Crescimento e variações diurnas da fotossíntese de genótipos de Coffea canephora cultivados à campo sob condições contrastantes de disponibilidade de luz

• Autor(a) principal: Souza, Dinorah Moraes de
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/7840
• topic: Shading; Conilon; Phenotypic plasticity; Sombreamento; Conilon; Plasticidade fenotípica; Melhoramento Vegetal; Café - Cultivo; 631.523

Coffee is a tropical perennial crop of extreme importance for global agribusiness. It is usually grown in regions potentially subject to stress especially thermal, water and nutritional. During the crop cycle, limiting conditions are accentuated during the reproductive growth period, leading to significant decline of crop yields, and leading to significant decline of crop yield. Shading Systems (Trees), while providing sensitive changes in microclimate, it can minimize the adverse climate effects on crops. Therefore, the objective of this study was to evaluate the growth and diurnal variations of genotypes photosynthesis of coffea canephora cultivated in field under contrasting conditions of light availability. The study was conducted in field conditions in the municipality of Alegre-ES. The experiment was set up by combining four clones of coffea canephora (02, 48, 83 and 153) of the array clonal “Conilon Vitória- Incaper 8142” with two levels of light availability [0% (full sunlight) and 30% of shade], totaling eight treatments, with five replicates. Growth evaluation were held in plagiotropic branches from the middle third of plants, selected in the flowering stage and evaluated until the ripening of the fruits. Diurnal variation of the parameters of gas exchange and chlorophyll a fluorescence were carried out in three periods throughout the day: 09, 12 and 15h during the filling phase. Clone 02 presented superior performance under full sun conditions, with photosynthetic rate higher than average, normally described for the species (approximately 16 ?mol m-2 s-1). Clone 48 had a better performance under shade because it maintained higher photosynthetic rates throughout the day. This allowed the balance between the photoassimilates investment, necessary to meet the demand of vegetative growth and management of fruit growth, consequently, presenting lower abortion rates and higher numbers of fruits per rosettes.