Periódicos

URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352

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Resultados da Pesquisa

Agora exibindo 1 - 2 de 2
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    Modifications on leaf anatomy of Coffea arabica caused by shade of pigeonpea (Cajanus cajan)
    (Instituto de Tecnologia do Paraná - Tecpar, 2004-11) Morais, Heverly; Medri, Moacyr Eurípedes; Marur, Celso Jamil; Caramori, Paulo Henrique; Ribeiro, Ana Maria de Arruda; Gomes, José Carlos
    Modifications on leaf anatomy in Coffea arabica shaded with pigeonpea (Cajanus cajan), compared to cultivation under full sun, were assessed. The leaves fully exposed to sunlight presented thicker cuticles and cellular walls, narrower epidermis cells, palisade parenchyma with longer cells, thicker lacunar parenchyma, fewer intercellular spaces and a larger stomata number. Leaves under dense shade presented a narrower cuticle and cellular wall; a mesophyll with smaller volume, but with larger intercellular spaces; and epidermis with thicker cells and a smaller stomata amount, surrounded by subsidiary cells of smaller dimensions. Plants grown under full sunlight presented higher values of net photosynthesis. The results evidenced that the species C. arabica has a wide range of phenotypic adaptation to changes in the radiation intensity.
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    Effect of leaf water potential on cold tolerance of Coffea arabica L.
    (Instituto de Tecnologia do Paraná - Tecpar, 2002-12) Caramori, Lázara Pereira Campos; Caramori, Paulo Henrique; Manetti Filho, João
    Young coffee plants from cultivar Mundo Novo of Coffea arabica were grown without irrigation for 32 consecutive days, to evaluate the effect of leaf water potential on damage caused by low temperatures, under controlled conditions. À wide range of leaf water potentials were evaluated, from — 0.45MPa (wet soil) at the beginning of the experimental period, to — 4.8MPa (severe leaf wilting) at the end. Results showed that under moderate water stress, there was a higher frequency of undamaged plants and lower frequency of severely damaged plants. These results help explain part of the regional variability observed after a frost and stress the importance of new studies associating cold and drought tolerance in coffee.