Coffee Science - v.14, n.4, 2019

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/12725

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Resultados da Pesquisa

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    Impact of drying methods over the germinative potenti al of conilon coffee of late maturation
    (Editora UFLA, 2019-10) Posse, Sheila Cristina Prucoli; Rodrigues, Wagner Nunes; Comério, Marcone; Volpi, Paulo Sérgio; Verdin Filho, Abraão Carlos; Posse, Robson Prucoli; Oliveira, Vinicius de Souza; Arantes, Sara Dousseau
    This study aimed to evaluate the effect of different drying methods (regarding temperature and drying time) over the seed moisture and germination of seeds of Coffea canephora, harvested from genotypes of late maturation. For this end, seeds from selected genotypes were harvested and dried using two different methods: drying at 25 ˚C with natural circulation of air and drying at 35 ˚C with artificial circulation of air. The seeds were evaluated to quantify the loss of moisture content, and their germinative potential was assessed by parameters of germination speed, and the proportion of seedlings with healthy germination originated from them. The results show it is possible to apply different drying methods; using different systems, temperatures and times of exposure; to decrease the moisture content of seeds of C. canephora, from 50% (freshly harvested seeds from genotypes of late maturation, in July) to under 18% (dried seeds). Even if the initial stages of the drying process, while the seeds still present high moisture content, are similar for both methods, the method with artificial circulation of air at 35 ˚C promotes the drying speed and is able to achieve the lower levels of seed moisture using less than half of the time required by method with natural circulation of air at 25 ˚C. This faster moisture removal, however, has negative impacts over the germinative potential of the seeds, which are not observed for seeds subjected to the slow natural drying.
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    Microclimatic characterization of conilon coffee cultivate dinnorth-south alignment in northen Espírito Santo state, Brazil
    (Editora UFLA, 2019-10) Bis, Ana Paula Pereira; Partelli, Fábio Luiz; Rodrigues, Weverton Pereira; Falqueto, Antelmo Ralph; Espindula, Marcelo Curitiba; Martins, Lima Deleon
    The objective in this work was to study the influence of the North-South plantation alignment with respect to microclimatic, growth, and mineral nutrition conditions in order to quantify the variables and to point out possible consequences for the coffee tree. The experiment was carried out in a 6-year-old conilon coffee (Coffea canephora) crop with a mean height of 1.6 m, cultivated in full sun and spaced 3.5 m x 1.0 m. The data were collected on four dates from December 2016 to September 2017 in North Espírito Santo State, Brazil. The irradiance, air temperature, and vapor pressure deficit variables were quantified by means of external data loggers. The leaf temperature was determined by means of thermal images, and the plant growth and nutrient concentration in the leaves on both sides of the plant (East and West) were evaluated. The West side of the plant showed higher values of irradiance, temperature, and vapor pressure deficit in the afternoon, reaching a difference of 5°C between the two sides. The leaf temperature had similar behavior to air temperature, reaching a difference of approximately 12°C between the two sides in the afternoon. Although significant differences were observed for some nutrients between the sides of the plant, macro and micronutrient leaf contents remained within the range considered adequate for the coffee tree.