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| GAZZIERO,D.L.P.; ADEGAS,F.S.; SILVA,A.F.; CONCENÇO,G.. |
| ABSTRACT: Efficient management of sourgrass is one of the main challenges faced by Brazilian soybean farmers. Biological and ecological characteristics of this weed, as well as wide distribution of glyphosate-resistant biotypes, make it difficult to control this species. The objective of this work was to estimate interference of sourgrass in soybean yield. Seven experiments were conducted during three consecutive years (2012/2013, 2013/2014 and 2015/2016 cropping seasons); six of them were on-farm trials where sourgrass infestation was mainly originated from clump regrowth, while infestation originated from seeds in one trial. Data from all sites and experiments were submitted to a combined analysis, according to the study factors and variables, to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Digitaria insularis; Perennial; Glyphosate-resistant weed; Glycine max. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100246 |
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| FRANDOLOSO,F.S.; GALON,L.; CONCENÇO,G.; ROSSETTO,E.R.O.; BIANCHESSI,F.; SANTIN,C.O.; FORTE,C.T.. |
| ABSTRACT: The objective of this work was to evaluate the interference and to determine the level of economic damage (NDE) of the weed when infesting the corn crop. Treatments were composed by corn densities (2.60, 3.10, 3.65, 4.00 and 4.80 plants m-1) and 10 Alexandergrass populations for each crop seeding density. The population of plants, leaf area, soil cover and shoot dry mass of Alexandergrass were evaluated as indicator of infestation. Shoot dry mass of Alexandergrass presents better adjustment to the model of rectangular hyperbole, and losses of grain yield due to interference of the weed were satisfactorily estimated by this model. Corn sowing densities of 2.60; 3.10 and 3.65 plants m-1 in average, were more competitive of all evaluated variables... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Urochloa plantaginea; Zea mays; Competitive ability. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582020000100246 |
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| SILVA,M.S.A.; YAMASHITA,O.M.; ROSSI,A.A.B.; CONCENÇO,G.; CARVALHO,M.A.C.; FELITO,R.A.. |
| ABSTRACT: The monitoring of phytochemicals with potentially toxic properties can be assessed by observing the physiological and cellular alterations of the test organism exposed. This present study aimed to evaluate the cytotoxic and genotoxic potential of aqueous extracts of leaves and roots of Macroptilium lathyroides weed on the cell cycle of lettuce. Bioassays were conducted in a germinator (25 oC) with aqueous extract at concentrations of 0, 5, 10, 20 and 40% p v-1, obtained from fresh leaves and roots. For biological, lettuce root meristems were used for the preparation of slides using the technique of squashing. All blades were observed with an optical microscope at a magnitude of 400x. A total of 5,000 cells were analyzed for each treatment, and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Abnormalities; Bioassays; Cell division; Phasey bean; Mitotic index. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100244 |
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| CONCENÇO,G.; ANDRES,A.; SCHREIBER,F.; SILVA,A.F.; MOISINHO,I.S.; CORADINI,M.C.. |
| ABSTRACT: The aim of this study was to evaluate the occurrence of weeds in flooded rice areas, as a function of planting system and herbicide programmes in the previous cropping year. The experiment was installed in field conditions, in randomized complete blocks design, arranged in factorial scheme 3 x 2, with eight replications. In factor A, treatments consisted on conventional tillage, minimum tillage and no till cropping systems, coupled to the application (traditional control) or not (semi-ecological system) of herbicides (Factor B). One year after rice cultivation, preceding the planting of the next cropping season, phytosociological evaluations of the weed communities present in the treatments were carried out. We assessed the overall infestation... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chemical control; Semi-ecological rice; Phytosociology; Southern Brazil. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100286 |
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| MACHADO,L.A.Z.; COMUNELLO,É.; CECATO,U.; CONCENÇO,G.. |
| ABSTRACT: The purpose of this study was to evaluate forage plant susceptibility in Urochloa ssp. and Megathyrsus maximus with two glyphosate herbicide doses, to increase the efficiency of integrated crop-livestock farming systems. A randomized block design was adopted, in a split-plot arrangement, with six replications. In the main plots, the following treatments were established: Urochloa ruziziensis, U. decumbens, U. brizantha cvs. Xaraés, BRS Piatã and BRS Paiaguás, Megathyrsus maximus cvs. Aruana and BRS Tamani; in the subplots, there were doses of glyphosate herbicide; 0.72 and 1.44 kg a.e. ha-1. The estimated control percentage was consisted of a grading scale from zero (fully living tiller) to 100 (fully dead tillers), assigned 7; 14; 21 and 28 days... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Brachiaria; Desiccation; Megathyrsus; Panicum; Urochloa. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582018000100302 |
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| CONCENÇO,G.; CONCENÇO,S.E.. |
| Conyza spp. are widely responsible for yield losses in agriculture due to its worldwide occurrence, resistance to herbicides and other traits which turn these species into first grade weeds. Since the 1980's, these species started to be cited on books both related to the ecology and the weed science, being usually classified as ruderals. Occurrence of Conyza in crops shows that these species are highly adaptable due to its recent evolutionary origin and occur in environments prone concomitantly to a moderate set of competition, disturbance and stress. There are also limitations in Grime's theory which may lead us to mistakes about the behavior of Conyza. Thus, simple and isolated recommendations certainly will not solve the problem of Conyza. Neither soil... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Horseweed; Fleabane; Ruderal; Grime's theory; Demographic theory. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582016000100183 |
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