Consulta: subjectFacets:"Coffee tree"
Registros recuperados: 5
Data/hora: 09/06/2024 12:43:35

Estimation of total leaf area in perennial plants using image analysis
Provedor de dados: Revista Brasileira de Engenharia Agrícola e Ambiental
Autores: Marcon,Marlon; Mariano,Kleber; Braga,Roberto A.; Paglis,Carlos M.; Scalco,Myriane S.; Horgan,Graham W.
One feature of most horticultural crop plants that is biologically relevant to their yield and productivity is total leaf area. However, direct methods of estimation of the leaf area cause damage to the plants, whereas indirect methods such as based on light measurement, demand accuracy in the setup of the measurement procedure, which is specific to each crop. Coffee is one of the most important perennial plants related to worldwide trade, and this demands some ability to estimate the productivity of the crop, as well as all the perennial plants involved in production of agricultural products. This study aims to build a model based on indirect measures to estimate the leaf area in coffee plants using image analysis. Two models were evaluated, one based on...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Non-destructive method; Coffee tree; Model.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662011000100014

Effects of different drying rates on the physiological quality of Coffea canephora Pierre seeds
Provedor de dados: Brazilian Journal of Plant Physiology
Autores: Rosa,Sttela Dellyzete Veiga Franco da; Brandão Júnior,Delacyr da Silva; Von Pinho,Édila Vilela de Resende; Veiga,André Delly; Silva,Luiz Hildebrando de Castro e.
Desiccation tolerance in seeds depends on the species, development stage and drying conditions, especially the water removal rate. Coffea seeds are considered of intermediate performance, because they tolerate relative dehydration compared to orthodox seeds and are sensitive to low temperatures. The objective of this study was to verify the effect of different drying rates on the viability and storability of Coffea canephora seeds. A complete randomized experimental design was used, in a factorial 3 x 5 x 2 design, with three drying rates (fast, intermediate and slow), five final mean water contents after drying (51, 42, 33, 22 and 15 %) and two storage temperatures (10 and 20°C). The germination and seed vigor assessments, using radicle protrusion,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffee tree; Desiccation tolerance; Seeds; Seed storage.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000200002

Cold induced changes on sugar contents and respiratory enzyme activities in coffee genotypes
Provedor de dados: Ciência Rural
Autores: Partelli,Fábio Luiz; Vieira,Henrique Duarte; Rodrigues,Ana Paula Dias; Pais,Isabel; Campostrini,Eliemar; Chaves,Maria Manuela Coelho Cabral; Ramalho,José Cochicho.
The present research aimed to characterize some biochemical responses of Coffea canephora (clones 02 and 153) and C. arabica (Catucaí IPR 102) genotypes subjected to low positive temperatures, helping to elucidate the mechanisms involved in cold tolerance. For that, one year old plants were subjected successively to 1) a temperature decrease (0.5°C a day) from 25/20°C to 13/8°C (acclimation period), 2) a three day chilling cycle (3x13/4°C) and to 3) a recovery period of 14 days (25/20°C). In Catucaí (less cold sensitive when compared to clone 02) there was an increased activity in the respiratory enzymes malate dehydrogenase and pyruvate kinase. Furthermore, Catucaí showed significant increases along the cold imposition and the higher absolute values after...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffee tree; Coffea sp.; Sucrose; Enzymes; Cold stress.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782010000400006

Anatomic and physiological modifications in seedlings of Coffea arabica cultivar Siriema under drought conditions
Provedor de dados: Ciência e Agrotecnologia
Autores: Melo,Emanuelle Ferreira; Fernandes-Brum,Christiane Noronha; Pereira,Fabrício José; Castro,Evaristo Mauro de; Chalfun-Júnior,Antonio.
Due to the weather changes prognostic for the coming years, the understanding of water deficit and physiological responses of plants to drought becomes an important requirement in order to develop technologies such as mechanisms to assist plants to cope with longer drought periods, which will be essential to maintenance of Brazilian and worldwide production. This study aimed to evaluate ecophysiological and anatomical aspects as well as the nitrate reductase activity in Siriema coffee seedlings subjected to four treatments: Daily irrigated, non-irrigated, re-irrigated 24 hours and re-irrigated 48 hours after different stress periods. Non-irrigation promoted a reduction in leaf water potential being accented from the ninth day of evaluation onwards....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Coffee tree; Ecophysiology; Water stress; Nitrate reductase.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542014000100003

Source-sink manipulations in Coffea arabica L. and its effect on growth of shoots and root system
Provedor de dados: Ciência e Agrotecnologia
Autores: Alves,José Donizeti; Paglis,Carlos Maurício; Livramento,Darlan Einstein do; Linhares,Suellen Sarah Drumond; Becker,Frederico Biagi; Mesquita,Alessandro Carlos.
This paper investigated changes in growth and carbohydrate content of shoots and root systems in response to source-sink manipulation in field-grown coffee trees. The source-sink manipulations were carried out using manual de-fruiting. Two plots of trees were established: in one group, the fruit was left on the tree, while in the second group all fruits were removed manually. Similar results were obtained for coffee trees with and without fruit in terms of height, stem and skirt diameter and branch lengths. A biochemical evaluation of the roots showed that no differences were found between the levels of carbohydrates. In the leaves, levels of soluble sugars and reducing sugars were higher in plants with fruit. The starch concentration in leaves and roots...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Carbohydrates; Source-sink; Coffee tree; Root system.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542011000500013