Doralice Lobato de Oliveira Fischer

Efeito do ácido indolbutírico e da cultivar no enraizamento de estacas lenhosas de mirtilo

Dentre os metodos de multiplicacao do mirtilo, a propagacao por meio de estacas e uma tecnica de baixo custo, que proporciona resultados variaveis, de acordo com a cultivar e outros fatores. Objetivou-se, com este trabalho, avaliar o efeito do AIB no enraizamento de estacas lenhosas de mirtilo das cultivares Powderblue, Delite, Climax, Bluebelle e Woodard. O material vegetativo utilizado, oriundo de matrizeiro, constituiu em segmentos de ramos principais, com 15 cm de comprimento e diâmetro aproximado de 6 mm. Apos o preparo das estacas, as bases das mesmas foram imersas, por 15 segundos, em uma solucao com fitorregulador (AIB), nas concentracoes de 0; 1.000; 2.000; 4.000 e 8.000 mg.L-1 , sendo colocadas para enraizar em areia de granulometria media, sob irrigacao intermitente, por microaspersao. O delineamento experimental foi em blocos ao acaso, com quatro repeticoes e dez estacas por parcela. Apos oito meses da instalacao do experimento, avaliaram-se a porcentagem de estacas enraizadas, o numero medio de raizes por estaca, o comprimento da maior raiz, o numero medio de brotacoes e o comprimento da maior brotacao. A resposta das diferentes cultivares de mirtilo ao enraizamento das estacas variou com a concentracao de acido indolbutirico (AIB). Independentemente do uso de AIB e da cultivar, na maioria dos tratamentos, a porcentagem de enraizamento foi superior a 55%.

Enraizamento de estacas semilenhosas de mirtilo sob o efeito de diferentes concentrações de ácido indolbutírico

Blueberries can be propagated by a variety of methods such as seeds, suckers, micropropagation and cuttings. Commercially, most propagation is done by cutting, providing different results depending on the cultivar. Thus, the objective of this research was to evaluate the indolebutyric acid (IBA) effect on rooting of semi-hardwood cuttings of blueberry cultivars Delite and Bluebelle collected on December/2005. Four-node segments with 6 mm approximately, containing 2 upper leaves cut in half were taken from main branches of irrigated plants. After preparation, the cuttings were treated with IBA at 0, 1000, 2000 or 4000 mg L-1 , and immediately inserted into rooting media (washed thick sand) under intermittent micro-sprinkler irrigation. The experimental design was a complete randomized block with four replications of ten cuttings. A hundred and twenty days after the experiment installation, Bluebelle provided large number and length of both roots and shoots, and had a rooting percent of 37.5%, whether applying IBA at 1000 mg L-1. The cultivar Delite showed high facility to emit roots and shoots, regardless to IBA presence, showing more than 82.5% of rooted cuttings.

Enraizamento de estacas lenhosas de três cultivares de mirtileiro com diferentes concentrações de AIB

Commercially, propagation of blueberry by cutting is the very usual method, which gives a range of results according to the cultivar. This research aimed to evaluate the effect of indol-butyric acid (IBA) on rooting of blueberry hardwood cuttings. It was used segments of secondary branches with four buds and mean diameter of 4.5mm. The experimental design was totally randomized in a 5x3 factorial, five concentrations of IBA (0; 1500; 3000; 4500 and 6000mg L-1) and three cultivars (Delite, Bluebelle and Briteblue). It was used four replications and ten cuttings per plot. After cutting, the base of the cuttings was dipped for 10 seconds into a solution of IBA. Then, they were put to root in a mix of thick sand and commercial substrate Turfa Fertil® (1:1) with pH 5.5 and manually irrigated. After 138 days from trial installation, percentage of rooted cuttings, number of root per cutting, length of the largest root, number of shoots, length of the largest shoot and percentage of surviving cuttings were evaluated. According to the results it was not verified interaction among different factors. It was verified difference among cultivars only in the length of the largest root, number of root per cutting and percentage of surviving cuttings. For concentration of IBA, it was verified by regression analysis, a linear behavior for the variables increasing rooted and survived, but the response was quadratic for the longest root length. It was concluded that the concentration up to 6000mg L-1 IBA is not sufficient to express the maximum rooting potential of the blueberry cuttings cultivars Delite, Bluebelle and Briteblue.

Emergência de plântulas de porta-enxertos de pessegueiro submetidos a diferentes períodos de estratificação

RESUMO - Objetivou-se com este trabalho, avaliar a germinacao e o desenvolvimento de plantas oriundas de duas cultivares de pessegueiro ‘Capdeboscq’ e ‘Okinawa’ sob diferentes periodos de armazenamento, em viveiro comercial da empresa Frutplan Mudas Ltda, em Pelotas - RS, no periodo de maio a dezembro de 2009. Os carocos das duas cultivares foram armazenados em embalagens de papel por um periodo de 120 dias, sendo realizados os seguintes procedimentos: 10 dias de temperatura ambiente + 110 dias de frio; 40 dias de temperatura ambiente + 80 dias de frio; 70 dias de temperatura ambiente + 50 dias de frio; 100 dias de temperatura ambiente + 20 dias de frio e 120 dias de temperatura ambiente. Utilizando câmara fria programada para 6 ± 2 °C. O experimento foi conduzido em blocos casualizados, com quatro repeticoes e 25 sementes por parcela, no arranjo fatorial 2x5 (duas cultivares e cinco periodos de estratificacao). As variaveis analisadas foram: porcentagem de plântulas emergidas, altura das plantas, diâmetro do tronco medido a 10 cm do colo, indice de velocidade de emergencia em campo (IVEC) e dias para obtencao de 70% de emergencia. A emergencia da cv. Okinawa foi proximo a zero, com isto nao foi considerada para avaliacao de plântulas. Para a cv. Capdeboscq verificou-se diferencas significativas apenas para a variavel dias para obtencao de 70% de emergencia de plântulas, 112 a 123 dias, exceto para o tratamento com maior horas de frio que nao atingiu os 70% de emergencia. Conclui-se que os periodos de estratificacao e frio nao se mostraram vantajosos para obtencao de porta-enxertos de pessegueiro destas cultivares nas condicoes em que foi conduzido o experimento. Palavras-chave: Pessegueiro. Armazenamento. Germinacao.

Seleção de genótipos de mirtileiro obtidos a partir de polinização aberta

Blueberry cultivars economically grown in Brazil were introduced from other countries, in which they were selected according different edaphoclimatic conditions and so it might impose some cultivation limitation in Brazil. In order to obtain superior progenies better adapted to Brazilian conditions, it was performed plant selection in three free polinization blueberry populations. The plant material consisted of 3,554 plants obtained from seeds from the cultivars Bluegem (1,212 plants), Bluebelle (1,439 plants) and Powderblue (903 plants). The experiment was performed in an area previously fertilized according to soil analysis, in a spacing of 30 x 30 cm, with sprinkler irrigation system. The selection was performed during three growing seasons (2007/08, 2008/09 and 2010/11). In the first growing season it was made a negative selection, eliminating the undesirable plants; in the second, a positive selection was performed, where 20 plants were selected from each of the populations; and the third, also by positive selection, where ten plants were selected within each set of 20 plants previously selected in the second step. As the selection criteria, it was used the following characteristics for the first two growing seasons: plant vigor, production, plant health, early production, presence of bloom, fruit size and fruit flavor, the latter assessed by two trained individuals. At the end of the second growing season, the pre-selected 20 plants of each population were evaluated for a period of two years (2009/10 and 2010/11), recording productive parameters of these plants and chemical parameters of the fruits. The subjective consideration of these outcomes was an additional criterion used for the selection of the third growing season plants. It was noticed that the genotypes of the three cultivars of this study show yield and fruit size suitable to the market. Moreover, genotypes derived from the cultivars Bluegem and Powderblue have better sugar/acidity relationship. Based on the results obtained, it can be concluded that the genotypes BG5, BG2, BG3, BG6, PW3, PW5, PW1, BB10, BB2 and BB5 have the potential to continue the selection process, since they have good vegetative growth, fruit good quality and size appropriate to the consumer market.