Revista Ceres

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/9884

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Resultados da Pesquisa

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    Agronomic performance of Arabica coffee cultivars in the subtropical humid environment of Vale do Ribeira Paulista, Brazil
    (Universidade Federal de Viçosa, 2022-01-09) Carvalho, Alex Mendonça de; Teramoto, Érico Tadao; Botelho, Cesar Elias; Carvalho, Gladyston Rodrigues; Lima, Amador Eduardo de; Guerreiro Filho, Oliveiro
    This research is related to the evaluation of vegetative growth parameters, initial yield and incidence of pests and diseases of twelve Arabica coffee cultivars submitted to the subtropical humidity environment of Vale do Ribeira Paulista, Brazil. The experiment was performed in the Experimental Campus of the UNESP in Registro, in a randomized block design, with three replications. Stem diameter, number of plagiotropic branches, plant height, number of internodes of plagiotropic branches, length of the first plagiotropic branch, incidence of brown eye spot and phoma leaf spot on coffee leaves, infestation by leaf miner and the yield of cultivars were evaluated. The results obtained allowed to conclude that: i) cultivars Catuaí Amarelo IAC 62, Catuaí Vermelho IAC 99 and Mundo Novo IAC 379-1 were higher than the others, with yield above the national average in 2020 and percentage of flat beans below 10%; ii) all cultivars evaluated showed a similar level of increment of variables that indicate plant growth and reproductive development; iii) the cultivation environment is favorable to infestation by the leaf miner and unfavorable to the incidence of rust; iv) The prevailing climatic conditions in the Vale do Ribeira Paulista is suitable for the production of Arabica coffee.
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    Digital imaging of coffee leaves under different nitrogen concentrations applied to soil
    (Universidade Federal de Viçosa, 2022-01-09) Godoy, Leandro José Grava de; Carvalho, Alex Mendonça de; Freitas, Ana Flávia de; Botelho, Cesar Elias; Garibaldi, João Luís Teodoro; Ferrari, Samuel
    Brazil is the largest Coffea arabica L. producer and exporter in the world market. In view of the need for nitrogen fertilization, the objective of this work was to evaluate the use of digital images of coffee leaves as a function of nitrogen concentration and cultivars, as well as to evaluate the most adequate sampling of this technique to predict leaf nitrogen. The experiment was set in a greenhouse, at UNESP - Experimental Campus of Registro-SP, using 12L pots with medium sand. A completely randomized design was adopted, in a 4 x 2 factorial scheme, with four concentrations of N (0, 50, 100 and 200 mg dm-3), and two coffee cultivars (Mundo Novo and Obatã), with ten replications. The variables evaluated were: hue, dark green color index (DGCI), leaf area and leaf nitrogen content. The hue and DGCI were influenced by N concentration, cultivar and are dependent on the day after treatment application and the number of leaves used. The use of five leaves per replication was more adequate to estimate leaf N content. Hue, DGCI and leaf area were higher in Obatã depending on the day after application of the treatment and N concentration.