37 research outputs found
Control of Panicum maximum in sugar cane with preemergence herbicides
Avaliou-se a eficácia dos herbicidas imazapic, imazapyr e pendimethalin, aplicados em pré-ernergência na cultura da cana-de-açúcar, para controle de capim-colonião (Panicum maximum Jacq.).O trabalho foi realizado na Usina São Carlos, Jaboticabal-SP, em solo de classe textural argilosa. O delineamento experimental utilizado foi o de blocos ao acaso com quatro repetições. Os tratamentos foram: imazapic (73,5 e 98 g/ha), imazapyr (122 e 147 g/ha), imazapic+pendimethalin (50+ 1000 e 60+ 1200 g/ha) e pendimethalin (1200 g/ha), além das testemunhas capinada e sem capinas. Para aplicação dos herbicidas foi utilizado um pulverizador costal, à pressão constante (mantida por ar comprimido) de 2,8 kg/cm-, com bicos de jato plano ("leque") DG 11002 e consumo de calda equivalente a 250 l/ha. A variedade de cana-de-açúcar utilizada foi a RB 72454, 3°corte. Tanto o imazapic como o imazapyr proporcionaram resultados considerados muito pobres no controle de P maximum. A mistura de imazapic + pendimethalin apresentou excelente desempenho no controle desta espécie, podendo ser utilizada na menor dose testada. O pendimethalin isolado (1200 g/ha) foi levemente inferior às misturas, mas com resultados ainda considerados muito bons, podendo também ser recomendado para a cultura.The major problem with the sugar cane crop is weed competition, specially Panicum maximum Jacq., which is a very agressive plant. The trial was carried out at Usina São Carlos (a sugar will), in Jaboticabal-SP, during 1998/1999 aiming to study imazapyr and imazapic herbicides, sprayed alone in preemergence, or imazapic in mixture with pendimethalin, for P maximum control. The experimental design was a randomized block with nine treatments and four replications. The treatments were: controls (with and without weeds), imazapic (73.5 and 98 g/ha), imazapyr (122 and 147 g/ha): imazapic+pendimethalin (50+ 1000 and 60+ 1200 g/ha) and pendimethalin (1200 g/ha) at preemergence. The herbicides were applied with a manual sprayer, with constant pressure of 2.8 kg/crrf and jet nozzles with descontinuous deposition (DG11002), using 250 Ilha of the herbicide solution. The sugar-cane variety used was RB 72454. The best preemergence weed control was observed with imazapic+pendimethalim in ali treatments 126 days after application. The postemergence treatment cannot be used because they caused high crop toxicity. The herbicide mixture (imazapic+pendimethalin) showed low efficiency in ali tested treatments
Eficácia e seletividade do herbicida flumioxazin aplicado em pré-emergência na cultura transplantada da cebola
The work was carried out to evaluate the herbicide flumioxazin performance compared to commercial patterns applied in pre-emergency in the transplanted onion culture. Field trials were carried out in Monte Alto, SP, arranged in a randomized complete block design with four repetitions. The used herbicides were: flumioxazin (0,080; 0,120; 0,180; 0,240 kg ha-1), oxadiazon + linuron (0,500 + 0,900 kg ha-1), linuron (1,350 kg ha-1) and oxadiazon (0,75 kg ha-1). Two controls also were maintained, one with and other without weed control during all the culture cycle. The portions consisted of four spaced lines of 0,36 m and three meters in length each, totalling 4,32 m2 area. Were considering useful the three central lines. The distance among plants in the line was 0,36 m. All the herbicides were considered excellent for the Lepidium virginicum control, standing out flumioxazin (100%) in all the dosages, until the 80 days after application (DAA), with great selectivity for the culture. The plants recovered well of the initial symptoms of the oxadiazon (0,750 kg ha-1). The mixture oxadiazon + linuron (0,500 + 0,900 kg ha-1) as well as isolated linuron (1,350 kg ha-1), promoted fitotoxicity varying moderate to medium.O trabalho foi realizado com o objetivo de avaliar o desempenho do herbicida flumioxazin comparado aos padrões comerciais aplicados em pré-emergência na cultura transplantada da cebola. O experimento foi instalado em Monte Alto, SP, segundo o delineamento experimental de blocos ao acaso com quatro repetições. Os herbicidas utilizados foram: flumioxazin (0,080; 0,120; 0,180; 0,240 kg ha-1), oxadiazon + linuron (0,500 + 0,900 kg ha-1), linuron (1,350 kg ha-1) e oxadiazon (0,75 kg ha-1). Também foram mantidas duas testemunhas, uma com e outra sem controle das plantas daninhas durante todo o ciclo da cultura. As parcelas constaram de quatro linhas espaçadas de 0,36 m e três metros de comprimento cada, totalizando área de 4,32 m2. Foram consideradas úteis as três linhas centrais. A distância entre plantas na linha foi de 0,36 m. Todos os herbicidas foram considerados excelentes para o controle de mentruz (Lepidium virginicum.), destacando-se flumioxazin (100%) em todas as dosagens, até os 80 dias após a aplicação (DAA), com grande seletividade para a cultura. As plantas recuperaram-se bem dos sintomas iniciais do oxadiazon (a 0,750 kg ha-1). A mistura de oxadiazon + linuron (0,500 + 0,900 kg ha-1), assim como, o linuron isolado a 1,350 kg ha-1, promoveram fitointoxicação variando de moderada a média
Eficácia do flumioxazin, aplicado isolado e em mistura com Glyphosate, para o controle de plantas daninhas em citros
It was evaluate the efficacy of the herbicide flumioxazin, applied isolated and in mixture with glyphosate, in orange orchard, for control of Panicum maximum, Cenchrus echinatus, Digitaria horizontalis, Alternanthera tenella, Bidens pilosa, Malvastrum coromandelianum, Commelina benghalensis, Amaranthus spinosus and Ageratum conyzoides. The treatments were: 0.025 and 0.05 kg ha-1 of flumioxazin (plus mineral oil 0.5%); 0.025 kg ha-1 of flumioxazin plus 1,08 kg e.a. ha-1 of glyphosate (plus mineral oil 0.5%); 0.025 kg ha-1 of flumioxazin plus 1.44 kg e.a. ha-1 of glyphosate (plus mineral oil 0.5%); 1.08 and 1.44 kg e.a. ha-1 of glyphosate. It was kept two checks: weeded and hand hoed. The herbicides were applied using costal sprayer, constant pressure (30 lbf pol-2), with four nozzles Teejet XR 110.02. The equivalent spray volume was 200 L ha-1 . The weed control evaluations were realized 7, 13, 29, 50, 70 and 133 days after herbicide application, in percentages. It was also evaluated herbicide fitotoxicity toculture. The mixture of flumioxazin with glyphosate, as well as isolated glyphosate, resulted in excellent weed control, in all dosages tested. Not were observed intoxication in citrus plants.Avaliou-se a eficácia do herbicida flumioxazin, aplicado isolado e em mistura com o glyphosate, na cultura de laranja, para controle de Panicum maximum, Cenchrus echinatus, Digitaria horinzotalis, Alternanthera tenella, Bidens pilosa, Malvastrum coromandelianum, Commelina benghalensis, Amaranthus spinosus e Ageratum conyzoides. Os oito tratamentos testados foram: 0,025 e 0,05 kg ha-1 de flumioxazin (mais óleo mineral a 0,5%); 0,025 kg ha-1 de flumioxazin mais 1,08 kg e.a. ha-1 de glyphosate (mais óleo mineral a 0,5%); 0,025 kg ha-1 de flumioxazin mais 1,44 kg e.a. ha-1 de glyphosate (mais óleo mineral a 0,5%); 1,08 e 1,44 kg e.a. ha-1 de glyphosate, além das testemunhas capinada e infestada. Os herbicidas foram aplicados utilizando-se pulverizador costal manual, à pressão constante (30 lbf pol-2), munido de barra com quatro bicos tipo “leque” XR 110.02 e consumo de calda equivalente a 200 L ha-1. As avaliações visuais de controle foram realizadas aos 7, 13, 29, 50, 70 e 133 dias após a aplicação, atribuindo-se notas em percentagens. A fitotoxicidade dos herbicidas às plantas cultivadas também foi avaliada. A mistura de flumioxazin com glyphosate, assim como glyphosate isolado, resultou em excelente controle das plantas daninhas, em todas as doses testadas, com exceção de C. benghalensis. Não houve benefício da mistura dos herbicidas, nem para C. benghalensis que não é bem controlada pelo glyphosate. Os herbicidas não causaram intoxicação às plantas de citros
Influência do momento da chuva na eficácia do herbicida glifosate, em diferentes concentrações, no inverno e no verão
Two field assays were carried out aiming to evaluate the rain effects on the glyphosate herbicide activity, applied at different concentrations, under two growing seasons (winter and summer). The experiments were conducted at the FCAV / UNESP Experimental Station, during 2000/01. The winter experiment was installed from June to August of 2000 and the summer one was installed from January to March of 2001. The treatments were glyphosate (0,5; 1,0; 2,0 e 4,0%), used as check treatment. In the field, all the trials were set up in the randomized block experimental design, with four replications. The experimental plots was 3.0 m wide x 3.5 m long in the winter assays. In the summer one, the plots' size was 3.0 m x 4.0 m. The treatments were arranged in factorial designs 5 x 4 factors, with five periods between the herbicide spraying and the rain incidence and four concentrations. The herbicide treatments were applied through a back spraying, with six nozzles DG 11002 spaced by 0.5 m, at 30 p.s.i. constant pressions. The artificial rain was provided by a top irrigation system raining 18 - 19 mm during one hour. The artificial rain reduced the glyphosate action, mainly in the shorter periods. Raising the glyphosate concentration to 2.0% supressed the problems promoted by the rain, one hour after sprayings, under winter conditions. Similar results were observed raising the glyphosate concentration to 1.0%, under summer conditions.Com o objetivo de estudar a influência da chuva sobre a eficácia de diferentes concentrações do herbicida glifosate em duas épocas do ano foram instalados dois experimentos. O de inverno foi realizado no período de julho a agosto de 2000 e o de verão, de janeiro a março de 2001. Utilizou-se o delineamento experimental de blocos ao acaso, com quatro repetições, com os tratamentos dispostos em esquema fatorial (4 X 5) + 1, sendo constituído por quatro concentrações de glifosate SAqC (360 g.L-1 de eq. ac.) (0,5; 1,0; 2,0 e 4,0%) na calda de pulverização, correspondendo as doses crescentes de 360, 720, 1440 e 2880 g.ha de eq.ac., cinco intervalos sem chuva após a aplicação. (1, 2, 4, 6 e > 48 horas) e uma testemunha sem herbicida. A unidade experimental foi constituída por uma parcela 3,0 X 3,5 no inverno e 3,0 X 4,0 metros no verão. Os tratamentos foram aplicados em pós-emergência das plantas daninhas, utilizando-se um pulverizador costal, à pressão constante (mantida por ar comprimido) de 30 lbf/pol2, munido de barra com seis bicos DG 11002, espaçados de 0,5 m. Tanto no inverno como no verão foi simulada uma chuva de aproximadamente 20 mm em 60 minutos com o auxílio de um sistema de irrigação por aspersão. Nas duas épocas, a ocorrência da chuva foi prejudicial à ação do glifosate, principalmente nos menores intervalos sem chuva após a aplicação. Para proporcionar controle semelhante ao tratamento com intervalo de 48 horas sem chuva após a aplicação, no inverno, a concentração do herbicida na calda de 2,0% v/v (1440 g. ha-1 de eq. ac. De glifosate) exigiu intervalo de pelo menos duas horas sem chuva após a aplicação. No verão, para alcançar o mesmo nível de controle foi necessário um período de pelo menos uma hora sem chuva após a aplicação, para a mesma dose de glifosate, e com a concentração do herbicida na calda de 1% v/v (720 g. ha-1 de eq. ac. de glifosate) obteve-se resultado satisfatório com período superior a duas horas sem chuva após a aplicação
Recommended from our members
BioTIME: A database of biodiversity time series for the Anthropocene.
MotivationThe BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.Main types of variables includedThe database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record.Spatial location and grainBioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km2 (158 cm2) to 100 km2 (1,000,000,000,000 cm2).Time period and grainBioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year.Major taxa and level of measurementBioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.Software format.csv and .SQL
Recommended from our members
A social and ecological assessment of tropical land uses at multiple scales: the Sustainable Amazon Network
Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazonia Sustentavel, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far.Keywords: Social–ecological systems, Tropical forests, Land use, Interdisciplinary research, Sustainability, Trade-off
Recommended from our members
Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests
The seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combination of seasonal pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measurements and 35 litter productivity measurements), their associated canopy photosynthetic capacity (enhanced vegetation index, EVI) and climate, we ask how carbon assimilation and aboveground allocation are related to climate seasonality in tropical forests and how they interact in the seasonal carbon cycle. We found that canopy photosynthetic capacity seasonality responds positively to precipitation when rainfall is < 2000 mm yr⁻¹ (water-limited forests) and to radiation otherwise (light-limited forests). On the other hand, independent of climate limitations, wood productivity and litterfall are driven by seasonal variation in precipitation and evapotranspiration, respectively. Consequently, light-limited forests present an asynchronism between canopy photosynthetic capacity and wood productivity. First-order control by precipitation likely indicates a decrease in tropical forest productivity in a drier climate in water-limited forest, and in current light-limited forest with future rainfall < 2000 mm yr⁻¹
Doses reduzidas de fluazifop-p-butil + fomesafen no controle de plantas daninhas na cultura de soja
Com o objetivo de avaliar o efeito de doses reduzidas da mistura formulada de fluazifop-p-butil + fomesafen, aplicado em condições de pós-emergência, no controle de plantas daninhas e na produtividade de dois cultivares de soja, foi instalado um experimento no município de Jaboticabal-SP, ano agrícola de 2000/01. Utilizou-se delineamento experimental em blocos ao acaso, no esquema de parcelas subdivididas, com quatro repetições. Os cultivares IAC - Foscarin 31 e MG/BR46-Conquista constituíram as parcelas, e as doses do herbicida fluazifop-p-butil + fomesafen (0,4; 0,3; e 0,2 kg i.a. ha-1), juntamente com as testemunhas (com e sem capinas), as subparcelas. Constatou-se maior fitointoxicação do herbicida no cultivar IAC - Foscarin 31, sem, no entanto, afetar a produção de grãos. Foi possível a redução de até 50% na dose do herbicida, para o controle da comunidade infestante estudada, com produções estatisticamente iguais ao manejo por capinas durante todo o ciclo.This experiment was carried out in Jaboticabal, São Paulo - Brazil, during the 2000/01 growing season, to test the effect of reduced doses of formulated mixture of fluazifop-p-butil + fomesafen, in postemergence application, on weed control and yield of two soybean cultivars. A randomized block experimental design was used with four replications, in a split-plot design. The cultivars (IAC - Foscarin 31 and MG/BR46-Conquista) constituted the plots and the fluazifop-p-butil + fomesafen herbicide rates (0,4; 0,3; and 0,2 kg. a.i.ha-1), together with the checks (with and without weed), the split-plots. A major phytotoxicity of the herbicide was verified for the IAC - Foscarin 31 cultivar, but without affecting yield. It was possible to reduce the herbicide rates up to 50% to control this weed community, without significant yield reduction.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP