Efeito da temperatura durante a diferenciação de gemas, floração, crescimento e desenvolvimento de frutos em pessegueiro na região de Pelotas, RS.

• Ano de defesa: 2006
• Autor(a) principal: Couto, Marcelo
• Orientador(a): Raseira, Maria do Carmo
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Pelotas
• Programa de Pós-Graduação: Programa de Pós-Graduação em Agronomia
• Departamento: Faculdade de Agronomia Eliseu Maciel
• País: BR
• Palavras-chave em Português: Prunus persica; Adaptação climática; Biologia floral; Fertilização; Órgãos reprodutivos; Viabilidade de pólen
• Palavras-chave em Inglês: Climatic adaptation; Floral biology; Fertilization; Reproductive organs; Pollen viability
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA
• Link de acesso: http://guaiaca.ufpel.edu.br/handle/123456789/2122

Insufficient chilling accumulation limits the production of peach in subtropical areas. Comparatively this combined with the wide temperature fluctuation during bud differentiation, through the bloom period and fruit growth and development may cause crop losses. Problems with low productivity in southern Rio Grande do Sul often attributed to the mild winter conditions, however, the environmental conditions especially around bloom period to be critical for optimal yields. In subtropical áreas temperature oscillations may cause problems during fertilization with subsequent reduction of fruit set and production instability of some peach cultivars. To better understand the effect of high temperatures on flower differentiation, pre-blooming, blooming, fruit set and fruit development and growth observations were made during the stages of bud differentiation, leafing and blooming, which included pollen production and viability, floral morphology, fruit set and the fruit growth and development. Temperature elevation with the tree was obtained by bagging branches with transparent plastic or with transparent plastic bottles. Plants of two low chilling peach cultivars (200 to 300 hours): Granada and Maciel were used in the years of 2003, 2004 and 2005. Conditions of high temperatures during the period of bud differentiation of Granada and Maciel did not promote the formation of double pistils or any morphologic anomalies. Bagging shoots with transparent plastic bags and plastic bottles is a simple and economical way of increasing the temperature on the branches under field conditions. High temperatures conditions during pre-blooming period advanced and accelerated the flowers anthesis and pistil growth. Flower morphology, regarding pistil length and weight, was not influenced by temperature elevation under experimental conditions. High temperatures during the pre-blooming negatively influenced the fruit set of the peach cultivar Granada. The percentage of in vitro pollen germination was different among cultivars and incubation temperatures. Pollen viability of cultivars Esmeralda, Granada, Jade and Maciel, can be evaluated by in vitro germination in standard culture medium (10% of sucrose + 1% of agar, dissolved in distilled water), three hours after the inoculation, with incubation at 24°C and 28°C. Under high temperatures conditions during the stage I of fruit growth and development of peach cultivars Granada and Maciel, cell division may be accelerated since a larger number of cells was counted in the pericarp tissue.