scholarly journals Efficiency of Isolated and Associated Herbicides to Control Glyphosate-Resistant Sourgrass

2019 ◽  
Vol 37 ◽  
Author(s):  
M. CASSOL ◽  
M.D. MATTIUZZI ◽  
A.J.P. ALBRECHT ◽  
L.P. ALBRECHT ◽  
L.C. BACCIN ◽  
...  

ABSTRACT: Sourgrass is one of the weeds of great economic importance in Brazil due to its difficulty of control and conditions that allow its emergence and development throughout the year. Thus, this study aimed to evaluate the effectiveness of clethodim and haloxyfop applied alone or mixed with glyphosate and other herbicides to control glyphosate-resistant sourgrass at different stages of development. For this, three experiments were conducted in the field: in experiment 1, the herbicides were applied in sourgrass plants with 6 to 8 tillers; and in experiments 2 and 3, when plants were at full flowering, with up to 18 tillers. After treatment application, visual evaluations were performed at 14, 21, 28, 35, 42, 49, and 56 days after application (DAA) in experiment 1 and at 7, 14, 21, 28, and 35 DAA in experiments 2 and 3. Also in experiment 3, the shoot of remaining plants was collected in the last control evaluation to measure the dry matter. In experiment 1, the treatment glyphosate + clethodim presented a satisfactory control close to 90%, but after 35 DAA, sourgrass plants started showing significant resprouts, decreasing the control. In experiments 2 and 3, treatments showed no control above 90% and the herbicides clethodim and haloxyfop had similar final control when in mixture with glyphosate. Therefore, the isolated herbicide application at the tested doses was not sufficient for efficient control of sourgrass at more advanced stages of development.

2020 ◽  
Vol 33 (3) ◽  
pp. 579-590
Author(s):  
RAFAEL ROMERO MENDES ◽  
HUDSON KAGUEYAMA TAKANO ◽  
DENIS FERNANDO BIFFE ◽  
JAMIL CONSTANTIN ◽  
RUBEM SILVÉRIO DE OLIVEIRA JUNIOR

ABSTRACT More than one herbicide application is usually necessary to manage glyphosate-resistant sourgrass in advanced stages of development efficiently during off-season fallow periods. The objective of this study was to determine the best interval between two sequential applications to control sourgrass, based on the number of days and tiller-height after the first treatment. Two experiments were conducted based on these criteria. Experiment 1 consisted of one application of glyphosate + clethodim (1140 ae ha-1 + 108 g ha-1) followed by glyphosate + clethodim or paraquat (400 g ai ha-1) at an interval of 10, 17, 24, 31, 28, or 45 days. Experiment 2 was conducted with the same herbicide treatments, but using the tiller-height as the criteria for the second application, which were 2-5, 6-10, 11-20, 21-30, and >30 cm. None of the treatments resulted in total sourgrass control during the evaluation period. Overall, treatments with glyphosate + clethodim in the second application were more efficient than paraquat. The most effective interval between sequential applications of glyphosate + clethodim was observed at 17 to 24 days. For paraquat, the best interval for the second application was 6-10 days. The most effective performances based on the tiller-height were found at 620 cm tall for glyphosate + clethodim and 6-10 cm tall for paraquat.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Luís Eduardo Panozzo ◽  
Dirceu Agostinetto ◽  
Pedro Valério Dutra de Moraes ◽  
Deivid Araújo Magano ◽  
Adilson Harter ◽  
...  

The species ofEchinochloa(barnyardgrass) stand out among major weeds infesting rice cropping and damages are variable depending on the weed population, rice cultivar, and management practices adopted by rice farmers. The objective of this work was to measure the control of barnyardgrass in rice cropping, cultivar Qualimax 1, due to the early times of flood irrigation, application times, and doses of penoxsulam. The experiment was conducted in the field, where the experimental design used a randomized block design with a split plot design with four replications. The treatments consisted of two application periods (early and late) of penoxsulam three times of irrigation start (1, 15 and 30 days after treatment application—(DAT)) and herbicide doses (0, 24, 36, 48 and 60 g ha−1). The herbicide penoxsulam revealed that combined with irrigation starting 15 days after herbicide application promoted efficient control of barnyardgrass.


2020 ◽  
Vol 1 (1) ◽  
pp. 77
Author(s):  
Scheila Lúcia Ecker ◽  
Adriana Lugaresi ◽  
Gian Carlos Girardi ◽  
Bachelor Louis ◽  
Leandro Galon ◽  
...  

The fig tree is rustic and one of the fruit species with great economic importance, because it adapts easily to different climate and soil types. The objective of this study was to evaluate the influence the branches number and the fig tree cultivar on yield and fruit quality. The orchard implanted with two cultivars, Roxo de Valinhos and Pingo de Mel, and conducted with different numbers of productive branches, being: 16, 24 and 32. The utilized lineation was completely randomized, with three replicates, each replicate being composed of four plants. The analyzed variables were: branches length (cm), number of fruits per plant, number of fruits per branch meter, yield of mature fruits (Kg ha-1), yield of green fruits (Kg ha-1), accumulated productivity (Kg ha-1), fruit size (cm3), average fruit weight (g), soluble solids (°Brix) and fruit dry matter (%). The daily elongation rate and the mean length of the branches did not influence the different treatments. For productivity, noticed superiority on cultivar Roxo de Valinhos, with the higher the number of productive branches in the plants. Fruit quality, relative to soluble solids and dry matter, also did not influence the treatments. Fruits in larger caliber and size found from plants of the cultivar Roxo de Valinhos. Both for the production of fruits for fresh consumption and for the industrialization it is recommended the conduction with greater number of productive branches being between 24 and 32, for the greater productive yield.


2020 ◽  
Vol 110 (11-12) ◽  
pp. 838-843
Author(s):  
Philipp Müller ◽  
Bernd-Arno Behrens ◽  
Sven Hübner ◽  
Hendrik Vogt ◽  
Daniel Rosenbusch ◽  
...  

Techniken zur Steigerung der Formgebungsgrenzen in der Umformtechnik sind von hoher wirtschaftlicher Bedeutung. In dieser Arbeit wird eine Schwingungsüberlagerung im Krafthauptfluss eines Axialformprozesses zur Ausprägung einer Verzahnungsgeometrie untersucht. Die Auswirkungen der Schwingung auf die erzielbare Ausfüllung der Zahnkavitäten werden analysiert sowie die Parameter Schmierung und Oberflächengüte der Halbzeuge in ihrer kombinierten Wirkung untersucht. Es konnte eine Reduzierung der mittleren Umformkraft sowie eine Erhöhung der Formfüllung festgestellt werden. Techniques for extending the production limits in forming technology are of great economic importance. In this research, a superimposed oscillation in the main force flow of an axial forming process to form an axial gear geometry is investigated. The effects of the superimposed oscillation on the achievable form-filling of the tooth cavities are analyzed and the parameters lubrication and surface quality of the semi-finished products are investigated in their combined effect. A reduction of the averaged forming force as well as an increase of the form-filling could be achieved.


Author(s):  
Marin ANDREI ◽  
Marinela Roxana ROŞESCU

The research of the synanthropic plant species characteristics from the urban environment offers information about their relation with the anthropic environment, on one hand, and on the other hand, they can be used as indicators of the pollution level. The research was performed in the city of Pitesti from June 2008 to may 2009, to compile an inventory of the flora, to establish the biological and ecological spectrum, the phytogeographic elements and their economic importance. The fresh above ground phytomass of the synanthropic species from 22 sample locations, was determined. The dry matter, the total nitrogen and phosphorus content, for six species of the dominant synanthropic plants, were also determined. It was identified 214 species of 38 families. The biological and ecological spectra show the high percentages of hemicryptophytes (35%), eutrophic species (54%), xeromesophilous-mesophilous species (29%) as well as eurytherm (20%) and euryacide species. The phytogeographic spectrum shows a high number of species from Eurasia (96 species). From the total number of identified species, 54% are polyploid and 27% present economic importance. It was found that the phytomass from stationaries varies between 281.7 g m-2 and 21.5 g m-2, for a number of 35 species. The highest dry matter content (64.01%) was recorded in Conyza canadensis, the highest value of N (8,200 ppm) in Lactuca serriola and the highest total P content (301.5 ppm) in Erigeron annuus. The results enable us to estimate the value of the synanthropic plants as ecologic indicators in the Pitesti area.


2021 ◽  
Vol 10 (11) ◽  
pp. e131101118963
Author(s):  
Esther Mirian Cardoso ◽  
Paulo Allison Costa da Mata ◽  
Matheus dos Santos Souza ◽  
Maria Clara Pinheiro de Souza ◽  
Victoria Isaac

The fishery of mapará (Hypophthalmus marginatus) is of great economic importance in the Amazon region. Despite this, it is observed that the current norms of management disagree with the ethnoknowledge of fishermen of the Tocantins river. Therefore, there are many seizures and fines in the Tocantins Low region. This work appeared as a demand of the fishermen of the region and had as purpose to test the pertinence of the fishing legislation on the capture of the species and to provide subsidies for the adaptation of the norms to the local reality. For this, a mapará fishery was taken on the Pindobal Grande river, in the municipality of Igarapé-Miri, in the state of Pará. A sample of the captured individuals was collected, and identification, sexing and biometry were done. Fishing was described, and the sex ratio tested with the Chi-Square test and the mean length differences between the sexes with the Student's t-test. The results were compared with current legislation and literature data. The captured mapará individuals were mostly above 30 cm, as determined by legislation. It is concluded that, despite using a network that is prohibited, the capture of the species in the region acts selectively, due to the ethno-cognition and the fisherman's action ("taleiro"). Therefore, it is necessary that the legislation be revised, seeking the reconciliation between the conservation of ecosystems, the traditional knowledge and the socioeconomic development of the region.


1959 ◽  
Vol 40 (4) ◽  
pp. 172-178
Author(s):  
R. E. Munn

The topic is approached from the viewpoint of community air-pollution programs and control. After a brief discussion of the economic costs of atmospheric pollution in an industrial area, a skeleton outline of the important factors in weathering by pollutants is presented. A few of the factors are considered in detail under the general headings of soiling, erosion, and corrosion. Significant differences in weathering are found for industrial, rural, marine, and very dry climates. Most community surveys include routine tests of the dirtiness of the air but exclude corrosion tests, although this factor is of great economic importance. Methods of corrosion testing are considered, and it is concluded that they are not feasible yet for community surveys. Increasing interest in corrosion, however, is undoubtedly leading to a broader understanding of the problem.


1992 ◽  
Vol 28 (4) ◽  
pp. 473-476 ◽  
Author(s):  
K. P. Prabhakaran Nair ◽  
V. Ngachie ◽  
F. Nzetchoung

SUMMARYGroundnut (Arachis hypogaea) has very great economic importance in Cameroon. In pot experiments, groundnut yields on highly acidified but limed soil were 50% greater than those on unlimed soil. These results demonstrate that severely acidified soils of the western highlands of Cameroon should be limed at moderate rates to sustain crop productivity.


1986 ◽  
Vol 37 (5) ◽  
pp. 459 ◽  
Author(s):  
GD Batten ◽  
IF Wardlaw ◽  
MJ Aston

Experiments were designed to examine the effect of the level and duration of application of phosphorus (P) on yield in wheat and the effect of growth conditions prior to anthesis on the utilisation of P taken up during the early stages of development. In the first experiment, wheat (Triticum aestivum cv. Kite) was grown in sand and supplied with a complete nutrient solution containing either 1 mM phosphate or 0.25 mM phosphate. The supply of P was maintained until grain maturity, or stopped at different stages of development (floral initiation, flag leaf emergence, anthesis). The increase in total plant dry matter over this period ranged from 8.8 to 17.6 g/plant, with the 1.0 mM P supply and from 4.1 to 9.5 g/plant with the 0.25 mM P supply. Supply of P beyond anthesis resulted in more tiller dry matter and increased the P content of the grain, but did not increase grain yield at either level. With 1 mM P to maturity, up to 21% P of the grain P could be attributed to retranslocation of P within the plant after anthesis. With 0.25 mM P to floral initiation, 58% of the grain P could be attributed to such retranslocation. In a second experiment plants (cv. Kite) were grown initially at 18/13�C with 0.25 mM P until floral initiation and thereafter with a P-free solution until maturity. Between floral initiation and anthesis plants were placed in six dayhight temperatures, extending (in 3�C steps) from 15/10�C to 30/25OC, and then returned to the standard condition of 18/13�C. Higher pre-anthesis temperatures reduced the pre-anthesis growth period and the plant height, but increased the leaf phosphorus concentration and uptake of phosphorus per plant in both the pre- and post-anthesis periods. Net CO2 exchange indicated that leaf senescence in P-deficient plants was closely associated with the export of nitrogen as well as the export of P. Grain P increased from 0.15% to 0.3% when the preanthesis temperature was increased from 15/10 to 30/25�C, although grain yield per main culm did not vary greatly. These findings highlight the importance of environmental conditions in determining the level of P deficiency in wheat, and show that grain yield is not limited by the amount of P in the grain.


1911 ◽  
Vol 8 (12) ◽  
pp. 539-549 ◽  
Author(s):  
James Park

With the question of conformity or unconformity between the Lower Tertiary and Upper Cretaceous, there is associated a problem of great economic importance to New Zealand. The subject involves something more than a mere academic discussion. If conformity exists, then we have only one coal-bearing formation; but if unconformity, then we have two. I believe that both the stratigraphical and palæontological evidence is overwhelmingly in favour of the latter.


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