Coffee Science - v.14, n.4, 2019
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/12725
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Item Quizalofop-P-ethyl controlling sourgrass (Digitaria insularis) and goosegrass (Eleusine indica) in infested coffee areas(Editora UFLA, 2019-10) Vilela, Ximena Maira de Souza; Medeiros, Fernanda Carvalho Lopes de; Gonçalves, Adenilson Henrique; Silva, Lindomar Canuto daChemical control is the main weed management system in coffee crop. Herbicides alternatives controlling grass weeds in infested coffee areas are limited, mainly due to the few options of registered herbicides. Thus, it is important to evaluate selective post-emergence herbicide to control these important weeds in coffee crop. The objective in this work was to evaluate the selectivity, efficiency and agronomic viability of the herbicide quizalofop-P-ethyl compared to GLI OVER SL (glyphosate) on grass control in coffee crop. Two experiments were carried out in randomized blocks with four replicates in the municipality of Lavras and Santana da Vargem (MG - Brazil) in a commercial coffee crop cultivar “Mundo Novo” and “Catuai” to evaluate the herbicide effectiveness in the crop rows. The experimental design was a randomized block design with seven treatments and four replicates. Treatments consisted of the herbicide doses (25, 50, 75 and 100 g a.i. ha-1) compared to the standard glyphosate at the dose of 1,680 g a.i. ha-1 + Iharol at 0.5% v/v. Application occurred when sourgrass and goosegrass were at the beginning of development with up to 4 tillers (early vegetative stage) and in a second trial, at advanced stages of development (highly branched and /or flowering). Control assessments in percentage were performed at 7, 14, 21 and 28 days after application (DAA) of the treatments. A note of phytotoxicity was given following the European Weed Research Council (EWRC) patterns. The control of weeds was evaluated in each experimental plot using the visual notes scale, where: 0% represents no control, and 100% total control of the species in question, compared to the population present in the non-weed control. In general, the dose of 1,500 and 2,000 mL per hectare of quizalofop-p-ethyl (75 and 100 g a.i. ha-1) for the weeds at early vegetative stage presented the highest levels of controls (above 90%). The dose of 2,000 mL per hectare (100 g a.i. ha-1) was efficient at 28 DAA to control more developed plants. No symptoms of phytotoxicity caused by the herbicide quizalofop-P-ethyl were detected at any dose tested. Quizalofop-P-ethyl can be recommended for integrated weed management in coffee for sourgrass and goosegrass.Item Selectivity of the herbicide chlorimuron ethyl on young coffee plants(Editora UFLA, 2019-10) Castanheira, Dalyse Toledo; Voltolini, Giovani Belutti; Alecrim, Ademilson de Oliveira; Rezende, Tiago Teruel; Menicucci Netto, Pedro; Silva, Larissa Cocato da; Guimarães, Rubens JoséThe great interference of weeds in coffee plants, due to competition for water, light and nutrients, makes their control essential. Among these control methods, the chemical stands out, due to its high efficiency and low cost. However, as a function of application failures, phytotoxicity is frequent in coffee plants due to herbicide drift. Aiming to search for active ingredients selective to coffee, the objective of this study was to evaluate the selectivity of the active ingredient Chlorimuron ethyl in coffee seedlings, and its effects on plant morphology, anatomy and physiology. The experiment was carried out in a greenhouse with ‘Topázio MG 1190’ coffee plants (Coffea arabica L.), grown in 11-L pots. The statistical design was in randomized blocks, with four replicates and four herbicide doses. Each plot consisted of three plants. The treatments were: 0%; 50%; 100% and 200% of the recommended commercial dose of the herbicide Chlorimuron ethyl. Evaluations were performed at 120 days after treatment application. Morphological, physiological and anatomical characteristics were evaluated, besides possible phytotoxicity symptoms inherent to herbicide application. The herbicide Chlorimuron ethyl caused phytotoxicity symptoms in coffee seedlings, evidenced from the leaflet dose, through leaf deformation and cracking, with growth losses not exceeding 10%, but without damage to plant physiology and anatomy.Item Phytotoxicity and growth of coffee plants as a function of the application of herbicide 2,4-D(Editora UFLA, 2019-10) Voltolini, Giovani Belutti; Castanheira, Dalyse Toledo; Silva, Larissa Cocato da; Alecrim, Ademilson de Oliveira; Rezende, Tiago Teruel; Barbosa, João Paulo Rodrigues Alves Delfino; Guimarães, Rubens JoséWeed control in coffee is of great importance for there is a great interference, standing out the competition for water, light and nutrients. Among the control methods, chemical control is highlighted as a function of its efficiency. However, the incorrect application of herbicides may imply the occurrence of drift, resulting in damage to coffee development due to phytotoxicity. In this context, the objective of this study was to evaluate the symptoms and phytotoxicity effects caused by the herbicide 2,4-D drift on the morphological, physiological and anatomical characteristics of coffee seedlings. The experiment was carried out in a greenhouse with ‘Topázio MG1190’ coffee seedlings (Coffea arabica L.), planted in 11-L pots. A randomized block design with four treatments and four replicates was used. The treatments were: 0%; 10%; 25% and 50% of the recommended commercial dose of 2,4-D (2.5 L.ha-1). Each plot consisted of three plants. The evaluations were performed at 74 days after implantation. Morphological, physiological, anatomical and phytotoxicity symptoms were evaluated as a function of the simulated herbicide drift. Coffee seedlings intoxicated by the herbicide 2,4-D presented hyponastic, chlorosis, shriveling and leaf anomalies. In the orthotropic branch, bending was observed in its extension, besides thickening in the collar region; in the plagiotropic branch, cracking was observed. Herbicide drift negatively affects the development of coffee plants. The coffee physiology was affected as a function of herbicide drift, but without damage to the leaf anatomy.