Fabiano Simões

How reliable is the double-ended pressure sleeve technique for assessing xylem vulnerability to cavitation in woody angiosperms?

The reliability of a double-ended pressure sleeve technique was evaluated on three woody angiosperm species with contrasting maximum vessel lengths. Vulnerability curves (VCs) were constructed by varying sample length and the size of the pressure sleeves. VCs were compared against curves obtained with reference techniques. For the two diffuse-porous species, Betula pendula and Prunus persica, VCs built with shoot segments shorter than maximum vessel length strongly overestimated species vulnerability. Furthermore, increasing the size of the pressure sleeve also tended to lead to overestimated VCs. For the ring-porous species Quercus robur, the technique strongly overestimated vulnerability to embolism, whatever the sample length or chamber tested. In conclusion, the double-ended pressure sleeve technique only gives reliable VCs on diffuse-porous angiosperms with short pressure sleeves, only when segments are longer than maximum vessel length.

Fenologia, brotação de gemas e produção de frutos de macieira em resposta à aplicação de cianamida hidrogenada e óleo mineral

ABSTRACT PHENOLOGY, BUDBREAK AND APPLE FRUIT PRODUCTION BY HYDROGEN CYANAMIDEAND MINERAL OIL APPLICATION The budbreak promoters application is one of main management strategies used to decrease theproblems of insufficient winter chilling on temperate fruit trees. Because the influence of budbreakpromoters on productive behaviour of plants, detecting this effects along of productive season becameimportant. Thus, this study was carried out during 2007/2008 season, in Cacador, Santa Catarina State,Brazil, aiming to evaluate different hydrogen cyanamide and mineral oil combinations on phenology,budbreak and apple fruit production. The experimental design was a randomized block, with sixreplications, in factorial arrangement (5x2), with five budbreak promoter treatments (1. control; 2. mineraloil 3.2%; 3. mineral oil 3.2% + hydrogen cyanamide 0.20%; 4. mineral oil 3.2% + hydrogen cyanamide0.39%; 5. mineral oil 3.2% + hydrogen cyanamide 0.59%) and two cultivars (Imperial Gala and Suprema´sFuji). The budbreak promoters application anticipated and reduced the blooming period, increasing theblooming overlap between Imperial Gala and Suprema´s Fuji cultivars. The budbreak promoters equalizedand increased the budbreak in axillary and terminal buds, with the major budbreak level observed inImperial Gala cultivar with 0.44% of hydrogen cyanamide and 3.2% of mineral oil treatment. The increaseof hydrogen cyanamide concentration showed the tendency to decrease the fruit set. It was observeddifferent treatment responses on production and mean fruit weight, probably to be related to fruitproduction predominance in different frutification structures.

Study of the Consequences of Global Warming in Water Dynamics During Dormancy Phase in Temperate Zone Fruit Crops

© 2012 Yamamoto et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Study of the Consequences of Global Warming in Water Dynamics During Dormancy Phase in Temperate Zone Fruit Crops

Dynamics of the water and carbohydrate content in branches of peach tree during the winter in the South Region of Brazil

O objetivo deste trabalho foi determinar o conteudo de agua e de carboidratos em ramos de pessegueiro durante o inverno, na regiao de Pelotas, no Rio Grande do Sul. Foram realizadas coletas quinzenais de ramos do ano de pessegueiros ‘Jubileu’ e ‘Eldorado’, entre os meses de junho e agosto/2010. Os ramos foram divididos em tres seccoes: basal, mediana e apical, sendo que para determinacao do conteudo de agua, estes foram divididos em dois tecidos: casca e lenho. Para o teor de carboidratos, foram analisados nas seccoes dos ramos o conteudo de acucares soluveis totais, sacarose e amido pelo metodo antrona. O conteudo de agua no tecido da casca nao mostrou alteracoes nas duas cultivares ao longo do periodo analisado. Verificou-se que a dinâmica do conteudo de agua e de carboidratos apresentaram um grande aumento principalmente na seccao apical do ramo proximo a brotacao. Conclui-se que a dinâmica do conteudo de agua e carboidratos podem ser considerados marcadores fisiologicos para a retomada do crescimento para frutiferas de clima temperado.