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URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
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Item Evaluation of leaf and root absorptions of glyphosate in the growth of coffee plants(Instituto Biológico, 2020) Barbosa, Edimilson Alves; Silva, Isabel Moreira da; França, André Cabral; Silva, Enilson de Barros; Matos, Christiano da Conceição deIntoxication by dispersion of glyphosate droplets in coffee seedlings is common and, in addition to the problem of drift, there are reports of contamination of this herbicide to a nontarget plant via the rhizosphere. Hydroponics allows the comparison of the translocation of the glyphosate absorbed by the foliage or the roots and avoids the interaction with the soil, which could hamper the achievement of more accurate conclusions when it is absorbed by the root. Thus, the toxicity of glyphosate sublethal dosages in the initial growth of coffee plants in hydroponics was evaluated by applying four sublethal dosages in two different locations (solution and leaf). Fifty days after the application of the herbicide, the intoxication percentage and the growth of the coffee seedlings were evaluated. From the reduced dose of 115.2 g·ha-1 of glyphosate, height reductions, root length; number of leaves, dry mass of leaf, roots and total, leaf area, and leaf mass ratio were observed. The first two parameters were observed only in leaf application and the others via leaf and solution. The aerial part–root ratio system had an increase in herbicide sublethal dosages when applied to leaves and the ratio of leaf area and specific leaf area increased in both applications. Sublethal dosages of glyphosate applied to young coffee plants under hydroponic conditions impair their growth, and it is more accentuated with increasing doses and when the leaves, instead of the roots, absorb the herbicide.Item Mycorrhizal fungi increase coffee plants competitiveness against Bidens pilosa interference(Escola de Agronomia - UFG, 2016) França, André Cabral; Freitas, Ana Flávia de; Santos, Edson Aparecido dos; Grazziotti, Paulo Henrique; Andrade Júnior, Valter Carvalho deAs micorrizas proporcionam diversos benefícios às plantas de cafeeiro. Avaliou-se se esses benefícios influenciam nos danos causados pela competição de Bidens pilosa com plantas jovens de café. Utilizou-se delineamento em blocos casualizados, com tratamentos estabelecidos pelo fatorial 2 x 3 (presença e ausência da interferência de B. pilosa em plantas inoculadas com Claroideoglomus etunicatum ou Dentiscutata heterogama e não inoculadas). Plântulas de café foram inoculadas com esporos dos fungos e se desenvolveram por 120 dias. Em seguida, foram submetidas à interferência de B. pilosa por mais 120 dias, quando foram coletados dados de crescimento, colonização micorrízica, massa seca e teores foliares de nutrientes no cafeeiro. Também foram avaliados a massa seca e os teores de nutrientes em plantas de B. pilosa. A inoculação proporcionou melhor crescimento e nutrição das plantas de café. A competição com B. pilosa reduziu a colonização micorrízica, altura, área foliar, massa seca de folhas e de caule, massa seca de raízes, número de ramos plagiotrópicos e teores de P e Fe das plantas de café, porém, esse efeito foi menor nas plantas inoculadas. A massa seca de B. pilosa diminuiu sob a interferência de plantas de café inoculadas. A inoculação de C. etunicatum e D. heterogama, em mudas de café arábica, aumenta a capacidade competitiva da cultura frente à interferência de B. pilosa.Item Photosynthetic activity of coffee after application of glyphosate subdoses(Editora da Universidade Estadual de Maringá - EDUEM, 2013-01) Carvalho, Felipe Paolinelli de; França, André Cabral; Lemos, Vinícius Teixeira; Ferreira, Evander Alves; Santos, José Barbosa dos; Silva, Antonio Alberto daFarmers use non-selective herbicides, such as glyphosate, in directed applications to control weeds in coffee crops. Despite the precautions used during the application of herbicides, there are usually reports of poisoning in plantation areas. Moreover, it is fundamental to understand the effects of glyphosate on photosynthetic processes. The present study aimed to evaluate the characteristics associated with the photosynthetic activity in coffee cultivars subjected to doses of glyphosate. The experiment was conducted in a greenhouse using three varieties of coffee (Coffea arabica), including Acaiá (MG-6851), Catucaí Amarelo (2 SL) and Topázio (MG-1190), and three subdoses of glyphosate (0.0, 115.2 and 460.8 g ha -1 ) in a 3 x 3 factorial scheme. Herbicide application led to reduced internal carbon, ratio between internal and environmental carbon, carbon consumption and photosynthetic rate at 15 days after application (DAA) in the fourth leaf. In the same leaf at 45 DAA, the carbon consumption of the cultivars was even less. Despite low carbon concentrations, no difference in consumption and photosynthetic rate was observed in the last leaf. Glyphosate caused metabolic damage with transitory effects on the photosynthetic rate; the Acaiá cultivar was the most tolerant. These transitory effects may result in irreversible and prolonged damage to crop growth.