Periódicos
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
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Item Adaptations to the drought season and impacts on the yield of ‘Híbrido de Timor’ coffee tree in the Minas Gerais State Cerrado (Brazilian Savanna)(Escola de Agronomia - UFG, 2022-09-02) Santos, Cyntia Stephânia dos; Freitas, Ana Flávia de; Silva, Glauber Henrique Barbosa da; Carvalho, Milene Alves de Figueiredo; Santos, Meline de Oliveira; Carvalho, Gladyston Rodrigues; Silva, Vânia AparecidaClimate change threatens the survival of commercial crops due to their narrow genetic base. One of the alternatives is the identification of plants with potential for abiotic stress tolerance. This study aimed to verify the physiological and anatomical adaptations to the drought period and the impacts on the yield of ‘Híbrido de Timor’ coffee tree accessions. The experimental design was randomized blocks, in a 7 x 2 factorial arrangement, being seven genotypes (UFV 377-21, UFV 377-21, UFV 442-42, BE 5 Wush-Wush x UFV 366-08, UFV 428-02, UFV 376-31 and UFV 427-55) and two seasonal periods (dry and rainy), with two replications. The stomatal conductance; predawn water potential; levels of hydrogen peroxide and malondialdehyde; activity of the enzymes catalase, superoxide dismutase and ascorbate oxidase; ascorbate content; cuticle thickness of the adaxial surface and leaf lamina; stomatal density; ratio between polar and equatorial diameter; phloem area; area, diameter and frequency of xylem vessels; relative hydraulic conductivity; vulnerability index; and yield were evaluated. The results showed acclimatization of the accessions to the dry period, with some of them maintaining higher water potential values in the predawn; induction of the antioxidant system with the increase in the activity of the superoxide dismutase enzyme and ascorbate levels; increase in the cuticle and leaf lamina thickness; and a higher ratio between polar and equatorial diameters. Most of the evaluated accessions showed a good productive performance, especially the ‘UFV 377-21’, ‘UFV 442-42’ and ‘UFV 376-31’, with adaptations to the dry period and yield potential.Item Water retainer polymer in coffee plants deployment under different levels of irrigation(Editora UFLA, 2021) Resende, Thales Barcelos; Souza, Victor Hugo Silva; Castanheira, Dalyse Toledo; Carvalho, Milene Alves de Figueiredo; Guimarães, Rubens JoséThe use of water-retaining polymers may be a feasible alternative in regions with low water availability, as they has enhance the performance of coffee plants with more favorable anatomical characteristics to make physiological processes more efficient. However, the advantages of such use have been scarcely reported. Here, we studied the feasibility of using a water-retaining polymer to optimize irrigation water use during the establishment of a coffee plantation. A randomized block design was used in a factorial scheme (4 × 2) with three replications for a total of 24 experimental plots, each consisting of four pots, with one plant per unit. The experiment was installed in a greenhouse at the Coffee Science Department of the Universidade Federal de Lavras, Minas Gerais, Brazil, with four levels of irrigation (25%, 50%, 75%, and 100% of soil water at field capacity), with or without addition of the water-retaining polymer. Growth variables evaluated included: plant height, stem diameter, number of leaves, shoot and root dry weights, root volume and area. Additionally, gas exchange, leaf water potential, and leaf anatomy were analyzed. The use of water-retaining polymer during establishment of the coffee plantation ensured sufficient water supply, thus guaranteeing plant anatomical and physiological functionality and, consequently, a healthy, vigorous growth.Item Leaf anatomy, physiology and vegetative growth of fertigated Coffee arabica L. trees after exposure to pruning(Editora UFLA, 2021) Soares, Daiane dos Santos; Silva, Elisângela Aparecida da; Carvalho, Milene Alves de Figueiredo; Pereira, Fernanda Aparecida Castro; Guimarães, Rubens JoséIn coffee plants, fertigation can be an alternative way to minimize the negative effects exerted by drought and maximize fertilizer use efficiency. However, the fertilization recommendations for fertigated coffee trees are still not very specific, and the recommendations for rainfed crops are used. In addition, little is known about the nutritional requirements for fertigated coffee trees that have undergone the low recepa pruning treatment. Thus, the objective of this study was to evaluate the effects of different levels of nitrogen (N), phosphorus (P), and potassium (K) fertilizers on leaf anatomy, physiology, and veg etative growth of fertigated coffee trees (Coffea arabica L.) that have been under the low recepa pruning treatment. During the first five years of growth, the cultivar Topázio MG-1190 of the coffee crop received 10, 40, 70, 100, 130, and 160% of the fertilization levels recommended for the rainfed coffee crop. After this period, the crop was exposed to low recepa pruning. It was concluded that different doses of N, P, and K fertilizers modified the internal structure of coffee plant leaves, as well as physiological responses and plant growth; there was stronger vegetative growth, sharper leaf blade, greater thickness of spongy parenchyma, larger phloem area, and higher xylem relative hydraulic conductivity as the N, P, and K fertilizer levels in fertigated coffee (Coffea arabica L.) plants, which received the low recepa pruning treatment, increased. This knowledge can be used as a solid basis for main fertilization recommendations for fertigated coffee trees after exposure to the low recepa pruning treatment.Item Agronomic techniques for mitigating the effects of water restriction on coffee crops(Editora UFLA, 2019-01) Castanheira, Dalyse Toledo; Barcelos, Thales Resende; Guimarães, Rubens José; Carvalho, Milene Alves de Figueiredo; Rezende, Tiago Teruel; Bastos, Isadora dos Santos; Cruvinel, Arthur HenriqueWater restriction significantly affects coffee (Coffea arabica L.) production. The study of a few agronomic techniques that optimizes water use can generate technologies for mitigating the effects of climatic variations on coffee crops. The aim in this study was to indicate agronomic techniques that mitigate the effects of water restriction on coffee crops. For this end, we analyzed the morphophysiological changes in coffee plants cultivated in a greenhouse with different types of fertilizers and soil conditioners and under two levels of irrigation. The evaluations were performed 130 days after planting, assessing the morphological and physiological characteristics of the plants. We also quantified soil moisture in the different treatments. The water restriction expressively hindered plant growth. The use of controlled release fertilizers and soil conditioners, especially coffee husk, is indicated for mitigating water restriction in coffee crops.Item Big Coffee VL.: Seed desiccation tolerance, sieve classification, and physiological quality(Editora UFLA, 2018-10) Souza, Ana Cristina de; Rosa, Sttela Dellyzete Veiga Franco da; Vilela, Amanda Lima; Figueiredo, Madeleine Alves de; Vilela, Ana Luiza de Oliveira; Stéphano Filho, Ricardo; Carvalho, Milene Alves de FigueiredoA coffee plant producing large fruit, seeds, and leaves in relation to conventional coffee plants, possibly generated by genetic mutation, was named Big Coffee VL. Seeds of this coffee plant were classified by size and used to establish the crop, whose progenies were designated as Big Coffee VL. large, Big Coffee VL. medium, and Big Coffee VL. small. The aim in this study was to investigate desiccation tolerance, together with size classification, and evaluate the physiological quality of the seeds of this progeny. Seeds of each type of Big Coffee VL. and of the cultivar Topázio were collected. High moisture seeds and seeds dried to 11% moisture content were evaluated to assess desiccation tolerance. Dried seeds of each Big Coffee VL. progeny and of the Topázio cultivar were classified by size in sieve testing using oblong screens for separation of peaberry seeds, and circular sieves from 22 to 12 for separation of flat seeds. All seeds were subjected to physiological evaluation through the germination test and determination of seedling dry matter. A completely randomized experimental design (CRD) was used; results were subjected to analysis of variance and means compared by the Scott-Knott test. Big Coffee VL. seeds tolerate desiccation to moisture content of 11% wet basis. Seeds of the Topázio cultivar have better physiological performance than seeds of the Big Coffee VL progenies. The bigger the seeds of Big Coffee VL., the better their physiological performance, exhibiting greater seedling dry matter.Item Characterization of coffee cultivars leaf rust-resistant subjected to framework pruning(Editora UFLA, 2018-01) Reis, Estevam Antônio Chagas; Freitas, Tainah; Carvalho, Milene Alves de Figueiredo; Mendes, Antônio Nazareno Guimarães; Rezende, Tiago Teruel; Carvalho, João Paulo FelicoriThe goal of our work was to evaluate physiological and agronomic traits, as well as the relationship between these traits in coffee cultivars coming from a germplasm supposedly resistant to leaf rust, and their response to framework pruning. The experiment was conducted at the Federal University of Lavras in randomized blocks with three replicates, with spacing of 3.5 x 0.7 m and plots of 12 plants. An amount of 25 coffee cultivars was evaluated, from which 23 were considered resistant and two susceptible to leaf rust. Traits analyzed were the plagiotropic branch length and number of nodes, net photosynthetic rate, transpiration rate, water use efficiency, fluorescence and chlorophyll index, leaf area index, leaf rust incidence and yield. Catucaí Amarelo 20/15 cv 479, Araponga MG1 and Tupi IAC 1669-33 cultivars show highly responsive to framework pruning. These cultivars have high yield associated to high net photosynthetic rate, water use efficiency and low transpiration rate. Moreover, the last two cultivars show a low incidence of leaf rust. The Acauã cultivar has a good response to framework pruning, showing high yield associated to lower incidence of leaf rust. Catucaí Vermelho 785/15 cultivar is not responsive to framework pruning because show lower yield, high incidence of leaf rust, low vegetative growth and low water use efficiency.