Eficácia de herbicidas aplicados em trapoeraba (Commelina benghalensis) na região oeste do Estado do Paraná

Ragweed (Commelina spp.) is considered a genus tolerant to glyphosate, with reduced control of this herbicide in advanced stages. Thus, the aim of this study was to evaluate the effectiveness of controlling associations of glyphosate with herbicides with different mechanisms of action in Commelina benghalensis. The experiment was carried out, after the harvest of the off-season corn in 2018, in Palotina-PR. The experimental design was randomized blocks with 12 treatments (Control, glyphosate + 2,4-D, glyphosate + 2,4-D (aminol 806), glyphosate + dicamba, saflufenacil + glyphosate, glyphosate + dicamba + saflufenacil, diclosulam + glyphosate + saflufenacil, glyphosate + dicamba + chlorimuron, glyphosate + dicamba + glufosinate, glyphosate + dicamba + diclosula, glyphosate + dicamba + (sulfentrazone + diuron) and glyphosate + dicamba + (imazethapyr + flumioxazin) and 4 replicates. 7, 14, 21 and 28 days after application (DAA) and through dry mass at 28 DAA. Regardless of the treatment, at 7 DAA there was no effective control. The scores increased over time, and at 28 DAA, treatments glyphosate + 2,4-D for both doses (1025+975 and 1080+1005); diclosulam + glyphosate + saflufenacil; glyphosate + dicamba + diclosulam and glyphosate + dicamba + (imazethapyr + flumioxazin) were the most effective in the control and reduction of dry mass, reducing the possible associations in the control of ragweed.A trapoeraba (Commelina spp.) é considerada um gênero tolerante ao glyphosate, apresentando controle reduzido a esse herbicida em estádios avançados. Assim, o objetivo do trabalho foi avaliar a eficácia de controle das associações de glyphosate com herbicidas de diferentes mecanismos de ação em Commelina benghalensis. O experimento foi conduzido, após a colheita do milho safrinha em 2018, em Palotina-PR. O delineamento experimental foi de blocos casualizados com 12 tratamentos (Testemunha, glyphosate + 2,4-D, glyphosate + 2,4-D (aminol 806), glyphosate + dicamba, saflufenacil + glyphosate, glyphosate + dicamba + saflufenacil, diclosulam + glyphosate + saflufenacil, glyphosate + dicamba + chlorimuron, glyphosate + dicamba + glufosinato, glyphosate + dicamba + diclosula, glyphosate + dicamba + (sulfentrazona + diuron) e glyphosate + dicamba + (imazetapir + flumioxazina) e 4 repetições. O controle de C. benghalensis foi avaliado por notas visuais aos 7, 14, 21 e 28 dias após a aplicação (DAA) e por meio da massa seca aos 28 DAA. Independente do tratamento, aos 7 DAA não houve controle eficaz. As notas foram crescentes ao longo do tempo, sendo que aos 28 DAA, os tratamentos glyphosate + 2,4-D para ambas as doses (1025+975 e 1080+1005); diclosulam + glyphosate + saflufenacil; glyphosate + dicamba + diclosulam e glyphosate + dicamba + (imazetapir + flumioxazina) foram os mais eficazes no controle e redução de massa seca, indicando ser potenciais associações no controle da trapoeraba

RR2 corn and glyphosate: A review

Os benefícios resultantes da tecnologia Roundup Ready são expressivos, e a aceitação desta tecnologia pelos produtores rurais é inegável, dando suporte para o rápido crescimento das áreas de milho RR2. Ao mesmo tempo resultados de pesquisas recentes indicam que o glyphosate aplicado em pós-emergência, em milho RR2, pode, em algumas situações, causar danos ao desenvolvimento das plantas. Porém, persistem muitas especulações e dúvidas que precisam ser melhores elucidadas, no âmbito científico e técnico. Em virtude deste fato, faz-se necessária a busca de informações que permitam diagnosticar as reais consequências do uso do glyphosate nesta cultura. E assim, fomentar o posicionamento mais seguro e sustentável desta nova tecnologia, proporcionando aos agricultores benefícios relacionados ao manejo adequado de plantas daninhas nos diversos agroecossistemas.The benefits of the Roundup Ready technology are expressive and the acceptance of this technology by farmers is undeniable, giving support to the rapid growth of RR2 corn. Recent studies indicate, however, that glyphosate applied in post-emergence in RR2 corn can eventually cause damage to plant development. Therefore, there are many speculations and questions that need to be clarified in the scientific and technical context glyphosate. Thus, it is necessary the search for information allowing to diagnose the real consequences of its use. And thus foster safer and sustainable positioning of this new technology, providing benefits to farmers related to proper weed management in different agroecosystems

POTENTIAL SELECTIVITY OF HERBICIDES IN PRE- AND POST-EMERGENT LINSEED (LINUM USITATISSIMUM L.)

A linhaça é uma oleaginosa amplamente utilizada na alimentação humana e animal, como cultura de cobertura em agroecossistemas e para produção de fibras. Para facilitar o manejo de plantas daninhas na cultura, este trabalho teve como objetivo avaliar potenciais herbicidas seletivos para o cultivo de linhaça aplicados em pré-plantio incorporado (PPI), pré-emergência (PRE), pós-emergência inicial (POS), pós-emergência tardia (POS tardio) uma vez que ainda não existem herbicidas registrados para uso em linhaça no Brasil. Portanto, quatro experimentos foram conduzidos em delineamento inteiramente casualizado com quatro repetições, e cinco (exp. 1), 21 (exp. 2), 26 (exp. 3) e quatro (exp. 4) tratamentos. Foram avaliadas a injúria na cultura e a matéria fresca e seca das plantas. O Experimento 4 foi conduzido até a produção de sementes, obtendo-se os dados de altura final, número de cápsulas e produtividade. Os resultados foram caracterizados pela baixa seletividade dos herbicidas durante a pré-emergência, incorporados ou não, e indicaram 11 herbicidas com potencial seletividade na pós-emergência, seja precoce ou tardia, os quais foram: bentazon, bentazon + imazamox, clethodim + fenoxaprop, clethodim, flumiclorac, fluazifop, flumioxazin, haloxyfop, nicosulfuron, tembotrione e tepraloxydim. A linhaça demonstrou ser suscetível ou com baixa tolerância a vários herbicidas.Linseed is an oilseed crop that is widely used in human and animal feed, as a cover crop in agroecosystems, and for fiber production. To facilitate the management of weeds in the crop, this study aimed to evaluate potential selective herbicides for linseed cultivation applied in pre-planting and incorporation (PPI), pre-emergence (PRE), and early (POST) and late (late POST) post-emergence stages, since there are presently no herbicides registered for use on linseed in Brazil. Therefore, four experiments were conducted in a completely randomized design with four replications, and five (exp. 1), 21 (exp. 2), 26 (exp. 3), and four (exp. 4) treatments. Crop injury and the fresh and dry matter of the plants were evaluated. Experiment 4 was conducted until seed production, and data on the final height, number of capsules, and yield were obtained. The results were characterized by the low selectivity of herbicides during pre-emergence, whether incorporated or not, and indicated 11 herbicides with potential selectivity in post-emergence, whether early or late, namely: bentazon, bentazon + imazamox, clethodim + fenoxaprop, clethodim, flumiclorac, fluazifop, flumioxazin, haloxyfop, nicosulfuron, tembotrione, and tepraloxydim. Linseed is demonstrated to be susceptible to or has low tolerance to various herbicides

Performance of intacta soybean cultivars in Marechal Cândido Rondon, Western Paraná State

The soybean, one of the most important cultures in Brazilian agriculture, is a profitable culture due to the use of brand new technologies in the development of new cultivars, which contain more and more biotechnologies that turn the crop management easier. Among these technologies, there is the INTACTA RR2 PRO®, which was recently released. However, there are few studies to show the most yielding cultivars indicated to Marechal Cândido Rondon. So, the aim of this study was to evaluate some cultivars indicated to this region and then recommend them to the farmers. A couple of agronomic characteristics were evaluated, focusing in the yield and cycle. The randomized block design was used, with four replications. The obtained data was submitted to variance analysis and the averages were compared following the Tukey Test (p≤0,05). The results indicate that the cultivars with the shortest cycles are more adapted and provided the highest yields in the region.The soybean, one of the most important crops in Brazilian agriculture, is a profitable crop due the use of new technologies in the development of new cultivars, which contain more biotechnologies that turn its management easier. Among these technologies, there is the INTACTA RR2 PRO®, which was recently released. However, there are few studies to show the most yielding cultivars indicated to Marechal Cândido Rondonm,Paraná State, Brazil. Therefore, the aim of this study was to evaluate the performance of some IPRO soybean cultivars recommended or cultivated in Western Paraná and identify the most yielding ones. A couple of agronomic characteristics were evaluated, focusing in the yield and cycle. The randomized block design was used, with four replications. The data was submitted to variance analysis and the averages were compared following the Tukey Test (p ≤ 0.05). The results indicate that the cultivars with the shortest cycles are more adapted and provided the highest yields in the region

Efeito residual de clethodim aplicado em pré-semeadura do milho

Brazil is one of the few countries where it is possible to produce more than one crop in the same agricultural year, and the soybean-corn succession is practiced by most of the producers. This cultural system provided the selection of weeds resistant to herbicides, mainly by the use of herbicides with the same mechanism of action in successive crops. In this scenario, new management strategies should be adopted, such as herbicide applications in corn pre-sowing. The objective of this search was to evaluate the influence of periods of application of clethodim on pre-sowing, on emergence and initial development of maize hybrids. For this, the residual effect of clethodim on hybrid 2B810 Power Core, Status Viptera 3, Dekalb 340 VT PRO2 with application of clethodim 196.80 g L-1 a.i. at 15, 10, 5, 3 and 1 day before sowing (DBS) of corn and a control without application. The variables analyzed were: emergence, plant height, falker chlorophyll index, stalk diameter, fresh and dry matter accumulation. The application of clethodim 1 day before sowing adversely affected the emergence and initial development of evaluated corn hybrids. The hybrids presented differential susceptibility to the residual of clethodim for emergence variables, accumulation of fresh matter and dry matter accumulation.O Brasil é um dos poucos países onde é possível realizar mais de uma safra no mesmo ano agrícola, sendo a sucessão soja-milho praticada por grande parte dos produtores. Este sistema cultural proporcionou a seleção de plantas daninhas resistentes à herbicidas, principalmente pela utilização de herbicidas com mesmo mecanismo de ação em sucessivos cultivos. Neste cenário, novas estratégias de manejo devem ser adotadas, como aplicações de herbicidas em pré-semeadura do milho. O objetivo deste trabalho foi avaliar a influência de períodos de aplicação de clethodim em pré-semeadura, sobre a emergência e desenvolvimento inicial de híbridos de milho. Para tal, avaliou-se o efeito residual de clethodim sobre híbridos 2B810 Power Core, Status Viptera 3, Dekalb 340 VT PRO2 com aplicação de clethodim 196,80 g L-1 i.a. aos 15, 10, 5, 3 e 1 dias antecedendo a semeadura (DAS) do milho e uma testemunha sem aplicação. As variáveis analisadas foram: emergência, altura de plantas, índice de clorofila falker, diâmetro de colmo, acúmulo de matéria fresca e seca. A aplicação de clethodim 1 dia antecedendo a semeadura afetou negativamente a emergência e o desenvolvimento inicial dos híbridos de milho avaliados. Os híbridos apresentaram suscetibilidade diferencial ao residual de clethodim para as variáveis emergência, acúmulo de matéria fresca e acúmulo de matéria seca

Taxas de aplicação e herbicidas no controle de plantas daninhas em pastagem

Pastures formed with Cynodonn lemfuensis Vanderyst are excellent alternatives for feeding livestock. The competition from weeds can cause damage to pasture, and Vernonia polyanthes and Desmodium incanum are among the main competing species. The objective of this study was to evaluate the efficacy of different herbicides to control Vernonia polyanthes and Desmodium incanum, applied in high and low spray mix volumes. The experiment was established in an area formed for over 10 years by African stargrass (Cynodonn lemfuensis). The experimental design was a randomized block in a 2x7 factorial arrangement with two spray mix volumes of 50 and 200 L ha-1 and seven herbicides. Variables phytotoxicity on grass Cynodonn lemfuensis at 3, 7, 14, 21 and 28 days after application (DAA) and control of weed plants Vernonia polyanthes and Desmodium incanum at 7, 14, 21 and 28 DAA were evaluated. There were no high levels of phytotoxicity in the pasture. The treatments that provided the best controls of Vernonia polyanthes and Desmodium incanum were fluroxypyr-meptyl + triclopyr, 2,4 D + aminopyralid and 2,4 D + picloram. Spray mix volumes provided no significant differences in the evaluation of control after 28 DAA for herbicides, but were higher for some treatments at 7, 14 and 21 DAA. Thus, the lowest volume of spray mix (50 L ha-1) becomes a viable alternative in the control of these species in the pasture.Pastagens formadas com Cynodonn lemfuensis Vanderyst são excelentes alternativas para alimentação dos rebanhos. A competição de plantas daninhas pode ocasionar prejuízos à pastagem, sendo que Vernonia polyanthes e Desmodium incanum estão entre as principais espécies competidoras. O objetivo do presente trabalho foi avaliar a eficácia de diferentes herbicidas no controle de Vernonia polyanthes e Desmodium incanum, aplicados em alto e baixo volume de calda. O experimento foi instalado em uma área formada há mais de 10 anos por grama-estrela-africana (Cynodonn lemfuensis). O delineamento experimental empregado foi o de blocos ao acaso, no esquema fatorial 2x7, sendo dois volumes de calda 50 e 200 L ha-1 e sete herbicidas. Foram avaliadas as variáveis fitotoxicidade na grama Cynodonn lemfuensisaos 3, 7, 14, 21 e 28 dias após a aplicação (DAA) e controle das plantas daninha Vernonia polyanthes e Desmodium incanum aos 7, 14, 21 e 28 DAA. Não foram encontrados níveis altos de fitotoxicidade na pastagem. Os tratamentos que proporcionaram os melhores controles de Vernonia polyanthes e Desmodium incanum foram fluroxypyr meptílico + triclopyr, 2,4 D + aminopiralide e 2,4 D + picloram. Os volumes de calda não proporcionaram diferenças significativas na avaliação de controle aos 28 DAA para herbicidas, porém foram superiores para alguns tratamentos aos 7, 14 e 21 DAA. Com isso o menor volume de calda (50 L ha-1) torna-se uma alternativa viável no controle dessas espécies na pastagem

Effect of forage aqueous extracts on Glycine max L. Merr., Zea mays L. and Bidens pilosa L.

The aim of the present study was to investigate the potential allelopathic effects of isolated or intercropped aqueous forage extracts on the physiological performance of soybean [Glycine max (L.) Merr.] and corn (Zea mays L.) seeds, as well as their phytotoxicity to the weed species Bidens pilosa L. Aqueous extracts were prepared at a concentration of 5%, and the tests with soy and corn were conducted by wetting the germination papers with different treatments and performing procedures within the standards of the Brazilian Rules of Seed Analysis. Tests with the cover plant extracts on the seeds of B. pilosa used BOD-type repetitions. Fifty weed seeds were placed in a gerbox with filter paper moistened with the different treatments with five repetitions. Distilled water was used as the control in all tests. Extracts of Avena strigosa Schreb and Raphanus sativus L. (radish), cultivated individually and in combination, increased the seed germination percentage (%G) and the length of soybean seedlings. Similarly, extracts of Pennisetum glaucum (L.) R.Br and Crotalaria spectabilis Roth, in individual and combined cultivation, provided gains in corn %G. Furthermore, all tested extracts suppressed germination and decreased the speed of the germination index of the hairy beggarticks when compared to the control, with the radish extract showing the greater reduction effect on the %G of the weed plant B. pilosa. Highlights: The use of Crotalaria as a cover crop has a positive effect on the initial growth of corn. The use of black oat and forage radish intercropped had the potential to increase soybean yield. The use of cover crops contributes to the integrated management of weeds. The choice of cover plant is important for the success of crop rotation.The aim of the present study was to investigate the potential allelopathic effects of isolated or intercropped aqueous forage extracts on the physiological performance of soybean [Glycine max (L.) Merr.] and corn (Zea mays L.) seeds, as well as their phytotoxicity to the weed species Bidens pilosa L. Aqueous extracts were prepared at a concentration of 5%, and the tests with soy and corn were conducted by wetting the germination papers with different treatments and performing procedures within the standards of the Brazilian Rules of Seed Analysis. Tests with the cover plant extracts on the seeds of B. pilosa used BOD-type repetitions. Fifty weed seeds were placed in a gerbox with filter paper moistened with the different treatments with five repetitions. Distilled water was used as the control in all tests. Extracts of Avena strigosa Schreb and Raphanus sativus L. (radish), cultivated individually and in combination, increased the seed germination percentage (%G) and the length of soybean seedlings. Similarly, extracts of Pennisetum glaucum (L.) R.Br and Crotalaria spectabilis Roth, in individual and combined cultivation, provided gains in corn %G. Furthermore, all tested extracts suppressed germination and decreased the speed of the germination index of the hairy beggarticks when compared to the control, with the radish extract showing the greater reduction effect on the %G of the weed plant B. pilosa. Highlights: The use of Crotalaria as a cover crop has a positive effect on the initial growth of corn. The use of black oat and forage radish intercropped had the potential to increase soybean yield. The use of cover crops contributes to the integrated management of weeds. The choice of cover plant is important for the success of crop rotation

Metsulfuron-methyl over agronomic performance and seed quality of wheat crop

Na cultura do trigo são escassos os resultados científicos referente ao uso de herbicidas, limitando as informações sobre os efeitos que estes causam. Neste contexto, o objetivo deste trabalho foi avaliar alguns componentes da produção e a qualidade das sementes do trigo sob o efeito da aplicação de doses crescentes de metsulfuron-methyl em dois estádios de desenvolvimento, tendo como pressuposto que o emprego de altas doses em combinação com o estádio de desenvolvimento possa afetar a planta. Com este intuito foi conduzido um ensaio a campo, em que os tratamentos foram compostos por cinco doses do herbicida metsulfuron-methyl: 0; 1,8; 3,6; 5,4; 7,2 g i.a. ha-1; aplicadas em dois estádios da cultura: 4 e 10.4. As variáveis avaliadas foram: produtividade, massa de mil sementes, germinação e vigor. Com base nos resultados obtidos pode-se concluir que o herbicidametsulfuron-methyl pode ser nocivo à cultura do trigo, apenas quando se utiliza o incremento das doses na fase de espigamento.On wheat crop there is scarce scientific evidence regarding the use of herbicides, limiting the information about their effects. In this context, the objective of this work was to evaluate some yield components and seed quality of wheat crop under the effect of increasing doses application of metsulfuron- methyl in two stages of development, from the premise that the use of high doses in combination with developmental stage may affect the plant. With this purpose an experiment was conducted in field conditions, in which treatments consisted of five doses of metsulfuron-methyl herbicide: 0; 1.8; 3.6; 5.4; 7.2 g a.i. ha-1, applied at two crop stages: 4 and 10.4. Variables evaluated were: yield, thousand seed mass, germination and vigor. According to obtained results, it’s possible to conclude that metsulfuron-methyl herbicide may be harmful to wheat crop, only when it is used doses increment at silking stage

SUPRA EXTENSÃO: PROJETO EM SISTEMAS SUSTENTÁVEIS DE PRODUÇÃO AGRÍCOLA

Considerando a complexidade da produção agrícola e a necessidade de sustentabilidade ao atender a demanda alimentar, o objetivo geral foi de construir e aplicar atividades de extensão rural para uma agricultura mais sustentável. Foram desenvolvidas, mesmo em período de pandemia, inúmeras iniciativas práticas, especialmente sistematizadas e aplicadas de forma remota. O trabalho inicialmente focava atividades a campo na região Oeste do Estado do Paraná, mas posteriormente ampliou-se para todos os Estados do Sul, São Paulo e Mato Grosso do Sul, e mesmo alcance internacional (Paraguai). O eixo das atividades, que conciliaram teoria e prática, migraram parcialmente entre as ações em campo e as remotas, atuando no período remoto por meio das mídias sociais e eventos. As operações em conjunto com outros projetos de extensão, com grupo de pesquisa e empresa júnior (E.J.), envolveram inúmeros estudantes e foram coordenadas pelos docentes. Observou-se expressivo impacto, por compartilhamento de informações e interação dialógica, nas redes sociais dos estudantes e professores. No entanto, atenção especial foi dada as redes sociais vinculadas ao Supra Pesquisa (hoje E.J. Supra Pesquisa). Nesse sentido, destaca-se a marcante atuação no Canal do YouTube “Professores Alfredo e Leandro Albrecht” (https://www.youtube.com/c/ProfessoresAlfredoLeandroAlbrecht). A extensão universitária e rural foi viva e impactante, promovendo a indissociabilidade entre ensino, pesquisa e extensão. Gerando transformações no campo e no virtual, mostrando a cara e a significância da Universidade, mesmo em um período complexo, como o da pandemia. Observando que o alcance no período foi superior a 10 mil inscritos nas mídias e redes sociais. O projeto em ação, proporcionou a divulgação cientifica e popularização da ciência e tecnologia, para um desenvolvimento sustentável da produção agroalimentar.

Sequential application of herbicide options for controlling Conyza sumatrensis in soybean pre-sowing

The aim of this study was to evaluate the efficacy of sequentially applied herbicides to control Conyza sumatrensis, one of the most widely distributed weeds worldwide, in soybean pre-sowing burndown. The study was conducted under field conditions in the state of Paraná, Brazil, at 2018-2019 growing season. The experiment consisted of a randomized block design with four replicates, with 12 treatments consisting of different herbicide mixtures applied before sowing. Control of C. sumatrensis, injury to soybean plants, and variables related to agronomic performance were evaluated. The control levels were high for all treatments, except for the one that was free of saflufenacil in either of the two applications. These results highlight the importance of saflufenacil in the control of C. sumatrensis and show promise for the use of saflufenacil/imazethapyr when considering the system and other weeds. All studied treatments were selective to soybean, which showed higher injury values in the presence of diclosulam; however, this did not compromise the agronomic performance of soybean. Highlights • Application of systemic herbicides with sequential application of burndown herbicides, is essential for the control of Conyza sumatrensis (>15 cm height).• Saflufenacil, flumioxazin, and imazethapyr stand out in the control of Conyza sumatrensis.• Protox and ALS inhibitors can replace paraquat in sequential application with equal efficacy in the control of Conyza sumatrensis.The aim of this study was to evaluate the efficacy of sequentially applied herbicides to control Conyza sumatrensis, one of the most widely distributed weeds worldwide, in soybean pre-sowing burndown. The study was conducted under field conditions in the state of Paraná, Brazil, at 2018-2019 growing season. The experiment consisted of a randomized block design with four replicates, with 12 treatments consisting of different herbicide mixtures applied before sowing. Control of C. sumatrensis, injury to soybean plants, and variables related to agronomic performance were evaluated. The control levels were high for all treatments, except for the one that was free of saflufenacil in either of the two applications. These results highlight the importance of saflufenacil in the control of C. sumatrensis and show promise for the use of saflufenacil/imazethapyr when considering the system and other weeds. All studied treatments were selective to soybean, which showed higher injury values in the presence of diclosulam; however, this did not compromise the agronomic performance of soybean. Highlights • Application of systemic herbicides with sequential application of burndown herbicides, is essential for the control of Conyza sumatrensis (>15 cm height).• Saflufenacil, flumioxazin, and imazethapyr stand out in the control of Conyza sumatrensis.• Protox and ALS inhibitors can replace paraquat in sequential application with equal efficacy in the control of Conyza sumatrensis