Influência do déficit hídrico na floração do cafeeiro arábico, monitorado pelo desenvolvimento do botão floral e potencial hídrico da planta

• Autor(a) principal: Bomfim Neto, Hermes
• Data de Publicação: 2007
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3505
• topic: Café; Deficit hídrico; Floração; Coffee; Water deficit; Flowering; CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA::ENGENHARIA DE AGUA E SOLO

It was aimed to evaluate criteria for the flora control and uniforming of the irrigated coffee plant, submitted to water deficit, in function of the development of the floral button and of the water potential of the plant in the dawn. For that, two experiments were carried out, in the period from June 2006 to May 2007, with coffee plants (Coffea arabica L. cv. Catuaí 144) irrigated by leak, cultivated in the spacing of 3,8 x 0,5 m, with approximately 4,5 years of age, in Luís Eduardo Magalhães (12nd 5´S, 45th 48´W), B in an altitude of 760 m in soil classified Quartzsandy Neosoil of medium texture. It settled down as criterion to begin the water deficit, in both experiments, the development of the floral buttons, and the experiment 1 had the period of the water deficit monitored through the development of the floral button and the experiment II, through the water potential of the plant in the dawn. To accomplish the handling of the irrigation and to characterize the influence of the climatic elements on the behavior of the floral button of the plants of coffee, an automatic meteorological station was settled, with sensors that supply data temperature diaries, relative humidity, speed of the wind, solar radiation and precipitation. Besides those varieties, it was determined the deficit of steam pressure. Starting from the data of the station, the handling of the irrigation was managed by the software IRRIPLUS Ò, determining the water demand of the culture, evaluating the water daily , using the coefficients of adjustments on ETo. It was defined like this the water depth, in function of the difference between water demand and the effective precipitation. To evaluate the flora uniformity, maturation of the fruits, growth and productivity of the coffee plant, periodically, the following variables were evaluated: number of flowers emitted by branch in each bloomed; number of ties accumulated every month; percentage of green fruits, cherry and raisin in the moment of the crop; income; it sifts average and production of fruits. The data were submitted to the variance analysis and the compared averages being used of the test of Tukey, P = 0,05. For the other characteristics the descriptive analysis was used. The maturation uniformity was reached starting from the moment that the floral buttons were synchronized at the stadium 4 of development and with the water potential in the down below -1,2 MPa. However, the flora uniformity, allied the maturation of the fruits, without decrease in the productivity, it was only reached in the plants of the treatments that bloomed before the incentive to the opening of the floral button provoked by the change in the behavior of the climatic elements. It was not verified, at the end of the agricultural year, difference among the cumulative number of ties for all the plants of the treatments of both experiments. It was verified, in that way, that the use of the water deficit is an efficient tool to uniformize adorned and maturation of the fruits of the coffee plant, however, the same should be imposed carefully, taking into account the synchronization of the floral buttons, the magnitude of the water deficit and the behavior of the climatic elements.