As pereiras européias e asiáticas, cultivadas sob condições de inverno ameno, como na região Sul do Brasil, apresentam problemas de adaptação. Durante o inverno, as oscilações térmicas e o baixo ...acúmulo de frio têm sido referidos por alguns autores como causas do abortamento de gemas florais. O objetivo deste trabalho foi determinar o balanço de carboidratos em tecidos de gemas florais de duas cultivares de pereiras: Kieffer (P. communis x P. pyrifolia) e Housui (P. pyrifolia). Os tecidos de gemas florais e da base de gemas foram coletados mensalmente, de fevereiro a setembro de 2002, de plantas de pomar da Embrapa Clima Temperado, Pelotas-RS, coordenadas 32°51' S e 52°21'O, localizado a 230 metros de altitude. O material vegetal foi analisado separadamente quanto às concentrações de açúcares solúveis (por cromatografia gasosa) e porcentagens de amido (por espectrofotometria). Em ambas as cultivares, observou-se que a base da gema é um importante local de reserva. Ocorreram significativos aumentos de açúcares solúveis nas gemas das duas cultivares na fase que antecede a brotação. Em setembro, os açúcares solúveis totais na matéria seca (MS), nas gemas florais da cv. Housui (38,33 mg g-1), foram menores do que os observados nos tecidos da cv. Kieffer (50,39 mg g-1), cultivar melhor adaptada às condições climáticas. O açúcar-álcool sorbitol, seguido da sacarose, foi o açúcar solúvel mais abundante nos tecidos das duas cultivares.
Most of the European and Asian pear cultivars, when cultivated under mild winter such as in Southern of Brazil, have adaptation problems. The temperature oscillations during the winter and the little chilling hours accumulation have been considered by some researchers as causes of flower bud abortion. The purpose of this study was to determine the levels of carbohydrates in tissues of flower buds of the two pear cultivars: Kieffer (P. communis x P. pyrifolia) and Housui (P. pyrifolia). Flower bud and its surrounding base tissues (bud cushion) were monthly collected since February until September 2002, from pear trees in a orchard of Embrapa Temperate Climate Research Center (32°51' S and 52°21'W), located at 230 m of altitude. The tissues of the flower buds and bud cushion were separately analysed for soluble sugars concentration (by GLC) and starch percentage (by spectrophotometry), in the Laboratory of Plant Physiology of Embrapa. It was observed that the bud cushion tissue is an important site of starch accumulation on both cultivars. There were marked increases in soluble sugars in the flower bud tissues of both cultivars, previously to budbreak. However the total soluble sugars accumulation in the buds of cv. Housui, in September (38,33 mg g-1 DW dry weight), were lower than those of cv. Kieffer (50,39 mg g-1 DW), which has better adaptation. Sorbitol followed by sucrose was the more abundant water soluble sugar in both tissues of the two cultivars.
As pereiras européias e asiáticas, cultivadas sob condições de inverno ameno, como na região Sul do Brasil, apresentam problemas de adaptação. Durante o inverno, as oscilações térmicas e o baixo ...acúmulo de frio têm sido referidos por alguns autores como causas do abortamento de gemas florais. O objetivo deste trabalho foi determinar o balanço de carboidratos em tecidos de gemas florais de duas cultivares de pereiras: Kieffer (P. communis x P. pyrifolia) e Housui (P. pyrifolia). Os tecidos de gemas florais e da base de gemas foram coletados mensalmente, de fevereiro a setembro de 2002, de plantas de pomar da Embrapa Clima Temperado, Pelotas-RS, coordenadas 32°51' S e 52°21'O, localizado a 230 metros de altitude. O material vegetal foi analisado separadamente quanto às concentrações de açúcares solúveis (por cromatografia gasosa) e porcentagens de amido (por espectrofotometria). Em ambas as cultivares, observou-se que a base da gema é um importante local de reserva. Ocorreram significativos aumentos de açúcares solúveis nas gemas das duas cultivares na fase que antecede a brotação. Em setembro, os açúcares solúveis totais na matéria seca (MS), nas gemas florais da cv. Housui (38,33 mg g-1), foram menores do que os observados nos tecidos da cv. Kieffer (50,39 mg g-1), cultivar melhor adaptada às condições climáticas. O açúcar-álcool sorbitol, seguido da sacarose, foi o açúcar solúvel mais abundante nos tecidos das duas cultivares.Most of the European and Asian pear cultivars, when cultivated under mild winter such as in Southern of Brazil, have adaptation problems. The temperature oscillations during the winter and the little chilling hours accumulation have been considered by some researchers as causes of flower bud abortion. The purpose of this study was to determine the levels of carbohydrates in tissues of flower buds of the two pear cultivars: Kieffer (P. communis x P. pyrifolia) and Housui (P. pyrifolia). Flower bud and its surrounding base tissues (bud cushion) were monthly collected since February until September 2002, from pear trees in a orchard of Embrapa Temperate Climate Research Center (32°51' S and 52°21'W), located at 230 m of altitude. The tissues of the flower buds and bud cushion were separately analysed for soluble sugars concentration (by GLC) and starch percentage (by spectrophotometry), in the Laboratory of Plant Physiology of Embrapa. It was observed that the bud cushion tissue is an important site of starch accumulation on both cultivars. There were marked increases in soluble sugars in the flower bud tissues of both cultivars, previously to budbreak. However the total soluble sugars accumulation in the buds of cv. Housui, in September (38,33 mg g-1 DW dry weight), were lower than those of cv. Kieffer (50,39 mg g-1 DW), which has better adaptation. Sorbitol followed by sucrose was the more abundant water soluble sugar in both tissues of the two cultivars.
Abstract – The performance of ‘Carrick’ pear grafted on different quince rootstocks was evaluated at the experimental field of the Federal University of Pelotas. Plant material consisted of ...6-year-old ‘Carrick’ pear in spacing 1 x 5m (2000 trees ha-1), trained as central leader and grafted on quinces ‘Portugal’, ‘MC’, ‘BA29’, ‘D’vranja’ and ‘Inta 267’. Assessed parameters were: yield, yield efficiency and trunk cross sectional area (TCSA). Yield efficiency was higher with ‘Portugal’ and ‘MC’ in all growing seasons. Rootstock ‘Portugal’ induced the greatest yield in all growing seasons but 2011/2012, when no differences were found among the rootstocks. The greatest cumulative yield was found with ‘Portugal’. By TCSA, rootstocks ‘Inta 267’, ‘D’Vranja’ and ‘BA29’ are more vigorous than ‘MC’ and ‘Portugal’. ‘Portugal’ was the most productive rootstock for ‘Carrick’ and also one of the most dwarfing.Resumo – O desempenho da pereira ‘Carrick’ enxertada em diferentes porta-enxertos de marmeleiro foi avaliado durante quatro safras no campo experimental da Universidade Federal de Pelotas. O material vegetal consistiu de plantas de pereira ‘Carrick’ com seis anos de idade (1x5m; 2.000 plantas ha-1; conduzidas no sistema de líder central), enxertadas nos portaenxertos Portugal, MC, BA29, D’vranja e Inta 267. Os parâmetros avaliados foram: produtividade, eficiência produtiva e área da seção transversal do tronco (ASTT). A eficiência produtiva foi maior com ‘Portugal’ e ‘MC’ em todas as safras, exceto em 2011/12. O porta-enxerto Portugal induziu a maior produtividade em todas as safras, com exceção de 2011/2012, em que não houve diferenças entre os porta-enxertos. Os resultados da ASTT mostram visivelmente que os porta-enxertos ‘Inta 267’, D’Vranja e BA29 são mais vigorosos que MC e Portugal. Pode-se concluir que a produtividade de pereira ‘Carrick’ é maior com o porta-enxerto ‘Portugal’, o qual também reduz significativamente o vigor.
The study of 300 selections of Golden Delicious apple from plant material irradiated with gamma rays from a
60
Co source resulted in the final selection of two clones that represent an improvement of ...the original cultivar in reduced russetting in fruit stem cavity; greatly reduced tendency to biennial bearing; and slightly lowered fertility, an advantage in Golden Delicious which tends to overset. In a single-tree first trial, about 50% of the examined clones showed reduced pollen stainability; the majority of the semi-fertile mutants had 51 to 55% stainable pollen. The number of seeds per fruit was very closely related to pollen fertility. A close relationship was found among indicators of fruit maturity, that is, skin color, flesh color, soluble solids, and titratable acidity of fruit at harvest. More detailed measurements of 14 promising selections in a replicated second test revealed highly significant differences among clones in number of seeds per fruit, the incidence of russetting in the stem cavity, shape of fruit, skin color of fruit, flesh color of fruit, biennial bearing index, weight of fruit, and trunk cross-sectional area of the tree. Clonal differences were nonsignificant in yield ratings for a four-year period, and the yield for 1969 in kg per cm
2
of trunk cross-sectional area.
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