Tolerância diferencial e eficiência nutricional de café arábica em relação à deficiência de zinco

• Autor(a) principal: Pedrosa, Adriene Woods
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4493
• topic: Coffea arabica; Zinco; Eficiência nutricional; Micronutrientes; Deficiência; Coffea arabica; Zinc; Nutritional efficiency; Micronutrients; Deficiency; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA

Coffee is a micronutrient demanding plant, especially of zinc. In this research, the Zn lack differential tolerance and the Zn nutritional efficiency of coffee varieties were verified as zinc deficiency is applied. Also, the zinc influences on plant grow and development, as well as its influence on some biochemical features, was studied. Thus, 11 C. arabica varieties were cultivated in nutritive solution as the treatments were 0,0 and 6,0 µmol L-1 of zinc, for eight months. The experiment was carried out in a greenhouse using the Clarck solution. The treatments were established in a factorial 11x2 (11varieties and two treatments of zinc) scheme, in a completely randomized design, with three replications. After that, the plants were collected and separeted by leaves (apical, newly mature and basal), stems and roots, to determine dry matter production and the concentration of total and active zinc. The absorption efficiency, foliar biomass production efficiency, biomass production efficiency, Zn utilization efficiency and zinc content were calculated from the data of zinc concentration and dry matter accumulated on the different parts of the plant. The SPAD index was measured on the apical and newly matured leaves. The concentration of chlorophyll a; b, and total, carotenoids, indol compounds, and superoxide dismutase activity were analyzed from the second pair of newly mature leaves from the plagiotropic branches. The concentrations of zinc used affected the dry matter production, as well as the zinc plant concentratin and consequently the plant efficiency on absorb and utilize zinc. SPAD index, the concentration of chlorophyll a, b and total, carotenoids, indolic compounds and superoxide dismutase activity also were affected by the Zn concentration of the nutritive solution. Zinc deficiency affected the development of all coffee varieties studied in this experiment. Dry matter production of the apical leaves was the most affected by zinc concentration leading the plants to a large variability of responses among the varieties studied. San Ramon and São Bernardo showed to be the most sensitive to the lack of zinc, and presented a low zinc utilization efficiency on the two Zn doses studied. IPR-102 and Rubi were the less sensitive to zinc lack. However, Rubi showed to be sensitive to the dose 6,0 µmol L-1 of Zn. The other varieties studied such as Acaiá Cerrado, Caturra Amarelo, Catucaí Vermelho, Paraíso, Topázio and Tupi presented intermediate response to the lack zinc. Oeiras variety showed to be sensitive to the lack of zinc, despite of its high efficiency to absorb the nutrient. The differential tolerance of zinc was mainly influenced by the different capacity of absorption and translocation of zinc of each variety studied.