Brazilian Archives of Biology and Technology
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/12090
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Item Influence of coffee pruning on the severity of frost damage(Instituto de Tecnologia do Paraná - Tecpar, 2000-03) Androcioli Filho, Armando; Caramori, Paulo HenriqueFrost damages in a field experiment of pruning types and systems for the cultivars of Coffea arabica Catuaí and Mundo Novo, were evaluated at Londrina (23 o 22’S, 52 o 10 ́W), State of Parana, southern Brazil, during the winter of 1990 and 1994. Pruning types evaluated were ‘esqueletamento’ (cutting off all plagiotropic branches at 20-30 cm from the orthotropic branch), ‘decote’ (cutting off the orthotropic branch at 1.5 m and 2.0 m above ground) and ‘recepa’ (cutting off the orthotropic branch at 0.8 m above ground), performed on all rows and on alternate rows, and on different sections of the plant. Results indicated that frost damage could increase according to the type and height of pruning. The pruning type ‘esqueletamento’ and prunings at higher levels were more suitable for regions with frost risk. Under severe frost condition, pruning type did not affect the damage in anyone of the treatments evaluated.Item 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 CarlosModifications 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.Item 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, JoãoYoung 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.