Pesquisa Agropecuária Tropical
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/13103
Navegar
8 resultados
Resultados da Pesquisa
Item Effect of fruit load of the first coffee harvests on leaf gas exchange(Escola de Agronomia - UFG, 2021-01-14) Muñoz, Carlos Andres Unigarro; Bejarano, Lina Marcela Díaz; Acuña, José RicardoCoffee production between the first and second harvest presents a difference in the fruit load with the plant age that could affect the leaf gas exchange. This research aimed to evaluate the effect of the increase in fruit load that occurs between the first and second harvest of the Coffea arabica L. production cycle on the measured gas exchange, at the two phenological stages of the fruit. The accessions E057, E318, E338 and E554 were used, as well as a completely randomized design, with three replications, using the accessions as treatments and the harvest measurements during the production cycle as the repeated measures. The variables yield per tree, number of fruits, absolute growth rates for height and stem, leaf area, leaf-to-fruit ratio and leaf gas exchange were measured across the phenological stages of fruit filling and ripening. The increase in the fruit load that occurs with age in the second harvest, if compared to the first harvest, showed a positive and significant effect on the net assimilation rate that was not expected for the obtained leaf-to-fruit ratios. Likewise, the differences in the assimilation rates were higher during the fruit-filling stage. This result suggests that the source-sink relationship may vary with the crop age and fruit phenological stage, and is not entirely depend on the leaf-to-fruit ratio.Item Assessment of leaf anatomic and physiological characteristics and genetic divergence among Coffea arabica L. cultivars in the Brazilian Savanna(Escola de Agronomia - UFG, 2022-01-16) Santos, Cyntia Stephânia dos; Pereira, Fernanda Aparecida Castro; Mauri, Janaína; Viana, Mariana Thereza Rodrigues; Rodrigues, Gustavo Costa; Veiga, Adriano Delly; Bartholo, Gabriel Ferreira; Carvalho, Milene Alves de FigueiredoThe knowledge on cultivars is essential for parental choosing on breeding programs. This research aimed to study the genetic divergence of Coffea arabica L. cultivars from a germoplasm bank of the Embrapa Cerrados, Brazil, for leaf anatomic and physiological characteristics. A total of 23 cultivars were evaluated: Acaiá Cerrado MG1474, Araponga MG1, Catiguá MG1, Catiguá MG2, Catiguá MG3, Catiguá MG3 P4, Catiguá MG3 P5, Catiguá MG3 P7, Catiguá MG3 P9, Catiguá MG3 P23, Catiguá MG3 P51, Catuaí Amarelo IAC 62, Catuaí Vermelho IAC 15, Catuaí Vermelho IAC 81, Catuaí Vermelho IAC 99, Caturra Vermelho MG0187, Guatenano Colis MG0207, Mundo Novo IAC 379-19, Paraíso MG1, Pau Brasil MG1, Sacramento MG1, San Ramon MG0198 and Topázio MG1190. In addition to the genetic divergence, the broad sense heritability and coefficient of genetic and environmental variation were also evaluated. All characteristics showed high coefficients of genetic variation and heritability values greater than 70 %, indicating a predominance of genetic over environmental factors, and that these are characteristics likely to obtain genetic gain. Catiguá MG1, Catiguá MG3 P51 and Topázio MG1190 stood out, with superior gas exchange characteristics. Attributes related to gas exchange were important for cultivar differentiation, demonstrating that they can be used in the early selection of Coffea arabica L. genotypes.Item Mycorrhizal effects on glomalin-related soil protein and chlorophyll contents in coffee plants in the Peruvian Amazon(Escola de Agronomia - UFG, 2022-03-21) Solis, Reynaldo; Vallejos-Torres, Geomar; Arévalo, Luis; Caceres, BenjaminThe inoculation of vegetatively propagated coffee plants with arbuscular mycorrhizal fungi (AMF) prior to field establishment may positively influence the plant growth and physiology. This study aimed to evaluate the AMF effects on the glomalin-related soil protein and chlorophyll contents in vegetatively propagated coffee plants inoculated in a greenhouse and transplanted to an open field, in the Peruvian Amazon. The experiment consisted of eight treatments, in a 2 × 4 factorial design, being two coffee varieties (Caturra and Pache) and four AMF inocula (control, Moyobamba, El Dorado and Huallaga). The inocula were collected from organic coffee crops and named according to the province from which they were collected. The mycorrhizal colonization and chlorophyll content were statistically higher in the plants inoculated with AMF, if compared to the non-inoculated plants, while the glomalin-related soil protein content ranged from 61.6 to 69.1 mg g-1 and showed no statistically significant differences among the inocula, although the Moyobamba inoculum showed to be numerically superior. The effect of the coffee variety was not statistically significant among the variables under study.Item Early selection of drought-tolerant Coffea arabica genotypes at the seedling stage using functional divergence(Escola de Agronomia - UFG, 2022-08-15) Reis, André Moraes; Mendes, Antônio Nazareno Guimarães; Abrahão, Juliana Costa de Rezende; Santos, Meline de Oliveira; Silva, Vânia AparecidaThe development of more drought-tolerant cultivars is essential for the maintenance of global agricultural production. This study aimed to perform an early selection of drought-tolerant Coffea arabica genotypes by evaluating their functional divergence using morphological, anatomical and physiological analyses. Seedlings of 14 genotypes were subjected to the drought stress imposed by irrigation for 18 days. Growth and anatomical parameters, leaf water potential and gas exchanges were measured. Under irrigated conditions and prolonged drought (18 days), the divergence among the genotypes was determined mainly by morphological traits, such as leaf area, stem diameter and, consequently, shoot dry mass. Under moderate drought (14 days), parameters such as water potential, cuticle thickness, stomatal density, number of xylem vessels and water-use efficiency were important for the divergence of the group with the highest ability to maintain its water status. The genotypes 1, 2, 4, 11 and 12 have characteristics that contributed to the maintenance of water status, such as greater cuticle thickness, stomatal density, smaller number of xylem vessels and phloem thickness, bigger root length and greater water-use efficiency. The functional divergence combining morphological, anatomical and physiological analyses in response to the moderate drought indicated the early selection of the genotypes 1, 2,4, 11 and 12 as more drought tolerant during the seedling stage.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 Spray technology for deposition of droplets on coffee leaves and fruits(Escola de Agronomia - UFG, 2021) Zampiróli, Renan; Alvarenga, Cleyton Batista de; Parenti, Matheus Vilhena; Cunha, João Paulo Arantes Rodrigues da; Celoto, Fernando Juari; Rinaldi, Paula Cristina Natalino; Sasaki, Robson ShigueakiPara o sucesso do controle fitossanitário no cafeeiro, é importante uma correta deposição de calda ao longo do dossel. Contudo, a estrutura da planta dificulta essa distribuição. Objetivouse avaliar a deposição de um traçador em folhas e frutos, na cultura do café, em função da taxa de aplicação e do tipo de ponta de pulverização, bem como do emprego de um sistema de pulverização eletrostática. Utilizou-se pulverizador hidropneumático com pontas hidráulicas de jato cônico vazio, da série TVI (gotas grossas com indução de ar) e JA (gotas finas), em taxas de 200 e 400 L ha-1. Também foi avaliado um sistema eletrostático, com ponta SPE-2 e taxa de 200 L ha-1, instalado no mesmo pulverizador. Foram determinadas a deposição do traçador em folhas e frutos dos terços superior, médio e inferior das plantas, bem como as perdas para o solo na projeção da copa, mediante quantificação por espectrofotometria. Os resultados indicaram que a aplicação eletrostática proporciona maior deposição nas folhas do terço superior, em relação à aplicação hidropneumática, independentemente da taxa de aplicação. A ponta TVI produz maior deposição nos frutos do terço médio e maior perda para o solo, em relação à ponta JA. A taxa de aplicação de 400 L ha-1 promove maior deposição nos frutos do terço médio, em relação à de 200 L ha-1, mas também causa maior perda para o solo.Item Adsorption isotherms and isosteric heat in Coffea arabica beans(Escola de Agronomia - UFG, 2020) Santos, Samuel Gonçalves Ferreira dos; Silva, Daniel Pereira da; Sarti, Jefferson Kran; Almeida, Vinícius Gonçalves; Rodovalho, Renato SouzaO conhecimento do equilíbrio higroscópio de adsorção em café é pertinente para a adequação de seu armazenamento, garantindo a qualidade do produto até o consumidor final. Objetivouse determinar as isotermas de adsorção de grãos de café Arábica (cultivar Acauã Novo) nas temperaturas de 30 ºC, 40 ºC, 50 ºC e 60 ºC, bem como o calor isostérico integral de adsorção. Os teores de água de equilíbrio foram obtidos pelo método estático gravimétrico, com atividades de água entre 0,10 e 0,83 (decimal). A partir dos dados obtidos, foram ajustados diversos modelos matemáticos para representar as isotermas de adsorção. Os critérios estatísticos para a seleção do melhor modelo foram o coeficiente de determinação, erro médio estimado, erro médio relativo e a distribuição de resíduos. O modelo de Peleg foi o que melhor representou as isotermas de adsorção dos grãos de café Arábica nas condições estudadas. As isotermas apresentaram formato sigmoidal tipo II. Sob atividade de água constante, o aumento da temperatura promove diminuição no equilíbrio do teor de umidade em grãos de café Arábica. Os valores de calor isostérico com teor de água entre 0,0191 e 0,2534 (base seca) variaram de 4.042,19 kJ kg-1 a 2.395,48 kJ kg-1.Item Effects of mycorrhizal association and phosphate fertilization on the initial growth of coffee plants(Escola de Agronomia - UFG, 2020) Araújo, Fausto Henrique Vieira; Cruz, Rafaele de Souza; Porto, Douglas William Batista; Machado, Caroline Maíra Miranda; França, André CabralNa implantação de lavouras cafeeiras, a adubação fosfatada é um dos manejos de fertilidade do solo mais importantes. Visando minimizar perdas, dentre as opções em uso estão os adubos de liberação lenta de nutrientes, consorciados à inoculação de fungos micorrízicos arbusculares (FMA). Objetivou-se avaliar o crescimento inicial de cafeeiro inoculado com FMA e submetido a diferentes tipos de fertilizantes fosfatados. O experimento foi conduzido em casa-devegetação, utilizando-se delineamento experimental em blocos ao acaso, em esquema fatorial 2 x 4, com quatro repetições. O primeiro fator consistiu de presença ou ausência de FMA (Rhizophagus clarus) e o segundo de fertilizantes fosfatado [monoamônio fosfato (MAP)], organomineral peletizado, organomineral granulado e controle (sem adubação). Avaliaram-se a altura de planta, teor de clorofila nas folhas, número de ramos plagiotrópicos, área foliar, massa da matéria seca da parte aérea e do sistema radicular, porcentagem de colonização de raízes e fósforo foliar. A inoculação com FMA, associada ao fertilizante organomineral peletizado, proporcionou maior crescimento da parte aérea e do sistema radicular e maiores teores de fósforo, em relação aos demais tratamentos, podendo ser uma alternativa na implantação ou renovação de lavouras cafeeiras