Avaliação ecofisiológica da cultura da mangueira cv. Palmer em sistema agroflorestal

• Ano de defesa: 2023
• Autor(a) principal: Alves, Andressa Ferreira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Biologia Vegetal; Centro de Ciências Humanas e Naturais; UFES; Programa de Pós-Graduação em Biologia Vegetal
• Palavras-chave em Português: Agrofloresta; Fotossíntese líquida; Mangifera indica L.; Pigmentos fotossintéticos; Fluorescência da clorofila a; Agronomia
• Link de acesso: http://repositorio.ufes.br/handle/10/12710

The demand for food is increasing in the world and so are the impacts of conventional agriculture. Agroforestry Systems can be used to prevent soil degradation and increase soil infiltration while enhancing agricultural production. Chlorophyll a fluorescence has the potential to be a stress indicator evaluating the performance of plants grown in different cropping systems. Based on biophysical (chlorophyll a fluorescence) and biochemical (gas exchange, photosynthetic pigments) analyses, climatological data, and cultivation systems, it was possible to compare the two mango production systems and test the hypothesis that the cultivation of plants de Mangifera indica L. cv. Palmer in Agroforestry System provides greater resilience to climatic abiotic stresses such as temperature increase and prolonged dry periods. Five-year-old mango plants in the municipality of Aracruz - ES were used to carry out this experiment. Data collection was carried out monthly from August 2020 to January 2021. Analyzes of transient fluorescence of chlorophyll a, quantification of gas exchanges, chlorophyll indices and leaf pigments (chlorophylls a and b, and carotenoid pigments) were carried out. The experimental design was completely randomized (1x2), with mango plants submitted to 2 different cultivation systems (Agroforestry System x Conventional System) with 10 repetitions. Data were subjected to analysis of variance (ANOVA) and also applied to principal component analysis (PCA). The PCA showed that treatments differ occupying different quadrants. The OJIP curves obtained from both systems demonstrated that all plants were photosynthetically active. The formation of negative K, L, and G Bands may indicate a greater efficiency of the SAF treatment compared to the Conventional one. The high transpiration rate (E) and the stomatal conductance (gs), also higher than the conventional system, show that water availability and a reduction in temperature in the SAF microclimate may have allowed a greater opening of the stomata. Thus, the water use efficiency (W/E) was lower for the SAF due to the high transpiration rate, but the photosynthetic rate was slightly higher than the Conventional one. The high and significant index of total carotenoids in the SAF treatment may have contributed to photoprotection and reduced photosynthetic stress. It is possible that this water advantage has contributed to the increase in the index of photoprotective carotenoids that contributed to the reduction of photosynthetic stress in relation to the conventional system. The SAF System presented ecophysiological characteristics that indicate a greater photosynthetic efficiency than the Conventional System, more studies are needed to verify if this efficiency impacts productivity and fruit quality.