Prata-Anã, utilizando dimensões lineares da terceira folha, como o comprimento, a largura e o número total de folhas na emissão da inflorescência. As regressões lineares foram determinadas considerando-se a área foliar total de cada planta (AFT) como variável dependente e o comprimento (C) e a largura (L) da terceira folha, o produto de CxL, o número total de folhas por planta (N) e o produto de CxLxN como variáveis independentes. O modelo linear que melhor estimou a área foliar total (AFTe) da bananeira 'Prata-Anã', ao nível de 5% de significância com R² de 0,89, foi a equação AFTe = 0,5187(CxLxN) + 9603,5.

Resumo: O objetivo deste trabalho foi avaliar a distribuição do sistema radicular do cafeeiro conilon (Coffea canephora) irrigado e não irrigado. Utilizaram-se plantas de conilon da variedade clonal Emcapa 8111, genótipo 02, com cinco anos de idade. Utilizou-se o delineamento inteiramente casualizado, em parcela subsubdividida, com cinco repetições. Os tratamentos consistiram de: presença e ausência de irrigação (parcelas), 13 distâncias do tronco (dez no sentido da entrelinha e três no sentido da linha de plantio) e seis camadas de solo (0-60 cm) nas subparcelas. As raízes foram coletadas, lavadas, digitalizadas e processadas pelo programa Safira, para quantificar área superficial, comprimento, volume e diâmetro. As plantas de conilon não irrigadas apresentaram maiores área superficial, comprimento e volume de raízes por volume de solo, bem como distribuição de raízes menos discrepante na superfície do solo e em profundidade, em comparação às plantas irrigadas. O sistema de irrigação por gotejamento promove maior distribuição de raízes nas plantas irrigadas, na zona compreendida pelo bulbo úmido da irrigação.

Combining longitudinal data and statistical models from perennial crops enabled us to estimate the optimum number of measures (harvests), implying accurate discrimination of superior genotypes in those crops. Herein, the goal of this study was to determine the optimum number of harvests based on yield traits and recommend a superior graft/rootstock combination (GRC) for Citrus latifolia Tanaka. Twenty-four GRCs of 'Tahiti' acid lime were evaluated from July 2017 to August 2018 for fruit yield per plant (FYP), number of fruits per plant (NFP), and longitudinal (LFD) and transversal fruit diameter (TFD). The experimental design was a randomized complete block with 4 replications. The experimental unit consisted of three individuals, totalling 244 individuals. The GRCs were composed of (i) two hybrids that were used as rootstock, citrumelo ‘Swingle’ (Citrus paradisi x Poncirus trifoliata) and cintrandarin ‘Riverside’ (Citrus sunki x Poncirus trifoliata); and (ii) 12 different C. latifolia genotypes that were used as grafts: Bello Fruit, Eledio, Iconha, Itarana, Santa Rosa, Bearss lime, CNPMF 01, CNPMF 02, CNPMF 2001, CNPMF 5059, BRS Passos, and Persian 58. Mixed models were employed to estimate the variance components. The optimum number of harvests was determined based on selective efficiency values above 0.9. The estimated repeatability coefficients presented values of 0.14 (LFD), 0.16 (TFD), 0.36 (FYP), and 0.38 (NFD). Based on the results, four harvests were able to choose genotypes based on FYP and NFP, whereas LFD and TFD were considered inefficient traits for recommending superior GRCs.

Scab (Venturia inaequalis) is a very serious disease for apples causing up to 80% of loss in yield but there are only a few studies on postharvest quality of scab-resistant cultivars. In this study we evaluated the effect of 1-methylcyclopropene (1-MCP) on fruit quality, total phenolic content, and antioxidant capacity after storage of four scab-resistant cultivars and compared to a standard cultivar, “Golden Delicious.” In general, ethylene production and respiration rates significantly differed among cultivars, between control and 1-MCP-treated fruits, and between storage duration regimes. 1-MCP treatment retarded fruit softening and lowered juice pH but storage effect on soluble solids and acidity depended on cultivar and 1-MCP treatment. Total phenolic content was significantly affected by storage duration and 1-MCP treatment. Antioxidant capacity of the four scab-resistant cultivars was either similar to or significantly higher than that of “Golden Delicious” with the 1-MCP-treated fruits having significantly higher antioxidant capacity than the nontreated fruits after storage. Our results clearly show that the quality of four scab-resistant cultivars was comparable to that of “Golden Delicious” and 1-MCP effect differed among cultivars. These differences need to be considered in developing storage regime to minimize quality deterioration during long-term storage.

Selection of superior genotypes based on the simultaneous responses to different characteristics is a fundamental strategy in plant breeding. This study aimed to compare the efficiency of four selection index constructed using phenotypic and genotypic values in a segregating population of the cultivar Rubi Incaper 511. Eight morpho-agronomic variates and the severity of black-spot and phoma-spot were evaluated under field conditions. The classical selection index were calculated based on non-standardized phenotypic means (NSM), standardized means (SM), and genotypic values predicted by REML/BLUP (GVP), using predetermined economic weights. Additionally, the rank sum (RS) was obtained on the basis of the classification of individuals in these three selection index. For ten characteristics, the selected individuals showed a higher mean than did the original population. The best selection differential values were obtained by SM, however, the highest degree of coincidence among the selected individuals was obtained between GVP and RS (80%). The index used were efficient at selecting individuals with higher soluble solids and lower diseases severity evaluated. Therefore, for the papaya breeding programs, different selection index need to be evaluated to maximize genetic gain.

Conditioning temperature for inducing uniform ripening of ‘Abate Fetel’ pears