Coffee Science_v.15, 2020
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/12726
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Item Phytotoxicity and leaf anatomy of young coffee plants subjected to herbicides exclusively and in associations(Editora UFLA, 2020) Rodrigues, Rafael Jorge Almeida; Gonçalves, Adenilson Henrique; Menicucci Netto, Pedro; Carneiro, Arthur Henrique Cruvinel; Castanheira, Dalyse Toledo; Guimarães, Rubens José; Carvalho, Gladyston RodriguesThe lack of work force and the damage that weeds can cause to coffee plants are the causes of the growing demand for selective herbicides to be used in coffee farming. Thus, the objective of this study was to evaluate the phytotoxicity symptoms and leaf anatomical characteristics of young coffee plants submitted to application isolated herbicides and also in associations. An experiment was carried out in a protected environment in randomized blocks: four replicates with coffee seedlings (Coffea arabica L.) cultivar “Topázio MG-1190”, grown in pots with a capacity of 11 liters of substrate. The herbicides applied, in isolation, were: pyrazosulfuron-ethyl (0.015 kg ha-1), saflufenacil (0.049 kg ha-1), imazetaphyr (0.1 kg ha-1), iodosulfuron-methyl (0.0035 kg ha-1), chlorimuron-ethyl (0.015 kg ha-1) and sethoxydim (0.184 kg ha-1). The latter was used in associations with the others. In addition, a control without herbicides was used. Phytotoxicity symptoms were evaluated up to 49 days after application (DAA) and anatomical characteristics at 65 DAA. Saflufenacil exclusively and inassociation with sethoxydim caused visual phytotoxicity symptoms in the leaves and negatively influence in the characteristics of the epidermis thickness of the adaxial face (EAD), thickness of the palisade parenchyma (PAP), thickness of the spongy parenchyma (SPP) and thickness of the mesophyll (MES). The other herbicides, isolated or in associations, didn’t cause phytotoxicity symptoms, but had negative influence in the anatomical parameters of the leaf blade. However they did not interfere with the paradermic parameters and the vascular bundle.Item Agronomic performance of coffee in response to framework pruning in cycles of the “safra zero”(Editora UFLA, 2020) Maia, Pedro Lage; Tassone, Guilherme Augusto Teixeira; Nadaleti, Denis Henrique Silva; Botelho, Cesar Elias; Botelho, Deila Magna dos Santos; Moreira, Priscila Carvalho; Carvalho, Gladyston RodriguesIn this paper, we aimed at selecting genotypes of Coffea arabica L. that are responsive to framework pruning, with high productive potential and desirable agricultural features. We evaluated 18 progenies in the F5 generation, 8 of them being from the group Catucaí (breeding of seedlings of Red Catuaí with coffee seeds of the Icatu germplasm) and ten descendants from the Timor Hybrid (breeding of the Red and Yellow Catuaí with the Timor Hybrid), as well as two commercial cultivars as control (Tupi IAC 1669-33 and Obatã IAC 1669-20). The experiment was carried out at the experimental field of the Federal University of Lavras. The coffee was pruned in August 2014 after the sixth crop and once again in August 2016, being two cycles in the “safra zero” system. The design used was in randomized blocks (RBD) with three repetitions and 20 treatments (18 progenies and two commercial cultivars) totaling 60 experimental plots. We evaluated the area under the progress curve of incidence and severity of leaf rust and cercosporiosis, the productivity (sacs ha-1), sieve #16 and over (%), mocha-type grains (%) and apparent specific mass of grains (tonm-3). The genotype 12 (H516-2-1-1-18-1-4) was responsive to the framework pruning and kept its productivity stable in both pruning cycles, being efficient in such system of crop conduction, besides presenting low incidence and severity of coffee leaf rust and cercosporiosis and high sieve.