Evaluation of tank mixtures of imazethapyr with other herbicides for Bidens pilosa and Euphorbia heterophylla control in soybean

Esse estudo teve por objetivo avaliar a seletividade para soja e eficiência de misturas em tanque de imazethapyr com outros latifolicidas. Os tratamentos avaliados foram imazethapyr (100 g/ha), imazethapyr + chlorimuron-ethyl (50+ 1O, 50+ 12,5 e 60+ 10 g/ha), jmazethapyr + lactofen (50+96, 50+120, 60+96, 60+120 e 12,5+120 g/ha), imazethapyr + oxasulfuron (50+37,5 e 60+37,5 g/ha), além de chlorimuron-ethyl + lactofen (12,5+120 g/ha), oxasulfuron (45 g/ha), chlorimuron-ethyl (15 g/ha), lactofen (168 glha), e testemunhas capinada e sem capina. Todos os herbicidas foram aplicados em pós-emergência, quando a soja encontrava-se no estádio V4 a V5 (3 a 4 folhas trifolioladas). As plantas daninhas presentes, densidades e estádios de desenvolvimento na área experimental eram Bidens pilosa (179 plantas/m', 2 a 4 folhas) e Euphorbia heterophylla (63 plantas/m-, 4 a 5 folhas). As misturas de imazethapyr com chlorimuron-ethyl, lactofen e oxasulfuron foram excelentes no controle de ambas espécies, não evidenciando diferenças significativas entre as diferentes misturas ou entre doses de uma mesma mistura. Em relação á E. heterophylla, as misturas contendo imazethapyr foram superiores a chlorimuron-ethyl +1 actofen, e ás aplicações isoladas de chlorimuron-ethyl e lactofen. As misturas com imazethapyr apresentaram um efeito residual até 21 dias após a aplicação para E. heterophylla. Nenhum tratamento com herbicidas afetou o desenvolvimento ou -produtividade da soja.This study was intended to evaluate the selectivity to soybean and efficiency to control Bidens pilosa and Euphorbia heterophylla of tank mixtures of imazethapyr and other broadleaf herbicides. Treatrnents included imazethapyr (100 g/ha), imazethapyr + chlorimuron-ethyl (50+ 10,50+ 12.5 and 60+ 10 g/ha), imazethapyr + lactofen (50+96,50+ 120,60+96,60+ 120 and 12.5+120 g/ha), imazethapyr+oxasulfuron (50+37.5 and 60+37.5 g/ha), chlorimuron-ethyl + lactofen (12.5+120 g/ha), oxasulfuron (45 g/ha), chlorimuron-ethyl (15 g/ha), lactofen (168 g/ha), and weedy and weed free checks. All combinations ofherbicides were applied postemergence, at V4-V5 soybean growth stage (3 to 4 composite leaves). Weeds, development stage and population density in experimental area were: Bidens pilosa (2 to 4 leaves and 179 plants/m") and Euphorbia heterophylla (4 to 5 leaves and 63 plants/m-). Tank mixtures of imazethapyr with chlorimuron-ethyl, lactofen and oxasulfuron were bighly eificient for both weeds, providing >97% control at pre-harvest evaluation, with no significant diferences among different mixtures or among different rates within each mixture. ln relation to E. heterophylla, mixtures containing imazethapyr were more eff1cient than both chlorimuron-ethyl+lactofen, and isolated use of chlorimuron-ethyl or lactofen. Mixtures containing imazethapyr provided a residual effect up to 21 days afier application for E. heterophylla. No chemical treatrnent affected soybean development or productivity.

No-tilIage management systems and their influence under postemergence herbicides in a soybean crop

O objetivo do trabalho foi avaliar diferentes sistemas de manejo em plantio direto e o controle em pós-emergência de plantas daninhas na cultura da soja, no município de São João do Ivaí (PR), no ano agrícola de 1998/99. Os tratamentos utilizados nos sistemas seqüenciais de manejo, para o controle de Commelina benghalensis (2 folhas até plantas ramificadas) e Brachiaria plantaginea (2 folhas até plantas perfilhadas), foram: (M I) sulfosate e paraquatldiuron+diquat (864 e 300+240 g/ha); (M2) sulfosate+2,4-D e paraquat/diuron+diquat (864+670 e 300+240 g/ha); (M3) sulfosate e paraquatldiuron+diquat (672 e 300+240 g/ha); (M4) sulfosate+2,4-D e paraquatldiuron+diquat (672+670 e 300+240 g/ha); (M5) testemunha sem aplicação. A primeira aplicação da seqüencial nos tratamentos MI e M2 realizou-se aos 26 dias antes da semeadura (DAS), e aos 40 DAS para M3 e M4, e a segunda aplicação no dia da semeadura para todos os tratamentos. Todos os sistemas de manejo foram subdivididos para avaliação do controle de C. benghalensis (I a 2 folhas) e R. raphanistrum (I a 2 folhas) após a emergência da soja, para os tratamentos com fomesafen (125 g/ha) em dose única 19 dias depois da semeadura (DDS), fomesafen e fomesafen (125 e 125 g/ha) em seqüencial aos 19 e 27 DDS, chlorimuron-ethyl+imazethapyr (10+ 150 g/ha) em dose única 25 DDS e testemunha sem aplicação. A antecipação do manejo, 40 DAS, possibilitou redução no uso de herbicidas e melhor controle de C. benghalensis e B. plantaginea, sendo que, onde o sistema de manejo obteve controle acima de 97% (M I e M4), a meia dose de fomesafen (125 g/ha) proporcionou controle satisfatório de C. benghalensis. A seqüência de sulfosate e paraquatldiuron+diquat possibilitou o manejo de C. benghalensis.The objective of the experiment was analyse different no-tillage management systems and postemergence control under a soybean crop, in São João do Ivaí (PR), in the agricultural year 1998/99. The treatments used in the management system sequence to control Commelina benghalensis (from 2 leaves to ramified plants) and Brachiaria plantaginea (from 2 leaves to tillered plants) were: (M1) sulfosate and paraquatldiuron+diquat (864 and 300+240 g/ha); (M2) sulfosate+2,4-D and paraquatldiuron+diquat (864+670 e 300+240 g/ha); (M3) sulfosate and paraquat/diuron+diquat (672 e 300+240 g/ha); (M4) sulfosate+2,4-D and paraquat/diuron+diquat (672+670 and 300+240 g/ha); (M5) control. The first application of the M1 and M2 sequence was carried out 26 days before sowing (DBS) and at 40 DBS with M3 and M4, and the second application was carried out on the sowing day for ali treataments. Ali manegement systems were subdivided and the control of C. benghalensis (I - 2 leaves) and Raphanus raphanistrum (I - 2 leaves) after soybean emergence was evaluated for the treatments with fomesafen (125 g/ha) in a single dose, 19 days after sowing (DAS); fomesafen and fomesafen (125 and 125 g/ha) in sequence 19 and 27 DAS; chlorimuron-ethyl+imazethapyr (10+ 150 g/ha) in a single dose 25 DAS, and a control. The antecipation ofthe management (40 DAS), facilited reduction in herbicide use and a better control of C. bengalensis and B. plantaginea. Where the management system obtained control above 97% (Ml e M4) the half fomesafen dose (125 g/ha) provided a satisfactory control of C. benghalensis. The sulfosate and paraquat/diuron+diquat sequences al\owed the management of C. benghalensis

Controle de plantas daninhas na cultura do girassol com aclonifen aplicado isolado ou em mistura

The aim of this work was to evaluate the selectivity and the efficacy of ac1onifen, isolated or in mixture with other herbicides, in postemergence weed control in a sunflower crop. The experiment was conducted in 1998/99, at the Experimental Farm ofMaringá State University, Paraná State, using the hybrid Morgan 742. The experimental design was randomized block with nine treatrnents and four replications. The evaluated treatments were: control (with and without hoeing), aclonifen (780 and 900 g/ha), quizalofop-p-ethy (75 g/ha), aclonifen +quizalofop-p-ethy (900 +75 and 900 + 100 g/ha), aclonifen +fomesafen (900 +25 g/ha) and aclonifen +chlorimuron-ethyl (900 + 2.5 g/ha). The treatments were applied when the sunflower plants were in V6 to V8, using a carbon dioxide-pressurized backpack sprayer, with a spray volume of 200 Llha. The mixtures of aclonifen + quizalofop-p-ethyl and the quizalofop-p-ethyl alone were seletive for sunflower and efficient in Cenchrus echinatus control, not differing significantly for the control. Ac1onifen.alone or in mixture with fomesafen, chlorimuron-ethyl and quizalofop-pethyl were efficient in the control of Commelina benghalensis and Portulaca oleracea not showing differences between these treatments and the control. Aclonifen alone or in mixture with fomesafen and chlorimuron-ethyl did not cause visual injury to the sunflower crop. The presence of weeds, especially C. echinatus, hindered the harvest and decreased the sunflower yield up to 50.0%. O trabalho teve como objetivo avaliar a seletividade e a eficácia do ac1onifen, isolado ou em mistura com outros herbicidas, no controle em pós-emergência de plantas daninhas na cultura do girassol. O experimento foi conduzido na Fazenda Experimental da Universidade Estadual de Maringá, PR, na safra 1998/99, utilizando o híbrido Morgan 742. O delineamento experimental utilizado foi blocos ao acaso, com nove tratamentos e quatro repetições. Os tratamentos avaliados foram: testemunha sem capina, testemunha capinada, aclonifen (780 e 900 glha), quizalofop-p-ethyl (75 g/ha), aclonifen + quizalofop-p-ethyl (900 +75 e 900 + 100 g/ha), aclonifen +fomesafen (900 +25 glha) e aclonifen +chlorimuron-ethyl (900 +2,5 g/ha). Os tratamentos químicos foram aplicados quando o girassol encontrava-se no estádio V6 a V8, utilizando pulverizador costal pressurizado à base de CO , que proporcionou um consumo de calda de 200 Llha. As misturas de aclonifen +quizalofop-p-ethy 1e o quizalofopp- ethyl isolhdo foram seletivos ao girassol e excelentes no controle de Cenchrus echinatus, não diferindo significativamente da testemunha capinada. O aclonifen isolado ou em mistura com fomesafen, chlorimuron-ethyl e quizalofop-p-ethyl foi excelente no controle de Commelina benghalensis e Portulaca oleracea, não havendo diferenças entre estes tratamentos e a testemunha capinada. O aclonifen isolado ou em mistura com fomesafen e chlorimuron-ethyl não causou injúrias visuais ao girassol. A convivência das plantas daninhas, principalmente de C. echinatus, dificultou a colheita e reduziu a produtividade do girassol em 50,0%.

Weed control and selectivity of diclosulam as a preemergence soybean herbicide

O presente trabalho foi resultado de dois experimentos. O primeiro foi conduzido em Iguaraçu, PR, onde foram avaliadas doses de diclosulam (30,35 e 40 g1ha), além de imazaquin (140 g1ha), flumetsulam (108 g1ha) e testemunha sem capina, em um delineamento esperimental de blocos ao acaso, com 4 repetições. Diclosularn controlou eficientemente a poácea Pennisetum typhoideum apenas até 42 dias após a aplicação (DAA), necessitando uma aplicação complementar de um graminicida em pós-emergência para que o controle fosse adequado até a colheita. Para Commelina benghalensis, diclosulam a 30 g/ha promoveu 89% de controle aos 63 DAA. Para latifoliadas como Raphanus raphanistrum e Sida rhombifolia, diclosulam proporcionou um bom controle (>97%) a partir da menor dose, sendo igualou superior aos tratamentos com imazaquin e flumetsulam, até a colheita. No segundo experimento, realizado em Maringá, PR, avaliou-se a mistura de diclosulam com metolachlor, uma vez que diclosulam isoladamente não proporcionou controle adequado de poáceas infestantes, até o final do ciclo da soja. Diclosulam, a partir de 25 g/ha, isolado ou em mistura com metolachlor (~1200 g1ha), controlou bem (~93%) as invasoras C. benghalensis, Euphorbia heterophylla e Desmodium tortuosum, não havendo diferença significativa entre doses. Não foi possível avaliar o efeito de controle da mistura sobre poáceas em função da ausência de infestação na área.The present research involved two field experiments. The first one, carried out at Iguaraçu, PR, inc1uded rates of diclosularn (30,35 and 40 g1ha), imazaquin (140 g/ha), flumetsulam (108 g1ha) and a weed-free control were evaluated in a completely randomized block design with four replications. Diclosulam provided efficient control ofthe grass Pennisetum typhoideum up to 42 days after application (DAA), requiring a suplementary postemergence grass herbicide to al\ow suitable control at harvest. In relation to Commelina bengalensis, diclosulam at 30 g1ha provided 89% control at 63 DAA. For broadleaves like Raphanus raphanistrum and Sida rhombifolia, diclosulam provided good control (>97%) even at the lowest rate, being similar or superior in relation to imazaquin and flumetsulam at harvest. Since diclosulam alone did not provide suitable grass control until harvest, in the second experiment the mixture of diclosulam and metolachor was evaluated. Diclosulam, at 25 g/ha, alone or with metolachor (~1200 glha) provided good control (~93%) of C. benghalensis, Euphorbia heterophylla and Desmodium tortuosum, with no significant differences among evaluated combination of rates. It was not possible to evaluate the efficacy of the combined application of diclosulam and metolachor on grass weed control due to absence of infestation.

Simplified sewerage to prevent urban leptospirosis transmission: a cluster non-randomised controlled trial protocol in disadvantaged urban communities of Salvador, Brazil.

INTRODUCTION: Leptospirosis is a globally distributed zoonotic and environmentally mediated disease that has emerged as a major health problem in urban slums in developing countries. Its aetiological agent is bacteria of the genus Leptospira, which are mainly spread in the urine of infected rodents, especially in an environment where adequate sanitation facilities are lacking, and it is known that open sewers are key transmission sources of the disease. Therefore, we aim to evaluate the effectiveness of a simplified sewerage intervention in reducing the risk of exposure to contaminated environments and Leptospira infection and to characterise the transmission mechanisms involved. METHODS AND ANALYSIS: This matched quasi-experimental study design using non-randomised intervention and control clusters was designed to assess the effectiveness of an urban simplified sewerage intervention in the low-income communities of Salvador, Brazil. The intervention consists of household-level piped sewerage connections and community engagement and public involvement activities. A cohort of 1400 adult participants will be recruited and grouped into eight clusters consisting of four matched intervention-control pairs with approximately 175 individuals in each cluster in baseline. The primary outcome is the seroincidence of Leptospira infection assessed through five serological measurements: one preintervention (baseline) and four postintervention. As a secondary outcome, we will assess Leptospira load in soil, before and after the intervention. We will also assess Leptospira exposures before and after the intervention, through transmission modelling, accounting for residents' movement, contact with flooding, contaminated soil and water, and rat infestation, to examine whether and how routes of exposure for Leptospira change following the introduction of sanitation. ETHICS AND DISSEMINATION: This study protocol has been reviewed and approved by the ethics boards at the Federal University of Bahia and the Brazilian National Research Ethics Committee. Results will be disseminated through peer-reviewed publications and presentations to implementers, researchers and participating communities. TRIAL REGISTRATION NUMBER: Brazilian Clinical Trials Registry (RBR-8cjjpgm)