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URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
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Item Occurrence of arbuscular mycorrhizal fungi in leaf litter and roots of shaded coffee plantations under organic and conventional management(Sociedade Brasileira de Ciência do Solo, 2021) Díaz-Ariza, Lucía Ana; Rivera, Emma Lucía; Sánchez, NataliaEvidence of arbuscular mycorrhizal fungal colonization of mat litter in various ecosystems plus previous reports of external mycelium of those fungi and mycorrhizal roots in litter from coffee plants and shade trees on coffee plantations suggest that they have a relationship with closed direct nutrient cycling between organic matter and living roots. This relationship was first proposed more than 50 years ago. Mycorrhizal symbiosis in tropical crops is affected by agricultural management practices. This study aimed to assess the occurrence of arbuscular mycorrhizal fungi in leaf litter from three shaded Colombian coffee agroecosystems under organic and conventional management. One is managed chemically, one organically, and one with a combined use of organic and chemical inputs. Leaf litter and roots were collected from the three coffee plots at three decomposition stages. Each plot represented a distinct fertilization and tree dominance pattern different from the other two plots. Arbuscular mycorrhizal fungi were found in decomposing leaves. The chemically managed plot showed statistical differences (p<0.05) with respect to the other plots, it had the greatest amounts of arbuscular mycorrhizal fungal root colonization (48.76–70.51 %), litter colonization (36.2–69.91 %), external mycelium length (28.66–48.33 m g-1), and spore number (451.27–681.2 spores in 20 g of dry soil). In contrast, conditions on the combined management coffee plot results in smaller means of the variables evaluated. Arbuscular mycorrhizal fungal root colonization and nitrogen content of leaf litter varied among the decomposition stages (p<0.05). Litter quality of different tree species may have influenced colonization of plant matter within each plot. We found evidence of typical structures of arbuscular mycorrhizal fungi within and among decomposing leaf litter and roots growing into the mat litter in tropical agroecosystems. This supports the thought that these fungi have a role in carbon and nutrient recycling, which are influenced by agricultural management practices and plant population composition.Item Evaluation of Conilon coffee productivity intercropped with Ambarella (Spondias dulcis Parkinson)(Editora UFLA, 2020) Sales, Eduardo Ferreira; Baldi, Adriana; Alvez, Juan P.The State of Espirito Santo (Brazil) has 9.4 % of its area cultivated in full sun, monocrop coffee. Coffee has a great importance for the State and a dependence on just one product can make farmers vulnerable to price fluctuations. Integrating coffee (Coffea canephora Pierre ex Froehner) intercropped with Ambarella (Spondias dulcis Parkinson) offers environmental benefits and an extra financial combination through the commercialization of Ambarella fruits. The goal of this study was to verify the effects of the distance and orientation (East-West versus North-South) between Ambarella on coffee crop yield. We assessed two different coffee crops spaced (3 x 1.5) m. Both were intercropped with Ambarella spaced (15 x 7.5) m. The average coffee productivity varied from (2,177 to 7,346) kg plant-1. The lowest productivity was measured in the North-South orientation, during 2016, and the highest in the East-West orientation during 2017. Our findings also indicate that regardless of planting distance, Ambarella did not significantly affected coffee productivity demonstrating that it can be a promising fruit tree to intercrop with Conilon coffee.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.