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Made available in DSpace on 2021-06-25T10:23:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Universidade Federal do Paraná One of the factors that limit grain yield in soybean crops is weed competition. The objective of the present work was to evaluate the agronomic performance of an AHAS-transgene soybean cultivar (BRS 397; Cultivance®) subjected to different rates of Soyvance® (525 g kg-1 imazapyr, and 175 g kg-1 imazapic). Two field experiments were conducted in the 2015-2016 crop season in two sites with different soil and weather characteristics located in the state of Paraná, Brazil. A completely randomized block design was used, with 11 treatments consisted of different rates of Soyvance®. Phytotoxicity, chlorophyll index, first pod height, plant height, number of pods per plant, 100-seed weight, and grain yield were evaluated. The use of high rates of the herbicide decreased the final height and grain yield of soybean plants in approximately 25% in both locations, but did not affect their 100-seed weight and chlorophyll index. The use of rates of the commercial product higher than that recommended by the manufacturer (100 g ha-1) may affect the agronomic performance of AHAS-transgene soybean plants. São Paulo State University (UNESP) School of Agricultural Sciences Federal University of Paraná (UFPR) Department of Agricultural Sciences, Palotina State University of Maringá (UEM) Program of Agricultural Science, Maringá São Paulo State University (UNESP) School of Agricultural Sciences

O presente trabalho tem como objetivo avaliar o desempenho da soja submetida a doses de glyphosate, bem como os efeitos de associações de produtos ao herbicida, visando o processo de reversão do efeito fitotóxico na soja RR2. O experimento foi conduzido entre novembro de 2015 e janeiro de 2016, em casa de vegetação situada na Universidade Federal do Paraná – Setor Palotina. A cultivar utilizada foi a Monsoy 6210 IPRO®, delineamento inteiramente casualizado com quatro repetições. As plantas foram submetidas a aplicação de glyphosate nas doses 0, 720, 1440, 2160 e 2880 g e.a. ha-1 e doses de glyphosate em associação com os produtos: regulador de crescimento vegetal (cinetina 0,09 g L-1, ácido giberélico 0,05 g L-1 e ácido 4-indol-3-butílico 0,05 g L-1) na dose 250ml ha-1, manganês (Mn na forma de um quelato de aminoácido, 62,5 g L-1) na dose de 1L, e o composto de aminoácidos (hidrolisado proteico, ácido fosfórico, hidróxido de potássio e água, 1L ha-1). A aplicação foi realizada no estágio V4 da cultura. Foi avaliado índice de clorofila das plantas, matéria seca de parte aérea e raiz, e nota visual de fitointoxicação, que foi determinada através da atribuição de notas que representavam a porcentagem de área foliar danificada. Os dados foram submetidos a análise de variância, e quando houve significância, foram submetidas ao teste de Tukey (p≤0,05) e análise de regressão para o fator dose. Observou-se que para cultivar adotada, nas condições deste experimento que o manganês e o biorregulador foram eficientes na avaliação de nota visual de fitointoxicação. Para as variáveis matéria seca de raiz e parte aérea das plantas, não foi observada diferença entre os manejos de reversão.

Made available in DSpace on 2020-12-12T02:29:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-07-01 Eucalyptus harvests generate residues that remain on the soil and affect the efficacy of preemergent herbicides in the following planting cycle. The objective of this work was to evaluate the dynamics of flumioxazin, sulfentrazone, and isoxaflutole herbicides applied on different amounts and compositions of eucalyptus harvest residues subjected to different rainfall depths; and evaluate the weed control effectiveness of these herbicides when applied under these conditions. A LC–MS/MS system was used for the evaluations and the results showed that a cumulative rainfall of 50 mm was sufficient for the maximum removal of herbicides from the eucalyptus residues, regardless of the residue composition. The amount of the flumioxazin, sulfentrazone, and isoxaflutole herbicides that reached the soil was lower in the treatment with the highest amount of eucalyptus harvest residue used (40 Mg ha−1). The greatest amount of herbicide reaching the soil was found with the use of 15 Mg ha−1 of residues without presence of bark. The highest amount of residue used (40 Mg ha−1) reduced the control of Brachiaria decumbens by sulfentrazone and isoxaflutole. The control of Commelina benghalensis was inefficient (> 80%) in the treatment with 15 Mg ha−1 of residues without barks, regardless of the herbicide. Sulfentrazone controlled Ipomoea grandifolia (> 90%) under the evaluated residue conditions. Spermacoce latifolia and Sida rhombifolia were controlled by all herbicides in the evaluated residue conditions. Isoxaflutole controlled Panicum maximum in all residue conditions. The choice between the herbicides depends on the residue condition, rainfall regime, and weed species to be controlled. School of Agriculture of the São Paulo State University (Unesp), Av. Universitária, 3780 - Altos do Paraíso, Fazenda Experimental Lageado School of Agriculture of the São Paulo State University (Unesp), Av. Universitária, 3780 - Altos do Paraíso, Fazenda Experimental Lageado

Made available in DSpace on 2020-12-12T02:47:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-07-01 Several maize hybrids that present the phosphinothricin acetyltransferase gene (pat) are available in the market. However, these hybrids have different resistance levels to glufosinate herbicides. The objective of the present work was to evaluate the resistance of maize hybrids containing the pat gene (as a selection marker) to glufosinate. Field experiments were conducted in two sites in the 2016/2017 crop season, using a randomized block design with a 2×7 factorial arrangement and four replications. The treatments consisted of two glufosinate rates (0 and 500 g ha-1) and seven maize hybrids, six containing the pat gene as a selection marker (Herculex®, Agrisure-TL®, Herculex Yieldgard®, Leptra®, Viptera-3®, and Power-Core®) and one without the pat gene (VT PRO®). Two field experiments were conducted in different sites. The analyzed variables were: ammonia accumulation, electron transport rate (ETR), percentage of injuries, 100-grain weight, and grain yield. The glufosinate-susceptible maize hybrid presented higher ammonia accumulations, lower ETR, and high percentage of injuries (100%), which caused total loss of grain production. Considering the evaluated glufosinate-resistant maize hybrids, Viptera-3 and Agrisure-TL presented the highest ammonia accumulations and percentages of injuries, and lower ETR than the other hybrids. The grain yield of glufosinate-resistant maize hybrids was not reduced due to the application of the 500 g ha-1 of glufosinate. Thus, glufosinate-resistant maize hybrids containing the pat gene are resistant to the application of 500 g ha-1 of glufosinate, and this practice can be recommended for maize crops. Department of Plant Breeding and Production São Paulo State University (UNESP) School of Agriculture Department of Plant Breeding and Production São Paulo State University (UNESP) School of Agriculture

Made available in DSpace on 2019-10-06T15:19:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-09-01 Susceptibility to chlorimuron varies according to soybean genotype. STS® (sulfonylurea-tolerant soybean) presents a high tolerance to some sulfonylureas; this feature is determined by semi-dominants alleles, Als1 and Als2. Experiments were conducted in the field for four seasons with two cultivars for season to evaluate the selectivity of chlorimuron rates in post-emergency (V4) of glyphosate-tolerant and sulfonylurea-tolerant soybean. Data analysis made it possible to infer that there was no significant effect on the productivity of the cultivars when they received application in post-emergency, of chlorimuron at the doses used (0, 15, 30, 45, 60, 75, and 90 g ai ha-1). The maximum recommended rate for non-STS cultivars of chlorimuron is 20 g ai ha-1, or 4.5 times less than the maximum rate employed in this study. The soybean cultivars CD 250 RR/STS, CD 236 RR/STS, CD 2630 RR/STS, and BMX Turbo RR/STS were tolerant to the application, in post-emergency (V4) of the herbicide chlorimuron, until the rate of 90 g ai ha-1. Department of Agronomic Sciences Federal University of Paraná (UFPR) Palotina Campus Department of Crop Science University of São Paulo (USP) “Luiz de Queiroz” College of Agriculture (ESALQ) Faculty of Agronomic Sciences São Paulo State University (UNESP) Faculty of Agronomic Sciences São Paulo State University (UNESP)

Made available in DSpace on 2019-10-06T15:52:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01. Added 1 bitstream(s) on 2021-07-15T14:35:37Z : No. of bitstreams: 1 S0100-83582019000100238.pdf: 317328 bytes, checksum: 17b818586ee9c7b39a6af91680f80e6a (MD5) Horseweed (Conyza spp.) is a weed with a considerable presence and frequency throughout Brazilian crops, as well as presenting difficult chemical control. The objective of this study was to evaluate the efficiency of herbicide management, through single and sequential applications, in controlling Conyza spp., at two development stages with 4 to 6 leaves (3 to 5 cm) and 20 leaves (15-20 cm). The analyzed variables were: control percentage (7, 14, 21, and 28 days after application), dry matter content (28 days after application) and regrowth percentage (21 days after application). Data were submitted to analysis of variance at 5% probability and when there was a difference, the means were submitted to the Scott-Knott test. For Conyza spp. plants with a height between 3 and 5 cm and 4 to 6 leaves, the best treatments were T4, T8, T9, T10, T11, T12, T13, and T14, presenting a control percentage above 90%, 7 days after application. For Conyzaspp. plants with a plant development of 15 cm in height and 15 to 20 leaves, the highest control percentages and lowest regrowth percentages were with treatments T9, T13, and T14. UNESP Botucatu Universidade Federal do Paraná UNESP Botucatu

Para alcancar altos rendimentos, e necessario um programa avancado de manejo de plantas daninhas. O milho com os genes cp4-epsps e pat e tolerante aos herbicidas glyphosate e amonio glufosinato, e tem sido uma ferramenta usada para o controle de plantas daninhas, porem ha uma demanda por novos estudos a este respeito, avaliando a sua resistencia, evitando-se perdas de rendimento. O objetivo deste estudo foi testar a seletividade do hibrido 2B810PW, que possui os genes cp4-epsps e pat , submetidos a aplicacoes de glyphosate (gly) e amonio glufosinato (glu), tanto isolados como em mistura, em duas doses, durante tres safras, e em dois municipios do estado do Parana. O delineamento experimental utilizado foi em blocos ao acaso com quatro repeticoes. Algumas variaveis mensuradas, como altura de plantas (AP) e os teores de clorofila, mostraram poucas diferencas entre as safras e locais, mas outras como porcentagem de germinacao das sementes (Germ) e produtividade, nao apresentaram diferenca (P ≤ 0,05). Isso demonstra que o hibrido e resistente aplicacao dos herbicidas amonio glufosinato e glyphosate, isolados ou em mistura, e essas moleculas podem fornecer mais opcoes de controle de plantas daninhas na cultura do milho contendo os genes cp4-epsps e pat .

With the possibility of using ammonium glufosinate in corn, studies on its association with other herbicides are essential. The aim of this study was to assess weed control and herbicide selectivity in association with ammonium glufosinate in corn containing the pat and cp4-epsps genes. The experiment was carried out under field conditions in two sites in a randomized block design with four replications. Treatments consisted of ammonium glufosinate, glyphosate, ammonium glufosinate + glyphosate, ammonium glufosinate + nicosulfuron, ammonium glufosinate + atrazine, ammonium glufosinate + tembotrione, ammonium glufosinate + mesotrione, ammonium glufosinate + carfentrazone ethyl, ammonium glufosinate + bentazon, ammonium glufosinate + 2,4-D, control without weeding, and hand-weeded control. Visual assessments were performed regarding damage, electron transport rate in photosystem II (ETR), ammonia quantification, height, and grain yield of corn plants, as well as weed control at both sites. The application of ammonium glufosinate and its associations did not provide a reduction in productivity when compared to the hand-weeded control. Some treatments presented higher levels of visual damage and ammonia accumulation, but without a yield reduction. Therefore, herbicide mixture with ammonium glufosinate may be an alternative to weed control without damaging corn crop, which presents in its genetic constitution the cp4-epsps and pat genes. RESUMO: Com a possibilidade do uso de amônio-glufosinate no milho, são fundamentais estudos com associações desse herbicida junto a outros. O objetivo do presente trabalho foi avaliar o controle de plantas daninhas e a seletividade de herbicidas em associação ao amônio-glufosinate em milho contendo os genes pat e cp4-epsps. O experimento foi realizado em campo em duas localidades, dispostos em blocos ao acaso com quatro repetições. Os tratamentos foram: amônio-glufosinate; glyphosate; amônio-glufosinate + glyphosate; amônio-glufosinate + nicosulfuron; amônio-glufosinate + atrazine; amônio-glufosinate + tembotrione; amônio-glufosinate + mesotrione; amônio-glufosinate + carfentrazone ethyl; amônio-glufosinate + bentazon; amônio-glufosinate + 2,4-D; e testemunha sem capina e testemunha capinada. Foram feitas realizadas avaliações visuais de injúria, fluxo de transporte de elétrons do fotossistema II (ETR), quantificação de amônia, altura e rendimento de grãos das plantas de milho, além de controle das plantas daninhas em ambos os locais. A adoção da aplicação de glufosinate e suas associações não proporcionou redução de produtividade quando comparada à testemunha capinada; alguns tratamentos apresentaram maiores níveis de injúria visual e acúmulo de amônia, porém sem redução de produtividade. Portanto, a mistura de herbicidas com o amônio-glufosinate pode ser uma alternativa para o controle de plantas daninhas, sem causar danos à cultura do milho, que apresenta na sua constituição genética os genes cp4-epsps e pat.

Control of Conyza spp. prior to soybean sowing has faced difficulties because of the resistance cases in Brazil, hence new herbicides as halauxifen-methyl + diclosulam are important to manage this specie. The objective of this research was to evaluate the effectiveness of the herbicide halauxifen-methyl + diclosulam applied at pre-planting of soybean. The experiments were set up in three locations in Paraná State, Brazil, in the 2015/2016 season. The herbicide halauxifen-methyl + diclosulam was associated with glyphosate and compared to other commercial herbicide to Conyza spp. control. The application occurred 15 days before soybean sowing, in plants of Conyza spp. with an average height of 20-35 cm in the three areas. None of the treatments promoted Conyza spp. control above 90%, when soybean was at the V1 stage; however, the findings showed that halauxifen-methyl + diclosulam promoted better control in comparison to the other treatments. The control reached >90% at V3 soybean development stage, in which treatments containing glyphosate + halauxifen-methyl + diclosulam were more effective than the other treatments. In addition, treatments with glyphosate + halauxifen-methyl + diclosulam decreased dry matter content of Conyza spp. between 87 and 93%, depending on the location, when compared to the control. The burndown treatment to Conyza spp. with glyphosate + halauxifen-methyl + diclosulam did not decrease soybean yield, and it was always higher than the untreated check. RESUMO: O controle de Conyza spp. antecedendo a semeadura da soja tem apresentado dificuldades no Brasil devido à presença de casos de resistência. Assim, novos herbicidas, como halauxifen-methyl + diclosulam, são importantes no manejo dessa espécie. O objetivo desta pesquisa foi avaliar a eficácia do herbicida halauxifen-methyl + diclosulam aplicado em dessecação pré-plantio da soja. Os experimentos foram instalados em três localidades no Estado do Paraná, Brasil, na safra de 2015/2016. O herbicida halauxifen-methyl + diclosulam foi associado ao glyphosate e comparado com outros herbicidas encontrados no mercado para o controle de buva; a aplicação ocorreu 15 dias antes da semeadura da soja, em plantas de Conyzaspp. com altura média de 20-35 cm, nas três áreas. Nenhum dos tratamentos promoveu controle de Conyzaspp., superior a 90%, quando a soja se encontrava no estádio V1; entretanto, os resultados demonstraram que halauxifen-methyl + diclosulam promoveu melhor controle em relação aos demais tratamentos. O controle melhorou (>90%) no estádio de desenvolvimento V3 da soja, no qual os tratamentos contendo glyphosate + halauxifen-methyl + diclosulam se mostraram superiores aos demais; além disso, os tratamentos com glyphosate + halauxifen-methyl + diclosulam diminuíram a matéria da massa seca de Conyza spp. entre 87 e 93%, dependendo da localização, quando comparados com o controle. A dessecação da buva com glyphosate + halauxifen-methyl + diclosulam não diminuiu a produtividade da soja, tendo sido esta sempre maior que a da testemunha não capinada.

Phosphinothricin acetyltransferase ( pat) gene confers resistance to glufosinate by transforming this herbicide into N-acetyl-l-glufosinate (NAG). The pat gene was inserted in six maize hybrids (Herculex, Agrisure TL, Herculex Yieldgard, Leptra, Viptera 3, Power Core) as a selectable marker, and its expression was evaluated by qPCR in comparison with the maize glufosinate-susceptible cultivar VTPRO. In addition, the levels of NAG, glufosinate degradation, ammonia accumulation, electron transport rate (ETR), visual injury, and biomass were also investigated. The VTPRO, Herculex, Agrisure, and Viptera showed lower pat gene expression, and consequently lower NAG contents and glufosinate degradation, as well as reduced ETR and biomass accumulation. In contrast, greater ammonia accumulation and higher visual injury were observed. The ranking of pat gene expression was LeptraPower CoreHerculex Yieldgard ≫ HerculexAgrisure TL = Viptera 3VTPRO. This gene expression was proportional to the glufosinate resistance level observed in each maize hybrid.

Made available in DSpace on 2019-10-03T18:19:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01. Added 1 bitstream(s) on 2019-10-09T18:33:21Z : No. of bitstreams: 1 S0100-83582018000100306.pdf: 1030366 bytes, checksum: 0a20f2f4f94286c88fdd366df1b1a081 (MD5) This study aimed at evaluating the agronomic performance of Intacta RR2 soybean submitted to the application of glyphosate doses in post-emergence. For this, two experiments were conducted in two locations (Palotina and Marechal Candido Rondon - Parana state). Applications were carried out with increasing rates of glyphosate (0, 720, 1,440, 2,160, 2,880, 3,600, 4,320 g a.e. ha(-1)), constituting seven treatments with an experimental design in randomized blocks with four replications, totaling 28 plots for each location. The cultivar used for both experiments was Monsoy 6210 Intacta RR2 IPRO (TM). The analyzed variables were phytotoxicity at 3, 7,14, 21 and 28 DAA, A-B and total chlorophyll index, final height, number of pods, 100-seed weight, and yield. A regression analysis was used. There was a positive behavior of the linear regression for phytotoxicity and a negative one for final height, number of pods, A-B and total chlorophyll index, and yield in the city of Palotina. In Marechal Candido Rondon, there were adjustments of the positive linear regressions for phytotoxicity, and negative linear regressions for chlorophyll index, final height, number of pods and yield. Results show that the glyphosate increase from the dose 1,440 g a.e. ha(-1) in the studied cultivar damaged the agronomic performance of the culture. UNESP, Botucatu, SP, Brazil Univ Fed Parana, Palotina, PR, Brazil UNESP, Botucatu, SP, Brazil

The effectiveness of a new product has a great importance to weed control, especially those that are difficult to control or resistant to, such as the sumatran fleabane (Conyza sumatrensis). The objective of this research was to evaluate the control of C. sumatrensis at different growth stages, using halauxifen-methyl in combination with other herbicides. The experimental design used was a randomized blocks in a 3x10 factorial scheme, with four replications. The plants of C. sumatrensis were evaluated at different growth: stage 1: plants with 8 leaves; Stage 2: plants with 19 leaves and stage 3: plants with 45 leaves fully expanded. The herbicides used were the association of glyphosate with the herbicides 2,4-D at 806, 943 and 1,209 g a.e. ha-1, halauxifen-methyl + diclosulam at 5.06 g a.e. ha-1 + 25.52 g a.i. ha-1 and 6.32 g a.e. ha-1 + 31.87 g a.i. ha-1, halauxifen-methyl + 2,4-D at 5.00 + 783 g a.e. ha-1 and 6,0 + 940 g a.e. ha-1 and halauxifen-methyl at 5.0 and 6.0 g a.e. ha-1 and untreated, totaling 10 treatments. The herbicides demonstrated satisfactory control of the plants in Stage 1 at 50 DAA, with the exception of the glyphosate + 2,4-D treatment at the lowest rate. However for Stages 2 and 3 the halauxifen-methyl + diclosulam in both rates, provided superior controls in relation to the other treatments. The control of sumatran fleabane was facilitated when their management occurs in the early stages of development, however independent of the development stage, the best controls obtained were with the treatment containing glyphosate + halauxifen-methyl + diclosulam at 1,440 g a.e. ha-1 + 6.32 g a.e. ha-1 + 31.87 g a.i. ha-1. Thus, combinations of herbicides containing halauxifen-methyl are another option to control C. sumatrensis in agricultural systems. RESUMO: A confirmação da efetividade de novos produtos é de grande importância para o controle de plantas daninhas, principalmente aquelas de difícil controle ou resistentes, como o caso da buva (Conyza sumatrensis). O objetivo deste trabalho foi avaliar o controle de C. sumatrensis em diferentes estádios de desenvolvimento, utilizando-se halauxifen-methyl em associação com outros princípios ativos de herbicidas. O delineamento experimental utilizado foi de blocos ao acaso, em esquema fatorial 3x10, com quatro repetições. As plantas de C. sumatrensis foram divididas em três estádios de desenvolvimento: estádio 1: plantas com 8 folhas, estádio 2: plantas com 19 folhas e estádio 3: plantas com 45 folhas totalmente expandidas. Os tratamentos consistiram da associação de glyphosate (1.440 g ha-1) com os herbicidas 2,4-D a 806, 943 e 1.209 g e.a. ha-1, halauxifen-methyl + diclosulam at 5,06 g e.a. ha-1 + 25,52 g i.a. ha-1 and 6,32 g e.a. ha-1 + 31,87 g i.a. ha-1, halauxifen-methyl + 2,4-D at 5,00 + 783 g e.a. ha-1 and 6,0 + 940 g e.a. ha-1 and halauxifen-methyl at 5.0 and 6.0 g e.a. ha-1, além de testemunha sem aplicação, totalizando 10 tratamentos. Os herbicidas apresentaram controle satisfatório das plantas de buva no estádio 1 aos 50 DAA, com exceção do tratamento glyphosate + 2,4-D, na dose mais baixa. Contudo, para os estádios 2 e 3 o halauxifen-methyl + diclosulam, em ambas as doses, proporcionou controles superiores em relação aos demais tratamentos. O controle de C. sumatrensis foi facilitado quando manejado em estádios iniciais de desenvolvimento; entretanto, independentemente do estádio de desenvolvimento, os melhores controles foram com o tratamento contendo glyphosate + halauxifen-methyl + diclosulam a 1.440 g e.a. ha-1 + 6.32 g e.a. ha-1 + 31.87 g i.a. ha-1. Assim, as associações de herbicidas contendo halauxifen-methyl são mais uma opção para o manejo de C. sumatrensis nos sistemas agrícolas.

Made available in DSpace on 2019-10-04T12:42:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-07-01. Added 1 bitstream(s) on 2021-07-15T15:04:58Z : No. of bitstreams: 1 S0104-77602018000300162.pdf: 1031369 bytes, checksum: c2d0028d11d2931b8803f6af7d1f78dc (MD5) Eucalyptus stands out in the Brazilian silvicultural sector as the most planted tree species for commercial purposes thus, practices that facilitate management and improve wood quality are increasingly required. Although artificial mechanical pruning has been used for this crop, the use of herbicides for pruning can be more practical, rapid and have lower costs. Thus, the objective of this work was to evaluate the use of glufosinate ammonium in the chemical pruning of eucalyptus plants. Eucalyptus seedlings were transplanted into 10-L pots filled with soil and substrate and subjected to the treatments (mechanical pruning, chemical pruning, and no pruning) 90 days after transplanting. Lateral branches were cut with pruning shears for the mechanical pruning. Glufosinate ammonium (500 g a.i. ha(-1)) was applied to the sides of the plants for the chemical pruning, simulating a fieldplanting row (3.5 x 2.0 meters), using a CO2-pressurized sprayer; the untreated branches were covered with plastic bags to avoid receiving the herbicide. The percentage of artificial pruning used was 60% of the vertical height of the eucalyptus plants. Glufosinate, glutamate, and ammonia contents, electron transport rate, percentage of pruning, plant height, number of leaves, and dry matter mass of the plants were evaluated. The application of glufosinate ammonium defoliate the treated branches and did not affect significantly the parts of the plants that did not receive the herbicide regarding the evaluated compounds, and growth of the plants, denoting that glufosinate ammonium can be used for chemical pruning of eucalyptus plants. Sao Paulo State Univ, Botucatu, SP, Brazil Bayer Environm Sci, Botucatu, SP, Brazil Sao Paulo State Univ, Botucatu, SP, Brazil

Made available in DSpace on 2018-12-11T16:51:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-04-01 Universidade Federal do Paraná For optimum yield, it is necessary to incorporate a good weed control into the system. This study aimed to determine the effects of a post-emergent application of different herbicides (individually and combined) on corn presenting cp4-epsps and pat genes. Field studies were conducted on the corn hybrid 2B810 with the cp4-epsps and pat genes in the agricultural years 2012/13 and 2013/14 and included 8 treatments with isolated and combined application of glyphosate, glufosinate-ammonium, and atrazine. The variables evaluated were chlorophyll type a and b, total chlorophyll index, stem diameter, height of the cob insertion, prolificacy index, first height, second height, yield, and volume of 100 grains. The combination of all three herbicides hindered the yield of corn cultures. This practice therefore requires caution when applied to weed management. The combination of two herbicides did not affect the final height or yield and may be a useful method of weed management in future. São Paulo State University (Unesp) School of Agriculture Federal University of Paraná - Agronomy Department Luiz de Queiroz College of Agriculture University of São Paulo São Paulo State University (Unesp) School of Agriculture

The long-term exploitation of natural resources by agricultural activities has resulted in the need for alternative measures to restore degraded soil. The cultivation of cover crops can generate great benefits for agricultural systems, enabling the exploitation of natural resources, including water, light and nutrients, as well as the recovery of degraded soils. This work aimed to assess the coverage rate, fresh mass and dry mass of cover crops from fall and winter as well as the floristic composition of the weeds. The work was conducted in field conditions in soil classified as eutroferric Red Oxisol in the region of the city of Palotina, Paraná State, Brazil, using a random block experimental design with four replications. The treatments consisted of seven cover cultures: wild radish, linseed, triticale, rye, rapeseed, crambe, oats and fallow. The species with the highest coverage rates and fresh mass and dry mass values were wild radish, rapeseed and crambe. In the floristic and phytosociological data, the species with the highest incidence were Amaranthus retroflexus, Commelina benghalensis L., Brachiaria plantaginea and Gnaphalium spicatum. RESUMO. A exploração dos recursos naturais, pelas atividades agrícolas ao longo do tempo resultou na necessidade de buscar medidas alternativas para recuperação do solo degradado. O cultivo de plantas de cobertura é uma alternativa que gera grandes benefícios aos sistemas agrícolas, viabilizando a exploração dos recursos naturais, água, luz e nutrientes e recuperação de solos degradados. O objetivo deste trabalho foi avaliar o percentual de taxa de cobertura, massa fresca e massa seca das culturas de cobertura de outono e inverno e a composição florística de plantas daninhas. O trabalho foi conduzido em condições de campo em solo classificado como Latossolo Vermelho eutroférrico, na região do município de Palotina, Estado do Paraná, Brasil. O delineamento experimental utilizado foi o de blocos ao acaso, com quatro repetições, os tratamentos foram constituidos por sete culturas de coberturas: nabo forrageiro, linhaça, triticale, centeio, canola, crambe, aveia; e área de pousio. As espécies que apresentaram os maiores valores de taxa de cobertura, massa fresca e massa seca foi o nabo forrageiro, canola e crambe. No levantamento florístico e fitossociológico, as espécies com maior incidência foram Amaranthus retroflexus, Commelina benghalensis L., Brachiaria plantaginea e Gnaphalium spicatum.

The soybean cultivation along the years has required big investments and high technological level to develop new and more productive cultivars. However, the advent of biotic stress, such as diseases, can lead to losses in yield. To attenuate this interference and obtain the expected yield, chemical products have been used to control these diseases. This technique has shown good efficiency in short-term, but can damage the environment and promote the appearance of resistant biotypes in the long-term. So, alternative methods of diseases control, such as pyroligneous extract and the fungus Pycnoporus sanguineus have been used in soybean and other cultures to control diseases without the prior negative aspects of chemical products. The aim of this study was to evaluate possible interferences of these treatments in the agronomic performance of soybean culture. The experiment was conducted in the 2012/2013 harvest, submitting two soybean cultivars to pyroligneous aqueous extract in the 0.6 and 1.3% concentrations and the fungus P. sanguineus extract in the 2.5 and 5% concentrations, thus comparing their results with a positive control and water control treatment. The results showed that the 2.5% fungus concentration statistically reduced the yield of the Turbo RR® BMX cultivar and the 5% fungus concentration reduced the grain mass of Vmax RR® NK 7059. The pyroligneous extracts reduced the number of pods of the Turbo RR® BMX cultivar and the height of Vmax RR® NK 7059, but did not affect the yield. In either cultivar, the plant growth regulator obtained the best results for all characteristics. Key words: pyroligneous, Pycnoporus sanguineus, plant growth regulator.

Um dos métodos muito utilizados para gerar incremento de produtividade na cultura do milho é a aplicação de nitrogênio; contendo no mercado uma série de fontes alternativas do elemento. Portanto, o presente trabalho teve como objetivo avaliar a aplicação de fontes e doses de nitrogênio em cultivo de milho, avaliando parâmetros vegetativos e produtivos. O experimento foi realizado à campo no município de Palotina, em delineamento experimental de blocos ao acaso com 4 repetições. Os tratamentos constituíram-se de um esquema fatorial 4x5, com quatro fontes de nitrogênios: Sulfato de Amônio (SA: 21% N), Ureia comum (UC: 46% N), Nitrato de Amônio (NA: 34% N) e Nitrogênio Formulado (NM: 44,6% N + 0, 4 % B + 0,15 % Cu); em cinco doses (0, 30, 60, 90 e 120 kg N ha-1). A aplicação ocorreu no estádio V5-V6. As variáveis mensuradas foram: altura de plantas no florescimento, diâmetro de colmo, altura de inserção de primeira espiga, índice de prolificidade, massa de 100 grãos e produtividade. As fontes não apresentaram efeito significativo para as variáveis analisadas, com exceção da variável produtividade, em que se destacaram as fontes NA e NM. As doses por sua vez apresentaram efeito significativo para altura de plantas, diâmetro de colmo, altura de inserção da primeira espiga e produtividade. A produtividade se adequou à função linear positiva com as doses de N para a fonte NM.

Made available in DSpace on 2018-11-26T16:05:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01. Added 1 bitstream(s) on 2021-07-15T14:31:39Z : No. of bitstreams: 1 S0100-83582018000100275.pdf: 753405 bytes, checksum: 5e4cd96c5a90b6deb2a82ebc3eef18e8 (MD5) The goal of this study was to compare the efficacy of different weed management through a burndown application followed by sequential applications of herbicides to control Conyza spp. Thus, four field experiments were conducted, two in the western region of Parana state (E1 and E2), one in Jatai, Goias state (E3) and another one in Ibiruba, Rio Grande do Sul state (E4). Conyza spp. in this area had a height ranging between 25 and 60 cm. Treatments were arranged in a randomized block design with four replications. The primary herbicide treatments were 2,4-D + glyphosate + diclosulam, chlorimuron-ethyl + glyphosate + 2,4-D, and four doses of diclosulam + halauxifen-methyl + glyphosate. These treatments were applied singly or in sequential applications, made 10 days before the application of ammonium glufosinate, paraquat or saflufenacil. In all experiments, results showed efficient (90%) control of treatments containing diclosulam + halauxifen-methyl in combination with glyphosate on day 35 DAA, regardless of sequential applications. Applications of 2,4-D + glyphosate + diclosulam or chlorimuron-ethyl + glyphosate + 2,4-D were not effective against Conyza spp. at E1 and E2 locations, possibly due to the greater weed size (50 to 60 cm) at these sites. However, the same treatments were effective at E3 and E4 locations, where weeds were smaller. Diclosulam + halauxifen-methyl + glyphosate associated with ammonium glufosinate, paraquat or saflufenacil in sequential applications, proved to be an important tool to manage Conyza spp. at different growth stages. Dow AgroSci Ind Ltda, Sao Paulo, SP, Brazil Univ Estadual Paulista, Botucatu, SP, Brazil Univ Estadual Paulista, Botucatu, SP, Brazil

The Roundup Ready (RR) soybean was developed for weed control with the use of glyphosate. Some herbicide combinations with glyphosate has been used in weed control and some effects of this practice may be undesirable in the agronomic performance of RR soybean. The present study evaluated the agronomic performance of RR2 intact soybean applied with associations between herbicides and glyphosate at post-emergence, in two experiments conducted in two municipalities in the state of Paraná, Palotina and Marechal Cândido Rondon. This experiment consisted of seven treatments in a randomized block design with four replications, totaling 28 plots for each municipality. The cultivar used in both experiments was Monsoy 6210 Intact RR2 IPROTM. The variables analyzed were: phytotoxicity at 3, 7, 14, 21 and 28 days after application, chlorophyll A, B and total chlorophyll, final height, number of pods, 100 seed weight and yield. Data were analyzed by analysis of variance and Tukey’s test at 5%. There were differences between treatments for phytotoxicity in both locations and differences in yield (Palotina) and final height (Marechal Cândido Rondon). From the data it is understood that some associations of certain herbicides such as lactofen, chlorimuron-ethyl in the glyphosate can potentiating effect cause phytotoxicity and even reduction in productivity. RESUMO: A soja Roundup Ready (RR) foi desenvolvida para controle de plantas daninhas com a utilização do herbicida glyphosate. Algumas associações de herbicidas com o glyphosate vêm sendo usadas no controle de plantas daninhas, e alguns efeitos dessa prática podem ser indesejados no desempenho agronômico da soja RR. O presente trabalho objetivou avaliar o desempenho agronômico da soja intacta RR2 submetida a associações de herbicidas com o glyphosate, em pós-emergência. Para isso, foram realizados dois experimentos em duas localidades (Palotina - PR e Marechal Cândido Rondon - PR). Esses experimentos contiveram sete tratamentos com delineamento em blocos ao acaso com quatro repetições. O cultivar utilizado em ambas as localidades foi o Monsoy 6210 Intacta RR2 IPROTM. As variáveis analisadas foram fitotoxicidade aos 3, 7, 14, 21 e 28 dias após aplicação, índice de clorofila A, B e total, altura final, número de vagens, massa de 100 sementes e produtividade. Foi feita a análise de variância e utilizado o teste de média de Tukey a 5%. Houve diferença entre os tratamentos para fitotoxicidade em ambas as localidades e diferença na produtividade (Palotina) e altura final (Marechal Cândido Rondon). A partir dos resultados, conclui-se que algumas associações de determinados herbicidas, como chlorimuron-ethyl e lactofen, na presença do glyphosate podem provocar efeito potencializador de fitotoxicidade e até mesmo na redução na produtividade.

Made available in DSpace on 2022-04-28T19:06:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-03-01 Allelochemicals are important and innovative tools for weed control as they neither harm the environment nor increase weed management costs. The secondary metabolites can be extracted by water or soaking and later applied in soil or leaves. This study evaluated the leaf extracts of Cymbopogon citratus, affecting germination of Bidens pilosa and B. subalternans seeds. Two trials were conducted in germination chambers. The completely randomized design was employed in both trials with 5 replications. Trial one was arranged in a 2×3 double factorial design, with two periods of leave collection (morning and afternoon); and three extract preparations (aqueous extract by maceration, aqueous extract by infusion and control with distilled water). Trial two was set up in a 2×2×5 triple factorial design, with two extracts (aqueous extract by maceration, aqueous extract by infusion); two time of day collection (morning and afternoon) and five extracts concentrations (0; 25; 50; 75 and 100%). The means were compared by F and Tukey's test (p ≤ 0.05). To evaluate extracts concentrations a regression analysis was run. The results showed that the aqueous extract by maceration of C. citratus decreased germination and germination speed of Bidens pilosa and Bidens subalternans more than the aqueous extract by infusion, for both species. The concentrations interfered, inversely and proportionally, decreasing germination and germination speed. The germination of beggarticks was affected by the extracts of C. citratus, suggesting further studies for this plant. Faculty of Agronomic Sciences Sao Paulo State University Faculty of Agronomic Sciences Sao Paulo State University

O cártamo (Carthamus tinctorius L.) é uma planta oleaginosa que apresenta elevado potencial de cultivo no Brasil. O controle das plantas daninhas na cultura é essencial para proteger o seu potencial produtivo. O objetivo deste estudo foi avaliar a seletividade de herbicidas aplicados em pré-plantio incorporado (PPI), pré-plantio (PRÉ) e pós-emergência (PÓS) do cártamo. Ao todo, três estudos foram instalados em casa de vegetação, em delineamento inteiramente casualizado, com cinco repetições. Os herbicidas avaliados para aplicação em PPI (Experimento I) foram: diclosulam, metribuzin, pendimethalin e trifluralin; para aplicação em PRÉ (Experimento II) foram utilizados os herbicidas: 2,4-D, ametryn+clomazone, atrazine, carfentrazone, carfentrazone + sulfrentrazone, clomazone, diclosulam, flumioxazin, imazaqin, imazethapyr, isoxaflutole, lactofen, mesotrione, metribuzin, metsulfuron - methyl, pendimethalin, saflufenacil, s-metolachlor, sulfrentrazone e trifluralin e, para a aplicação em PÓS (Experimento III) foram avaliados: ametryn+clomazone, atrazine, bentazon, bentazon + imazamox, carfentrazone, chlorimuron, clethodim + fenoxaprop, clethodim, clodinafop, floroxypyr, fluazifop+fomesafen, fluazifopP, flumiclorac-pentyl, flumioxazin, fluroxipir, fomesafen, foramsulfuron + iodosulfuron, haloxyfop, imazethapyr, iodosulfuron, lactofen, mesotrione, nicosulfuron, tembotrione e tepraloxydim), comparados com a testemunha sem aplicação. A fitotoxicidade foi avaliada aos 7, 14, 21 e 28 dias após aplicação (DAA), usando a escala percentual de zero a 100, e a massa fresca e seca foram obtidas aos 35 DAA. Os dados foram submetidos a análise de variância e, as médias dos tratamentos foram comparadas pelo teste de Tukey (p≤0,05). O herbicida trifluralin apresenta seletividade a cultura do cártamo nas modalidades de PPI e PRÉ, enquanto que cletodim, fluazifop-p-butyl e haloxifope-p-metílico são seletivos para aplicação em PÓS.

The planting of RR2 Intacta soybeans by farmers has been expanding strongly. However, some visual injuries have been noted after glyphosate application. The aim of this study was to evaluate the influence of glyphosate application on chlorophyll, photosynthesis and water use of four Intacta RR2 soybean cultivars. The experiment was conducted in a greenhouse, in a randomized block design with a 3 × 4 factorial scheme, consisting of three glyphosate rates and four soybean cultivars. The glyphosate formula used was isopropylamine salt + potassium salt. The parameters analyzed were phytotoxicity at 7, 14, 21 and 28 days after application, and total chlorophyll index at 0, 3, 7, 14, 21, 28, 35, 42 and 49 days after application. Furthermore, 40 days after application, the net CO2 assimilation rate (A), transpiration rate (E), stomatal conductance (G), and internal CO2 concentration (Ci) were evaluated as well. The water-use efficiency (WUE) and carboxylation efficiency were calculated. The data were submitted to analysis of variance and compared by the Tukey’s test (p ≤ 0.05), followed by regression analysis. The phytotoxicity influence could be seen until 21 days after application, in which Monsoy 6210 IPRO cultivar was the most injured. The increasing doses promoted a reduction of the chlorophyll level up to 35 days after application in Monsoy 6410 IPRO. The cultivars tested here showed similar chlorophyll index values. On the 3rd, 7th and 14th DAA (Fig. 5a–c), there was a significant linear decline in the chlorophyll index with rising glyphosate dose for all four cultivars. The chlorophyll index cultivars were not influenced by the doses on the 42nd and 49th DAA. There was no difference in water use and carboxylation efficiency. The parameters A, E and A/Ci showed a positive correlation as the doses increased, while Ci declined, in both cultivars. The application of glyphosate on these soybean cultivars causes different injuries according to the sensitivity. In general, RR2 soybeans have the ability to recover from visual intoxication injuries and reestablish the normal chlorophyll production and photosynthetic parameters after glyphosate application.

Made available in DSpace on 2022-04-28T19:29:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01 One of the first transgenic traits that has been inserted into commercial crops and being widely used is tolerance to glyphosate herbicide. This technology has provided significant benefits and conveniences to farmers due to the efficacy of glyphosate. However, for a better weed control and prevention of weed resistant biotypes the use of two or more mechanisms is recommended practice. The combination of herbicides is the subject of several studies especially evaluating weed control, aside which the selectivity of the culture is equally important. In this context, this study aimed to evaluate the responses of transgenic corn (RR2) subjected to the application of different herbicides. For this purpose, an experiment was conducted with eight treatments using glyphosate, atrazine and nicosulfuron, sole or in combination along with a control treatment (without herbicide). The experiment was performed twice (first in Piracicaba - SP then Palotina - PR) in greenhouse with different corn hybrids. Several variables related to the performance were analysed such as height measurements, stem diameter, chlorophyll index, fresh and dry shoot, root dry mass. The results showed that nicosulfuron should be positioned cautiously in new RR2 corn hybrids, as it may damage the development of the plant. Federal University of Parana, Palotina Campus, Pioneer Street, 2153 - Garden Dallas State University of the Western of Paraná University Street, 2069 - University Garden State University of São Paulo Júlio de Mesquita Filho, Dr. José Barbosa de Barros Street, 1780 University of São Paulo/ Luiz de Queiroz College of Agriculture Padua Dias Avenue, 11 - Agronomy State University of São Paulo Júlio de Mesquita Filho, Dr. José Barbosa de Barros Street, 1780

Made available in DSpace on 2018-11-26T15:27:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-04-01. Added 1 bitstream(s) on 2019-10-09T18:24:55Z : No. of bitstreams: 1 S0100-83582015000200223.pdf: 1078076 bytes, checksum: 898347f7e2eb9f2ede74b892dd9e8f43 (MD5) Light, temperature and dormancy are factors that influence the germination of seeds and are strictly linked to the emergence of weeds. The objective of this work was to assess the germination of Sorghum arundinaceum and Sorghum halepense subjected to different conditions of temperature and luminosity, as well as assessing seed dormancy breaking mechanisms. For this, two experiments were conducted, both arranged in a completely randomized design. Experiment 1 was installed in a 2 x 5 double factorial design. The first factor was the absence or presence of light for 12 hours, and the other was composed of five constant temperatures: 15, 20, 30, 40 and 45 degrees C. In experiment 2, the efficiency of nine treatments used for breaking dormancy of seeds was assessed. The variables analyzed for both experiments were germination percentage and germination speed index (GSI). For the statistical analysis were performed an analysis of variance (ANOVA) and all the necessary consequences, as well as regression, when relevant. In experiment 1 for both species greater germination occurred in the presence of light. For S. arundinaceum the temperatures at which there was the highest percentage of germination were 33.13 and 31.24 degrees C for presence and absence of light respectively. As for S. halepense these temperatures were 31.98 and 29.75 degrees C for presence and absence of light respectively. As for the treatments for breaking dormancy, the mechanical scarification of seeds with sandpaper presented the highest germination and GSI. It is concluded that the Sorghum species studied are neutral photoblastic seeds and present mechanical type dormancy. Univ Fed Parana, Palotina, PR, Brazil Univ Estadual Paulista, Jaboticabal, SP, Brazil Escola Super Agr Luis Dequeiroz, Piracicaba, SP, Brazil Univ Estadual Paulista, Jaboticabal, SP, Brazil

The benefits of glyphosate tolerant crops technology are well-known, and its acceptance by farmers is undeniable. However, results of recent research indicate that, in some situations, glyphosate applied to herbicide-tolerant soybean crops may have phytotoxic effects affecting nutritional balance, photosynthesis and others biochemical process in plants. Despite the increasing information available on this subject, there are still scientific and technical issues that need to be clarified. Therefore, the present study aimed to assess the impact of applying different rates, management systems, and formulations of glyphosate to glyphosate-tolerant soybean trough different regions of Brazil in different environmental conditions. Two experiments were conducted over two crop seasons. A 2 × 2 × 5 (formulations × stage of application × doses) factorial design was used in each of them, for a total of 20 treatments with four replications. The study assessed a series of variables related to agronomic performance such as total chlorophyll and yield. The results suggest some problems associated with post-emergent use of glyphosate in tolerant soybean crop as 5% total yield reduction even without phytotoxicity symptoms dependent of season. There was not found any formulation interaction with yield decrease.

O objetivo do trabalho foi avaliar a seletividade dos herbicidas chlorimuron-ethyl, metsulfuron-methyl e nicosulfuron, aplicados em soja RR/STS. O experimento I constituiu-se da aplicação de doses (0, 15, 30, 45 e 60 g i. a. ha-1) de chlorimuron-ethyl. Para o experimento II foram aplicadas doses (0; 1,8; 3,6; 5,4 e 7,2 g i. a. ha-1) de metsulfuron-methyl. Para o experimento III foram aplicadas doses (0, 50, 100, 150 e 200 g i. a. ha-1) de nicosulfuron. Foi empregado delineamento experimental em blocos casualizados, com quatro repetições. Foram avaliadas: altura de plantas, número de vagens por planta, clorofila A, B e total, condutividade, vigor e germinação das sementes, produtividade e massa de mil sementes. Os dados foram submetidos à análise de regressão. De maneira geral, as variáveis analisadas não sofreram influência pela aplicação dos herbicidas. O cultivar de soja CD 250 RR/STS apresentou-se tolerante aos herbicidas chlorimuron-ethyl, metsulfuron-methyl e nicosulfuron.

O capim-amargoso é uma planta de difícil controle devido as suas características vegetativas de sobrevivência e pela sua resistência ao glyphosate. O objetivo do presente trabalho foi avaliar a eficácia de diversos graminicidas no controle do capim-amargoso perenizado em pleno florescimento. Para isso foram instalados dois experimentos a campo, sendo que no experimento 1 foram testados 4 graminicidas associados ao glyphosate, em aplicação única no qual foi avaliado as porcentagens de controle aos 14 e 28 dias após a aplicação (DAA). Já no experimento 2 foram aplicados 17 tratamentos (aplicação A) e após 35 dias realizada a aplicação sequencial de clethodim + glyphosate (Aplicação B), nesse experimento foram avaliadas as porcentagens de controle aos 14, 28 e 35 DAA de A e B, assim como a massa seca das plantas de capim-amargoso após a última avaliação de controle. No experimento 1 não se obteve controle satisfatório das plantas de capim-amargoso perenizado com nenhum dos tratamentos utilizados. No experimento 2, os resultados antes da aplicação sequencial (B) não foram eficientes no controle do capim-amargoso, entretanto aos 35 dias após aplicação B, os tratamentos com as doses de haloxyfop-methyl a partir de 100 g i.a. ha-1 associado ao herbicida clethodim + glyphosate (Aplicação B) foram eficientes no seu controle com consequente diminuição da massa seca. Conclui-se que a aplicação única de graminicidas não foi eficaz no controle do capim-amargoso em pleno florescimento, sendo necessário a aplicação sequencial (A + B) para promover o controle adequado.

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.

O manejo de plantas daninhas na cultura da soja destaca-se como importante ferramenta para assegurar seu alto potencial produtivo. O advento do plantio direto aumentou a importância do manejo realizado na entressafra e pré-semeadura da soja visando evitar a interferência das plantas daninhas no período inicial do cultivo. A pesquisa foi realizada com o objetivo de avaliar o controle de plantas daninhas e o desempenho agronômico da soja convencional com o uso de diferentes herbicidas dessecantes. O experimento foi realizado no delineamento de blocos casualizados, com quatro repetições. Os tratamentos foram arranjados no esquema fatorial 4x3, sendo o primeiro fator constituído dos herbicidas aplicados glyphosate - sal isopropilamida; glyphosate – sal de potássio; glyphosate – sal isopropilamida + 2,4-D; e paraquat + diuron e o segundo fator das épocas de aplicação (13 e 7 dias antes da semeadura - DAS; e 1 dia depois da semeadura - DDS). Avaliou-se o porcentual de controle de plantas daninhas, estande, emergência de plântulas, altura de plantas, número de vagens, massa de cem sementes e produtividade. A dessecação de manejo somente com glyphosate próximo a semeadura ocasionou decréscimo no percentual de controle de plantas daninhas, já uso de glyphosate + 2,4-D ocasionaram diminuição no crescimento inicial do cultivo devido à proximidade com a semeadura, aplicação de paraquat+diuron próximo a época se semeadura causou menor inserção de primeira vagem na cultura. Não houve diferenças significativas entre os tratamentos para componentes de produção da soja, nestas condições experimentais.

Este trabalho teve por objetivo conhecer, apresentar e analisar métodos de avaliação da composição florística e fitossociológica de plantas daninhas das principais culturas agrícolas, baseando-se em dados bibliográficos de diversos autores, dentro da literatura pertinente. Além dos cálculos específicos, como densidade e frequência, outros métodos de análise fitossociológica foram considerados quando utilizados nos levantamentos sobre a ocorrência de plantas daninhas de interesse econômico na literatura e também a variabilidade de métodos que podem ser utilizados para a condução do trabalho a campo do manejo de plantas daninhas. É recomendável que o trabalho de identificação de plantas daninhas seja feito após a colheita, onde a infestação é maior e a riqueza é considerável, outrora, a identificação de plantas muda de acordo com a cultura implantada seja perene ou anual. Várias outras cultivares podem ser avaliadas em períodos diferentes do recomendado como, por exemplo, o feijão-caupi, avaliado na fase vegetativa, e o guaraná, avaliado por idade das plantas. Os métodos de avaliação variam muito de autor para autor, o que torna difícil a escolha e padronização de um método para a avaliação florística e fitossociológica das plantas invasoras, dentro de um contexto do MIPD (manejo integrado de plantas daninhas) e na geração de resultados científicos. Tal retrato caracteriza a diversidade e complexidade dos agroecossitemas, dentro do contexto dos sistemas produtivos, e aponta para a necessidade de mais estudos. Floristic and Phy Tosociological Survey of Weeds: A Review of Methods Employed ABSTRACT: Current survey aims at knowing, presenting and analyzing the evaluation methods of the floristic and phytosociological composition of weeds from the main agricultural environment. It is based on bibliographical data from several authors within the extant literature. Besides specific methods, such as density and frequency, other phytosociological methods were investigated when used in the survey on the occurrence of economically interesting weeds mentioned in the literature and also in the variability of methods that may be employed on the field for weed management. It should be recommended that weed identification may be done after harvest since during this period infestation is highest and richness abounds. Plant identification changes according to perennial or annual culture. Several cultivars should be evaluated during different periods than those recommended, such as the caupi-beans, evaluated during the vegetative phase, and guaraná, evaluated by the plant´s age. Evaluation method vary according to authors and it is rather difficult to select and standardize a method for the floristic and phytosociological evaluation of invading plants within the integrated management of weeds, and in the production of scientific results. The above characterizes the diversity and complexity of agroecosystems within the context of production systems. Further studies are required. KEYWORDS: Floristics; Methods; Weeds; Variability.

A canola vem se destacando como ótima opção de cultura de inverno e hoje ocupa a quarta colocação mundial entre as oleaginosas em produção. Uma das grandes dificuldades no cultivo da canola é a época de colheita, pois suas síliquas não amadurecem de forma uniforme. Uma técnica que pode ser usada para favorecer a colheita é o uso de dessecantes. Com isso, o presente trabalho teve como objetivo avaliar o efeito da dessecação, em diferentes maturações das síliquas na cultura da canola. O trabalho foi realizado a campo no município de Terra Roxa - PR, utilizando-se o delineamento experimental de blocos ao acaso com quatro repetições. Os tratamentos foram constituídos da aplicação de paraquat (2,5 L ha-1 de Gramoxone 200®), pulverizados em épocas distintas do desenvolvimento da canola, a partir de três porcentagens de síliquas maduras, 30, 45 e 75% (avaliação visual), mais uma testemunha sem aplicação de herbicidas dessecantes. Não houve diferença significativa para produtividade e massa de mil sementes. Para o fator umidade das sementes ocorreu diferença significativa, com 75% de síliquas maduras ocorrendo nas menores umidades.

O manejo das espécies de cobertura pode ser realizado por métodos mecânicos ou químicos. No método químico são utilizados herbicidas não seletivos principalmente do grupo do glyphosate. O objetivo do presente trabalho foi avaliar a fitotoxicidade e a eficiência agronômica de duas formulações com princípio ativo glyphosate na dessecação em espécies de cobertura do solo. O presente trabalho foi conduzido no campo no município de Marechal Cândido Rondon/PR. O delineamento experimental foi de blocos ao acaso com quatro repetições com esquema fatorial de 2x5 (formulações x espécies), no qual as espécies constituíram-se de aveia-branca, aveia-preta, azevém, ervilhaca e nabo-forrageiro, dessecados por dois herbicidas: Zapp QI® (ZQ) e Glyphosate 480 Agripec® (GA). Foram avaliados fitotoxicidade e eficiência agronômica das espécies de cobertura. Zapp Qi® proporcionou maior fitotoxicidade e eficiência agronômica nas espécies de cobertura em relação ao Glyphosate 480 Agripec®. O Zapp Qi® aos 32 dias após a dessecação apresentou os maiores valores de eficiência agronômica. A única espécie que apresentou 100% de eficiência agronômica foi o nabo-forrageiro.

Some desiccation techniques for harvesting wheat may affect seed quality. The objective of this study was to evaluate the effect of different desiccant herbicides applied to the wheat crop and their effects on the production and seed quality. The experiment was conducted with cultivar COODETEC 150 (CD 150) in two sites in Palotina (Paraná state, Brazil) with a randomized block design consisting of 7 treatments (desiccation herbicides) and 4 replications. Desiccation was realized when 50% of the plants were in stage 80 with seeds in powdery or mass consistency. The variables analyzed were percentage of moisture content after harvest, Yield, hectoliter weight, mass of 100 seeds, vigor, germination, fresh mass of seedlings, dry mass of seedlings and root length. The herbicides carfentrazone-ethyl and clethodim were the ones that promoted greatest reduction in vigor. The herbicide paraquat caused reduction in seedling length. There was a reduction in the mass of 100 seeds for glufosinate-ammonium, clethodim, diquat and carfentrazone-ethyl. Glufosinate-ammonium, paraquat, glyphosate, clethodim and diquat caused reduction in yield. Desiccation of Cultivar CD 150 at stage 80 is not recommended, since plant Yield and physiological seed parameters were adversely affected by herbicides. Resumo: Algumas técnicas de manejo da cultura do trigo, como a dessecação pré-colheita podem afetar a produtividade e a qualidade fisiológica das sementes. O objetivo deste estudo foi avaliar o efeito de diferentes herbicidas dessecantes aplicados na cultura do trigo e seus efeitos sobre a produtividade e a qualidade das sementes. O experimento foi conduzido com a cultivar COODETEC 150 (CD 150), em dois ambientes de produção localizados no Município de Palotina - PR, sob o delineamento experimental de blocos casualisados, constituído de 7 tratamentos (herbicidas na dessecação) com 4 repetições. A dessecação foi realizada quando 50% das plantas apresentavam-se no estádio 80 com as sementes de consistência farinácea ou de massa. As variáveis analisadas foram umidade após a colheita, produtividade de sementes, peso hectolitro, massa de 100 sementes, germinação e vigor. Os herbicidas carfentrazone-ethyl e clethodim reduziram o vigor das sementes produzidas, e o herbicida paraquat reduziu o comprimento de plântulas. Ocorreu redução na massa de 100 sementes para o amônio - glufosinate, clethodim, diquat e carfentrazone-ethyl. O amônio - glufosinate, paraquat, glyphosate, clethodim e diquat reduziram a produtividade. A dessecação de plantas da cultivar CD 150 no estádio 80 não é recomendada, em decorrências dos efeitos negativos dos herbicidas nos parâmetros produtivos e fisiológicos das sementes de trigo.

Recent studies indicate that glyphosate applied in post-emergence in RR soybean can eventually cause phytotoxic effects. However, there are many questions that need to be clarified in the scientific and technical contexts, involving the issue of RR soybeans regarding the use of glyphosate. This study has assessed the impact of the application of different doses and formulations of glyphosate in the reproductive period of RR soybean (R1 stage). For that purpose, an experiment in the field was conducted in two harvests (2011/12 and 2012/13), in which a 2 x 5 factorial design was used (formulations versus doses) totaling 10 treatments. In these two experiments the variables related to agronomic performance were: phytotoxicity (7, 14, 21 and 28 days after application), plant height, number of pods per plant, yield and weight of 100 grains (end of soy cycle). The results obtained allowed characterizing phytotoxicity and damages to the height and yield in RR soybean, with increasing rates of glyphosate applied in the reproductive period. Resultados de pesquisas recentes indicam que o glyphosate aplicado em pós-emergência na soja RR pode, em algumas situações, gerar efeitos fitotóxicos. Entretanto, persistem muitas dúvidas que precisam ser melhor elucidadas no âmbito científico e técnico, envolvendo a questão da soja transgênica (RR), sobre aplicação de glyphosate. Desse modo, o presente trabalho teve por objetivo avaliar o impacto da aplicação de diferentes doses e formulações de glyphosate, no período reprodutivo da soja RR (estádio R1). Para isso, foi conduzido um experimento no campo, por duas safras (2011/12 e 2012/13), em que foi utilizado arranjo fatorial 2 x 5 (formulações x doses), totalizando 10 tratamentos. Nesses dois experimentos, as variáveis relacionadas ao desempenho agronômico foram: fitointoxicação (7, 14, 21 e 28 dias após a aplicação), altura de plantas, número de vagens por planta, produtividade e massa de 100 grãos (final do ciclo da cultura). Os resultados alcançados caracterizaram progressiva fitointoxicação e danos à altura e produtividade da soja RR, com o incremento das doses de glyphosate aplicadas no período reprodutivo.