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.

Sorption and desorption of indaziflam degradates in several agricultural soils

Processes regulating pesticide fate in the environment are influenced by the physicochemical properties of pesticides and soils. Sorption and desorption are important processes as they regulate the movement of pesticides in soil. Although sorption-desorption is widely studied for herbicides, studies involving their metabolites in soil are scarce. Sorption and desorption of indaziflam metabolites (indaziflam-triazinediamine (FDAT), indaziflam-triazine-indanone (ITI) and indaziflam-carboxilic acid (ICA)) were investigated in six Brazilian (BRA) soils and three United States (USA) soils with different physicochemical properties. The Freundlich equation described sorption of the metabolites for all soils (R2 >; 0.98; 1/n ~ 1). Sorption order (Kf) was ITI >; ICA >; FDAT. Mean values of Kf,oc were 453, 289, and 81 (BRA) and 444, 48, and 48 (USA) for metabolites ITI, ICA, and FDAT respectively. Desorption was hysteretic for all metabolites in all soils. These results suggest that these metabolites fall in the classification range of mobile to moderately mobile in soils

Fomesafen selectivity sprayed in preemergence of different cultivars of cotton

Sabe-se que existem diferenças entre as cultivares de algodoeiro em relação as injúrias causadas por herbicidas aplicados em pré-emergência. Desta forma, o trabalho foi conduzido, em casa de vegetação, com o objetivo de avaliar o efeito de doses crescentes do herbicida fomesafen sobre o crescimento inicial de oito cultivares de algodoeiro. O delineamento experimental utilizado foi o inteiramente casualizado arranjado em esquema fatorial 8 x 6, com cinco repetições. Avaliou-se a resposta de oito cultivares de algodoeiro (DP 555 BG RR, FMT 705, FMT 701, FM 910, FM 966 LL, FM 993, IMA CD 6001 LL e IMA 8221) a seis doses do herbicida fomesafen (0, 125, 250, 375, 500 e 625 g ha-1 de ingrediente ativo - i.a.) em aplicação de pré-emergência, logo após a semeadura, que foi realizada a 3 cm de profundidade. O solo utilizado nos vasos foi um Latossolo Vermelho distrófico de classe textural franco-argilo-arenosa, pH de 5,9; 2,94% de MO, 320 g kg-1 de argila e 600 g kg-1 de areia. As variáveis avaliadas foram porcentagem de fitointoxicação aos 5, 10 e 20 dias após a aplicação, além da massa seca da parte aérea aos 30 dias após a aplicação. Concluiu-se que as cultivares de algodoeiro respondem de maneira diferente à aplicação do herbicida fomesafen em pré-emergência. A cultivar mais tolerante a este herbicida foi a FMT 705. As cultivares mais sensíveis foram IMA CD 6001 LL, FMT 701 e FM 993.There is an outstanding difference among cotton cultivar related to injury caused by herbicides applied in preemergence. This way, the present work was conduct in greenhouse with the objective to evaluate the effect of crescent doses to fomesafen about the initial growth to eight cotton cultivars. The experimental design utilized was the completely randomized, arranged in factorial design 8 x 6, with five replications. Evaluate the response of eight cotton cultivars (DP 555 BG RR, FMT 705, FMT 701, FM 910, FM 966 LL, FM 993, IMA CD 6001 LL e IMA 8221) to six doses to fomesafen herbicide (0, 125, 250, 375, 500 e 625 g ha-1 a.i.), applied in preemergence, after the sowing, that was realized in three centimeters of deep. The soil utilized was red Oxisol, pH of 5.9, 2.94% of M.O., 320 g kg-1 of clay and 600 g kg-1 of sand. The variables evaluated was phytointoxication percentage at 5, 10 and 20 days after application, besides to dry weight of shoot 30 days after application. Conclude that cotton cultivars response of the different way to fomesafen applied in preemergence. The cultivar most tolerant was FMT 705. The most sensible cultivars were IMA CD 6001 LL, FMT 701 and FM 993

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.

Efetividade de herbicidas no controle de Alternanthera tenella

The objective of this work was to evaluate the efficacy of different herbicides, applied both at pre and post-emergence, to control Alternanthera tenella. Two assays were accomplished: the first one for pre-emergence herbicides, and the second one for post-emergence herbicides, applied at two pair of leaves stage. Pre-emergence herbicide treatments and respective rates (g i.a. ha-1) were: alachlor (2880); chlorimuron-ethyl (15); metribuzin (576); clomazone (1000); flumetsulam (120); sulfentrazone (600); trifluralin (540); amicarbazone (1050); pendimethalin (1500); oxyfluorfen (360); ametryn (1500); diuron (1500); imazapic (140); isouron (175); s-metolachlor (576 and 960) and check plot. Post-emergence herbicide treatments were: fomesafen (250); [diuron+paraquat] [200+400]; 2,4-D (1005); carfentrazone-ethyl (60); chlorimuron-ethyl (15); lactofen (168); bentazon (720); flumiclorac-pentyl (60); [glyphosate+imazethapyr] [444,5+75]; diquat (400); glyphosate (540 and 1440) and check plot. For pre-emergence applications, all herbicides were considered efficient for A. tenella control, propitiating more than 98% control at 28 days after application (DAA). The post-emergence herbicide treatments, fomesafen, lactofen and bentazon did not control A. tenella. Remaining post-emergence treatments provided more than 97% control of A. tenella at 28 DAA.O objetivo deste trabalho foi avaliar a eficácia de diferentes herbicidas, aplicados em pré e pós-emergência, no controle de Alternanthera tenella. Foram realizados dois ensaios em casa-de-vegetação: no primeiro, foram avaliados herbicidas aplicados em pré-emergência, e no segundo foram avaliados herbicidas em pós-emergência, aplicados quando a planta daninha apresentava dois pares de folhas. Os tratamentos em pré-emergência e as respectivas doses (g ha-1) avaliadas foram: alachlor (2880); chlorimuron-ethyl (15); metribuzin (576); clomazone (1000); flumetsulam (120); sulfentrazone (600); trifluralin (540); amicarbazone (1050); pendimethalin (1500); oxyfluorfen (360); ametryn (1500); diuron (1500); imazapic (140); isouron (175); s-metolachlor (576 e 960) e testemunha sem aplicação. Os tratamentos avaliados em pós-emergência foram: fomesafen (250); [diuron+paraquat][200+400]; 2,4-D (1005); carfentrazone-ethyl (60); chlorimuron-ethyl (15); lactofen (168); bentazon (720); flumiclorac-pentyl (60); [glyphosate+imazethapyr][444,5+75]; diquat (400); glyphosate (540 e 1440) e testemunha sem aplicação. Nas aplicações em pré-emergência, todos os herbicidas foram considerados eficazes para o controle de A. tenella, proporcionando controle acima de 98% aos 28 dias após aplicação (DAA). Os resultados das aplicações pós-emergentes demonstraram que os herbicidas fomesafen, lactofen e bentazon não foram eficazes no controle de A. tenella. Os demais herbicidas aplicados em pós-emergência foram altamente eficazes, resultando num controle acima de 97% aos 28 DAA

Selectivity of pre-and post-emergence herbicides to very-early maturing soybean cultivars

The combination of pre- and post-emergence herbicides may affect their selectivity to soybean plants, especially to short-cycle cultivars. The objective of this work was to evaluate the selectivity of pre- and post-emergence herbicides to very-early maturing soybean cultivars. Two field experiments were conducted, one in Mandaguaçu, Paraná (E1) and other in Rio Verde, Goiás (E2), Brazil, using a 4×7 factorial arrangement. The treatments consisted of four pre-emergence herbicide managements (S-metolachlor at 1440 g ha-1, diclosulam at 25.2 g ha-1, sulfentrazone at 300 g ha-1, and no herbicide application); and seven post-emergence herbicide managements (lactofen at 120 g ha-1, chlorimuron-ethyl at 12.5 g ha-1, bentazon at 720 g ha-1, lactofen at 120 g ha-1 + chlorimuron-ethyl at 12.5 g ha-1, glyphosate at 900 g a. e. ha-1, two sequential glyphosate applications at 720 g a. e. ha-1 each, and no herbicide application). The early-maturing soybean cultivars evaluated showed sensitivity to the herbicides used. The combined use of pre- and post-emergence herbicides increased the occurrence of injuries in the plants. Diclosulam and sulfentrazone were the least selective pre-emergence herbicides. All herbicide combinations used affected soybean grain yield in E1; lactofen, chlorimuron, and bentazon presented the least selectivity in E2.The combination of pre- and post-emergence herbicides may affect their selectivity to soybean plants, especially to short-cycle cultivars. The objective of this work was to evaluate the selectivity of pre- and post-emergence herbicides to very-early maturing soybean cultivars. Two field experiments were conducted, one in Mandaguaçu, Paraná (E1) and other in Rio Verde, Goiás (E2), Brazil, using a 4×7 factorial arrangement. The treatments consisted of four pre-emergence herbicide managements (S-metolachlor at 1440 g ha-1, diclosulam at 25.2 g ha-1, sulfentrazone at 300 g ha-1, and no herbicide application); and seven post-emergence herbicide managements (lactofen at 120 g ha-1, chlorimuron-ethyl at 12.5 g ha-1, bentazon at 720 g ha-1, lactofen at 120 g ha-1 + chlorimuron-ethyl at 12.5 g ha-1, glyphosate at 900 g a. e. ha-1, two sequential glyphosate applications at 720 g a. e. ha-1 each, and no herbicide application). The early-maturing soybean cultivars evaluated showed sensitivity to the herbicides used. The combined use of pre- and post-emergence herbicides increased the occurrence of injuries in the plants. Diclosulam and sulfentrazone were the least selective pre-emergence herbicides. All herbicide combinations used affected soybean grain yield in E1; lactofen, chlorimuron, and bentazon presented the least selectivity in E2

Carryover de herbicidas utilizados no controle de soqueiras do algodoeiro sobre o milho cultivado em sucessão

Information about the residual activity of herbicides sprayed in the control of cotton stalks and its potential to affect the development and productivity of corn sown in the following crop are limited. The objective of this work was to identify the carryover effect promoted by the single and sequential application of herbicides used in the control of cotton stalks and to estimate the plant-back for corn sowing. Two trials were carried out simultaneously in a greenhouse, one for a single application and one for a sequential application of herbicides treatments. It was used a 15 x 5 factorial scheme, in a randomized block design with four replicates. The first factor was composed of herbicide treatments and the second factor of five sowing seasons after the application (0, 30, 60, 90 and 120 days). The experimental plots were composed of plastic pots with a capacity of 3 dm3 filled with loamy soil (470 g kg-1 clay), dried and sieved. The herbicides sprayed were 2,4-D, glyphosate, saflufenacil, [imazapic + imazapyr], dicamba, fluroxypyr, and sulfentrazone. The sequential application of most treatments provided an increase in the residual activity of the evaluated herbicides. The 2,4-D (1,340 g ha-1), 2,4-D + glyphosate (1,340 + 720 g ha-1) and 2,4-D + glyphosate + saflufenacil (1,340 + 720 + 105 g ha-1) presented the shortest safety intervals and were those that presented the lowest risk of affecting the corn sown in succession, even in sequential applications. However, the treatments that consisted of association with herbicides with higher residual activity in the soil such as dicamba, fluroxypyr, sulfentrazone and [imazapic + imazapyr], presented higher carryover potential for corn crop, being observed a safety interval greater than 94 days after sequential application of 2,4-D + glyphosate + sulfentrazone.São limitadas as informações sobre a atividade residual de herbicidas aplicados no controle das soqueiras do algodoeiro e o seu potencial para afetar o desenvolvimento e a produtividade do milho semeado na safra seguinte. O objetivo desse trabalho foi identificar o efeito carryover promovido pela aplicação única e sequencial de herbicidas utilizados no controle das soqueiras do algodoeiro e estimar o intervalo de segurança entre o manejo químico da soqueira do algodoeiro e a semeadura do milho. Foram conduzidos simultaneamente dois experimentos em casa de vegetação, um para aplicação única e outro para aplicação sequencial dos tratamentos herbicidas. Os experimentos foram instalados em esquema fatorial 15 x 5, delineados em blocos casualizados com quatro repetições. O primeiro fator foi composto por tratamentos herbicidas e o segundo fator por cinco épocas de semeadura do milho após a aplicação (0, 30, 60, 90 e 120 dias). As parcelas experimentais foram compostas de vasos plásticos com capacidade para 3 dm3 preenchidos com solo de textura argilosa (470 g kg-1 de argila), seco e peneirado. Os herbicidas utilizados foram 2,4-D, glyphosate, saflufenacil, [imazapic+imazapyr], dicamba, fluroxypyr e sulfentrazone. Conclui-se que a aplicação sequencial da maioria dos tratamentos proporcionou um aumento na atividade residual dos herbicidas avaliados. Os tratamentos 2,4-D (1340 g ha-1), 2,4-D + glyphosate (1340 + 720 g ha-1) e 2,4-D + glyphosate + saflufenacil (1340 + 720 + 105 g ha-1) apresentaram os menores intervalos de segurança e foram aqueles que apresentaram o menor risco de afetar o milho semeado em sucessão, mesmo em aplicações sequenciais. Contudo, os tratamentos constituídos pela associação com herbicidas de maior atividade residual no solo como o dicamba, fluroxypyr, sulfentrazone e [imazapic+imazapyr], apresentaram maior potencial de carryover para a cultura do milho, sendo observado intervalo de segurança superior a 94 dias após a aplicação sequencial de 2,4-D + glyphosate + sulfentrazone

Development And Grain Quality Of Soybean Cultivars Treated With Pyraclostrobin And Biostimulant

Products with physiological effects on plants to optimize agricultural production is increasingly used; they can change the development of plants and the chemical characteristics of seeds. The objective of this work was to evaluate the development of soybean cultivars and the protein and oil contents of soybean grains after treatment with pyraclostrobin and biostimulant. The experiment was carried out with soybean crops without irrigation. The experimental design was a randomized complete block design, with five replications, using a 3 × 3 factorial arrangement consisting of three cultivars of different maturation times (very early, M6952IPRO; early M7739IPRO; and medium, ST797IPRO), and three treatments with products that cause physiological effects (control, pyraclostrobin, and control + biostimulant). The pod, leaf, and stem dry weights, number of pods, 100-grain weight, grain yield, and oil and protein contents of the soybean plants were evaluated. The data were subjected to analysis of variance, and Tukey’s test at 5% probability. The effects of the products used (pyraclostrobin and biostimulant) vary according to the cultivar and may increase the soybean leaf and pod dry weights, and grain protein contents.Products with physiological effects on plants to optimize agricultural production is increasingly used; they can change the development of plants and the chemical characteristics of seeds. The objective of this work was to evaluate the development of soybean cultivars and the protein and oil contents of soybean grains after treatment with pyraclostrobin and biostimulant. The experiment was carried out with soybean crops without irrigation. The experimental design was a randomized complete block design, with five replications, using a 3 × 3 factorial arrangement consisting of three cultivars of different maturation times (very early, M6952IPRO; early M7739IPRO; and medium, ST797IPRO), and three treatments with products that cause physiological effects (control, pyraclostrobin, and control + biostimulant). The pod, leaf, and stem dry weights, number of pods, 100-grain weight, grain yield, and oil and protein contents of the soybean plants were evaluated. The data were subjected to analysis of variance, and Tukey’s test at 5% probability. The effects of the products used (pyraclostrobin and biostimulant) vary according to the cultivar and may increase the soybean leaf and pod dry weights, and grain protein contents