RESUMO

Hyptis colombiana (Lamiaceae family), a species also treated as Cantinoa colombiana in a recently segregated genus from Hyptis, is a perennial herb or subshrub native to the Andes of northern South America. H. colombiana leaves are commonly used in traditional medicine to treat respiratory and digestive illnesses. In this study, H. colombiana plants at different phenological stages (vegetative, flowering, and post-flowering) were harvested to obtain essential oils (EOs) and extracts (from fresh plant materials or post-distillation waste) whose chemical compositions and antioxidant activities were determined. H. colombiana EOs distilled by microwave-assisted hydrodistillation were analyzed by GC/MS/FID, and hydroalcoholic extracts obtained from fresh plant materials or post-distillation waste were analyzed by UHPLC-ESI+/--Orbitrap-MS. The antioxidant activity was evaluated by the ABTS+• and ORAC assays. The principal compounds found in EOs were sesquiterpene hydrocarbons (65%); specifically, (E)-ß-caryophyllene and germacrene D. Pyranone, rosmarinic acid, rutin, and p-hydroxybenzoic acid were the main constituents in H. colombiana extracts. After analyzing the chemical composition and antioxidant activity (ORAC) of EOs and hydroethanolic extracts from flowering H. colombiana plants, minimal variations were found. It is advisable to harvest H. colombiana plants during their flowering stage to acquire EOs and extracts that can be utilized in the agro-industry of EOs and their natural derivatives.

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RESUMO

This study checked the severity and incubation period of isolates of Coryneporacassiicola (C.c) in soybean cultivars, as well verified whether the position of leaflets influences the susceptibility of the plant to target spot. The experiment was conducted in randomized block with 8 isolates of C.c and 8 soybean cultivars factorial scheme, with five repetitions each block. The plants were inoculated with suspension from 2x104 conidia mL-1. The number of lesions per leaf and the incubation period (IP) were evaluated. The ISO 4S isolate caused greater number of lesions in plants. BMX Potência RR, BMX Força RR, and NA 5909 RG had the lowest occurrence of lesions, while the cultivar BMX Elite IPRO showed the highest number of lesions. More lesions were detected in the lower leaf compared to the upper leaf of the plants. The longest IP was observed for ISO 4S in both leaflets, while the lowest IP for ISO 1A, 3A and 2A in the lower leaf, and for ISO 11S and 1S in the median leaf. For cultivars, significant difference in IP was observed only in the lower leaf, with the longest and shortest IP detected for BMX Elite IPRO and BRS 284, respectively. In general, the upper leaf of the plants presented the shortest IP while the lower leaf had the longest IP.

Este estudo teve como objetivo determinar o número de lesões e período de incubação de isolados de Corynespora cassiicola (C.c) em cultivares de soja, bem como verificar a influência da posição dos trifólios quanto a suscetibilidade a mancha alvo. O delineamento experimental foi de bloco causalizado em arranjo fatorial, oito isolados de C.c e oito cultivares de soja, com cinco repetições em cada bloco. As plantas foram inoculadas com suspensão de 2x104 conídio mL-1. Foram avaliados o número de lesões por folha e o período de incubação (IP). O isolado ISO 4S proporcionou maior número de lesões nas plantas. BMX Potência RR, BMX Força RR e NA 5909 RG apresentaram a menor ocorrência de lesões, enquanto a cultivar BMX Elite IPRO apresentou o maior número de lesões. Maior quantidade de lesões foram detectadas no trifólio inferior em comparação com o trifólio superior das plantas. O IP mais longo foi observado para ISO 4S em ambos os trifólios, enquanto o IP mais curto para ISO 1A, 3A e 2A no trifólio inferior, e para ISO 11S e 1S, trifólio mediano. Para as cultivares, observou-se diferença significativa no IP apenas no trifólio inferior, sendo o maior e menor IP constatados para BMX Elite IPRO e BRS 284, respectivamente. De modo geral, o trifólio superior das plantas demostrou o menor IP, enquanto o trifólio inferior o maior IP.

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RESUMO

Extreme climatic events are considered one of the main consequences of climate change. In the Pampas region, Argentina, an intensification of rainfall is expected during the periods of maximum agrochemical application. This study assesses the main factors determining the zooplankton community attributes in three streams belonging to the agricultural Pampas region, Argentina, and the effect of rainfall and seasonal crop practices on the zooplankton community composition. Sampling campaigns were performed before and after three rainfall events during two seasonal crop practices: (1) soybean chemical fallow-sowing and corn vegetative growth-flowering, (2) soybean vegetative growth-grain filling and corn sowing. The runoff in agricultural areas affected the zooplankton community attributes and composition. The biological oxygen demand, turbidity, and conductivity were the main water quality variables affecting the zooplankton community attributes. The increase of these variables after rainfall or during pre-emergence crop practices favoured the zooplankton groups most tolerant to eutrophication such as Bdelloidea, Chydoridae, Moinidae, and Sididae. Factors such as rainfall and seasonal crop practices must be considered in environmental monitoring design.

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RESUMO

An increase in the spatial variability of rainfall is expected due to climate change. This implies increasing rainfall rates during spring and summer in the Pampas region, Argentina, period of maximum application of agrochemicals, which might cause an increase in pesticides and nutrients carried to surface water systems, as runoff by rainfall is one of the main pathways for diffuse pollution. The crops phenological stage can also affect pesticide and nutrient runoff since the applied agrochemicals and soil cover differ in each stage. In this study, we assessed the influence of rainfall and seasonal crop practices on water quality (nutrient and pesticide concentrations) in three streams in the Pampas region, Argentina. Five sampling campaigns were performed before and after three rainfall events during two different seasons of crop practices (SCP1, SCP2) and the physicochemical characteristics of the stream and runoff water were analyzed. The pesticide concentrations in the streams presented a general increase immediately after the rainfall event. Water quality was also affected, as an increase in ammonium, soluble reactive phosphorus (SRP), biological oxygen demand (BOD), and turbidity was observed. The crops phenological stage influenced pesticide and nutrient types and concentrations detected in the streams. During SCP1, mainly characterized by chemical fallow and sowing of soybean and vegetative growth and flowering of corn, ammonium, SRP, BOD, turbidity, and some pesticides, such as metolachlor, showed significantly higher results than those found in SCP2 (grain filling and vegetative growth of soybean and corn sowing). The pesticide concentrations detected in runoff water depended mostly on the pesticide solubility, the lateral slope of the streams, and the percentage of woody riparian vegetation cover. The results obtained show the relevance of assessing the influence of rainfall and crops phenological stages on the dynamics of surface water and on pesticide and nutrient runoff for environmental monitoring.

RESUMO

The objective of this study was to evaluate the production and physical composition of three maize hybrids (Zea mays, L.) for silage production at six maturity stages. The hybrids evaluated were Maximus VIP3, Defender VIP and Feroz VIP. The experiment was conducted in a completely randomized block design with four replicates. The mean plant heights observed at harvest time (2.33 m, 2.45 m and 2.40m) demonstrated that all materials were medium-sized hybrids. A positive correlation was observed between plant height and height of the ear insertion, varying from 0.86 for the Feroz VIP hybrid to 0.88 for the Maximus VIP3 hybrid, but these two variants had no correlation with the productivity data. There was a significant difference for the production of fresh biomass at the R1, R2 and R5 stages, with Maximus VIP3 obtaining the highest yields. The proportion of grains in the physical composition of plant varied between hybrids, where Maximus VIP3 and Defender VIP (482.2 and 461.7 g kg-¹, respectively) were superior to Feroz VIP (429.7 g kg-¹). With the advancement of maturity, there was a decreasing linear behavior for stem and leaf participation, with reductions of 3.8 g kg-¹ and 4.5 gkg-¹, respectively, per day (R2 = 0.79 and 0.80, respectively), quadratic behavior for bracts and corncob and a linear increase in grain participation in the plant structure, with an increase of 7.7 g kg-¹ per day (R2 = 0.88). In general, the three hybrids present good characteristics for silage production and permit harvesting in the hard grain stage, allowing the addition of starch in relation to the farinaceous grain stage.(AU)

O objetivo do trabalho foi avaliar a produção e a composição física de três híbridos de milho (Zea mays, L.) para produção de silagem, em seis estádios de maturidade. Os híbridos avaliados foram o MaximusVIP3, Defender VIP e Feroz VIP. O experimento foi conduzido em delineamento de blocos inteiramente casualizados com quatro repetições e três tratamentos. A média de altura de planta observada no momento da colheita (2,33m, 2,45m e 2,40m, respectivamente) classifica todos os materiais como híbridos de porte médio. Foi observado correlação positiva, variando de 0,86 para o híbrido Feroz VIP a0,88 para o híbrido Maximus VIP3, entre a altura de planta e altura de inserção da espiga, porém, essas duas varáveis não tiveram correlação com os dados de produtividade. Houve diferença significativa para produção de biomassa fresca nos estádio R1, R2 e R5, tendo o Maximus VIP3 obtido as maiores produtividades. A proporção de grãos na composição física da planta variou entre os híbridos, onde o Maximus VIP3 e o Defender VIP (482,2 e 461,7 g kg-¹) foram superiores ao Feroz VIP (429,7 g kg-¹).Com o avanço da maturidade notou-se comportamento linear decrescente para participação de colmo e folha, com redução de 03,8 g kg-¹ e 04,5 g kg-¹ (R2=0,79 e 0,8; respectivamente) ao dia, quadrático para brácteas e sabugo, e linear crescente para participação de grãos na estrutura da planta, com aumento de 7,7 g kg-¹ ao dia (R2=0,88). De forma geral, os três híbridos apresentam boas características para produção de silagem e permitem a colheita em estádio de grão duro, possibilitando acréscimo de grãos em relação ao estádio de grão farináceo.(AU)

Assuntos

RESUMO

The objective of this study was to evaluate the production and physical composition of three maize hybrids (Zea mays, L.) for silage production at six maturity stages. The hybrids evaluated were Maximus VIP3, Defender VIP and Feroz VIP. The experiment was conducted in a completely randomized block design with four replicates. The mean plant heights observed at harvest time (2.33 m, 2.45 m and 2.40m) demonstrated that all materials were medium-sized hybrids. A positive correlation was observed between plant height and height of the ear insertion, varying from 0.86 for the Feroz VIP hybrid to 0.88 for the Maximus VIP3 hybrid, but these two variants had no correlation with the productivity data. There was a significant difference for the production of fresh biomass at the R1, R2 and R5 stages, with Maximus VIP3 obtaining the highest yields. The proportion of grains in the physical composition of plant varied between hybrids, where Maximus VIP3 and Defender VIP (482.2 and 461.7 g kg-¹, respectively) were superior to Feroz VIP (429.7 g kg-¹). With the advancement of maturity, there was a decreasing linear behavior for stem and leaf participation, with reductions of 3.8 g kg-¹ and 4.5 gkg-¹, respectively, per day (R2 = 0.79 and 0.80, respectively), quadratic behavior for bracts and corncob and a linear increase in grain participation in the plant structure, with an increase of 7.7 g kg-¹ per day (R2 = 0.88). In general, the three hybrids present good characteristics for silage production and permit harvesting in the hard grain stage, allowing the addition of starch in relation to the farinaceous grain stage.

O objetivo do trabalho foi avaliar a produção e a composição física de três híbridos de milho (Zea mays, L.) para produção de silagem, em seis estádios de maturidade. Os híbridos avaliados foram o MaximusVIP3, Defender VIP e Feroz VIP. O experimento foi conduzido em delineamento de blocos inteiramente casualizados com quatro repetições e três tratamentos. A média de altura de planta observada no momento da colheita (2,33m, 2,45m e 2,40m, respectivamente) classifica todos os materiais como híbridos de porte médio. Foi observado correlação positiva, variando de 0,86 para o híbrido Feroz VIP a0,88 para o híbrido Maximus VIP3, entre a altura de planta e altura de inserção da espiga, porém, essas duas varáveis não tiveram correlação com os dados de produtividade. Houve diferença significativa para produção de biomassa fresca nos estádio R1, R2 e R5, tendo o Maximus VIP3 obtido as maiores produtividades. A proporção de grãos na composição física da planta variou entre os híbridos, onde o Maximus VIP3 e o Defender VIP (482,2 e 461,7 g kg-¹) foram superiores ao Feroz VIP (429,7 g kg-¹).Com o avanço da maturidade notou-se comportamento linear decrescente para participação de colmo e folha, com redução de 03,8 g kg-¹ e 04,5 g kg-¹ (R2=0,79 e 0,8; respectivamente) ao dia, quadrático para brácteas e sabugo, e linear crescente para participação de grãos na estrutura da planta, com aumento de 7,7 g kg-¹ ao dia (R2=0,88). De forma geral, os três híbridos apresentam boas características para produção de silagem e permitem a colheita em estádio de grão duro, possibilitando acréscimo de grãos em relação ao estádio de grão farináceo.

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RESUMO

The aim was to evaluate the productive quality and fermentative as like the nutritional parameters of winter grass silage in the vegetative and reproductive stages in two consecutive crop years. The experiment was carried out at Universidade Tecnológica Federal do Paraná, Campus Dois Vizinhos, Brazil, from April 2012 to December 2013. The experimental field had a 560 m2 area; it comprised 32 plots of 16 m2 each, with a space of 0.5 m between blocks. Four winter grass species were used, including Avena sativa L. ‘IPR 126’ (white oat), Avena strigosa Schreb. ‘IAPAR 61’ (lopsided oat), Lolium multiflorum Lam. ‘Barjumbo’ (ryegrass), and Secale cereale L. ‘Temprano’ (rye), being evaluated through silage making in two phenological stages, vegetative and reproductive. The experimental design was randomized block in a bifactorial scheme (cultivar and phenological phase of pasture). The experimental materials were ensiled in polyvinyl chloride (PVC) microsiles, with four replicates per treatment. Pre-drying and ensiling allowed the preservation of material quality. The highest yields of dry matter per hectare were obtained in the reproductive stage; however, the nutritive content at this stage was relatively lower when compared with vegetative. The rye presented relatively less variation of the nutritional composition between the studied phenological stages. The ash content of the forage influenced the pH of the silage, and the highest pH was verified at the vegetative stage. Even with pre-dehydration, the vegetative stage presented a greater loss of effluents than the reproductive stage.

O objetivo foi avaliar a qualidade produtiva, parâmetros fermentativos e nutricionais da silagem das gramíneas temperadas nos estágios vegetativo e reprodutivo em dois anos consecutivos de cultivo. O trabalho foi conduzido na Universidade Tecnológica Federal do Paraná, Campus Dois Vizinhos - PR de abril de 2012 a dezembro de 2013. A área experimental possuía 560 m², divididos em 32 parcelas de 16 m² cada, com 0,5 m de espaçamento entre blocos. As gramíneas avaliadas foram: Aveia Branca cv. IPR 126 (Avena sativa L.), Aveia Preta cv. IAPAR 61 (Avena strigosa Schreb.), Azevém cv. Barjumbo (Lolium multiflorum Lam.) e Centeio cv. Temprano (Secale cereale L.), através da confecção de silagem pré-secada em dois estádios: vegetativo e reprodutivo. O delineamento experimental utilizado foi blocos ao acaso em esquema fatorial, avaliando o fator cultivar e o fator estádio fenológico das gramíneas. Foram avaliadas a qualidade nutricional e parâmetros fermentativos da silagem, assim como seu respectivo estádio fenológico. As forrageiras foram ensiladas em microssilos experimentais de PVC, com 4 repetições por tratamento. A pré-secagem e a ensilagem possibilitaram a conservação e qualidade do material. As maiores produções de matéria seca por hectare foram obtidas na fase reprodutiva, no entanto, a composição nutricional nesta fase apresentou teores inferiores comparados ao da fase vegetativa. O centeio apresentou menor variação da composição nutricional entre os estádios fenológicos estudados. O conteúdo mineral da forrageira influencia no pH da silagem, sendo que pH mais elevado é verificado no estádio vegetativo. Mesmo com a pré-secagem, o estádio vegetativo apresenta maior perda por efluentes quando comparada ao estádio reprodutivo.

Assuntos

RESUMO

The aim was to evaluate the productive quality and fermentative as like the nutritional parameters of winter grass silage in the vegetative and reproductive stages in two consecutive crop years. The experiment was carried out at Universidade Tecnológica Federal do Paraná, Campus Dois Vizinhos, Brazil, from April 2012 to December 2013. The experimental field had a 560 m2 area; it comprised 32 plots of 16 m2 each, with a space of 0.5 m between blocks. Four winter grass species were used, including Avena sativa L. ‘IPR 126 (white oat), Avena strigosa Schreb. ‘IAPAR 61 (lopsided oat), Lolium multiflorum Lam. ‘Barjumbo (ryegrass), and Secale cereale L. ‘Temprano (rye), being evaluated through silage making in two phenological stages, vegetative and reproductive. The experimental design was randomized block in a bifactorial scheme (cultivar and phenological phase of pasture). The experimental materials were ensiled in polyvinyl chloride (PVC) microsiles, with four replicates per treatment. Pre-drying and ensiling allowed the preservation of material quality. The highest yields of dry matter per hectare were obtained in the reproductive stage; however, the nutritive content at this stage was relatively lower when compared with vegetative. The rye presented relatively less variation of the nutritional composition between the studied phenological stages. The ash content of the forage influenced the pH of the silage, and the highest pH was verified at the vegetative stage. Even with pre-dehydration, the vegetative stage presented a greater loss of effluents than the reproductive stage.(AU)

O objetivo foi avaliar a qualidade produtiva, parâmetros fermentativos e nutricionais da silagem das gramíneas temperadas nos estágios vegetativo e reprodutivo em dois anos consecutivos de cultivo. O trabalho foi conduzido na Universidade Tecnológica Federal do Paraná, Campus Dois Vizinhos - PR de abril de 2012 a dezembro de 2013. A área experimental possuía 560 m², divididos em 32 parcelas de 16 m² cada, com 0,5 m de espaçamento entre blocos. As gramíneas avaliadas foram: Aveia Branca cv. IPR 126 (Avena sativa L.), Aveia Preta cv. IAPAR 61 (Avena strigosa Schreb.), Azevém cv. Barjumbo (Lolium multiflorum Lam.) e Centeio cv. Temprano (Secale cereale L.), através da confecção de silagem pré-secada em dois estádios: vegetativo e reprodutivo. O delineamento experimental utilizado foi blocos ao acaso em esquema fatorial, avaliando o fator cultivar e o fator estádio fenológico das gramíneas. Foram avaliadas a qualidade nutricional e parâmetros fermentativos da silagem, assim como seu respectivo estádio fenológico. As forrageiras foram ensiladas em microssilos experimentais de PVC, com 4 repetições por tratamento. A pré-secagem e a ensilagem possibilitaram a conservação e qualidade do material. As maiores produções de matéria seca por hectare foram obtidas na fase reprodutiva, no entanto, a composição nutricional nesta fase apresentou teores inferiores comparados ao da fase vegetativa. O centeio apresentou menor variação da composição nutricional entre os estádios fenológicos estudados. O conteúdo mineral da forrageira influencia no pH da silagem, sendo que pH mais elevado é verificado no estádio vegetativo. Mesmo com a pré-secagem, o estádio vegetativo apresenta maior perda por efluentes quando comparada ao estádio reprodutivo.(AU)

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RESUMO

O objetivo do presente trabalho foi avaliar a produção de fitomassa fresca e de fitomassa seca, assim como a composição física e bromatológica do feno do trigo cultivar BRS Umbu sob efeitos de dois níveis de adubação nitrogenada (120kg ha-1 e 180kg ha-1) e dois estádios fenológicos de colheita (pré-florescimento e grão farináceo). O delineamento experimental foi blocos ao acaso, em esquema fatorial 2x2, composto por quatro tratamentos com quatro repetições. Não houve interação (P>0,05) entre os níveis de adubação nitrogenada e os estádios fenológicos de colheita para todas as variáveis. A produção de fitomassa seca (P<0,05) nos estádios de grão farináceo e pré-florescimento foi de 10.171 e 4.982kg ha-1, respectivamente. A maior dose de N incrementou a produção de fitomassa seca em 775kg ha-1. Houve aumento da participação de espigas com o avanço do ciclo, apresentando-se 43,0% e 16,2% nos estádios grão farináceo e pré-florescimento, respectivamente. No estádio fenológico de pré-florescimento, a participação de folha verde foi superior (37,1% contra 9,8% da MS total). O feno colhido em estádio de grão farináceo apresentou menores teores de proteína bruta e fibra em detergente neutro. Os fenos produzidos apresentaram características distintas, o que permite seu uso em diferentes estratégias de alimentação de ruminantes.(AU)

The objective was to evaluate the production of the fresh and dry weight, physical and chemical composition of wheat hay, cv. BRS UMBU, under effects of two levels of nitrogen fertilization (120kg ha-1 and 180kg ha-1) and two harvest stages (pre-flowering and grain dough). The experimental design was randomized blocks in factorial 2X2, composed of four treatments with four replications. There was no interaction (p>0.05) between the levels of nitrogen fertilization and growth stages of harvest for all variables. The production of dry matter in the dough stage and pre-flowering were 10.171 and 4.982kg ha-1, respectively. The higher N rates increased the production of dry matter of 775kg ha-1. There was increased participation of spikes with the advancement of the cycle, presenting 43.0% and 16.2% in the dough stage and pre-flowering, respectively. In the growth stage of pre-flowering, the share of green leaf was higher (37.1% against 9.8% of the total MS). The hay harvested at dough stage had lower NDF and CP levels. Thus, each treatment presented favorable characteristics allowing its use in different strategies in ruminant nutrition.(AU)

Assuntos

RESUMO

O objetivo do presente trabalho foi avaliar a produção de fitomassa fresca e de fitomassa seca, assim como a composição física e bromatológica do feno do trigo cultivar BRS Umbu sob efeitos de dois níveis de adubação nitrogenada (120kg ha-1 e 180kg ha-1) e dois estádios fenológicos de colheita (pré-florescimento e grão farináceo). O delineamento experimental foi blocos ao acaso, em esquema fatorial 2x2, composto por quatro tratamentos com quatro repetições. Não houve interação (P>0,05) entre os níveis de adubação nitrogenada e os estádios fenológicos de colheita para todas as variáveis. A produção de fitomassa seca (P<0,05) nos estádios de grão farináceo e pré-florescimento foi de 10.171 e 4.982kg ha-1, respectivamente. A maior dose de N incrementou a produção de fitomassa seca em 775kg ha-1. Houve aumento da participação de espigas com o avanço do ciclo, apresentando-se 43,0% e 16,2% nos estádios grão farináceo e pré-florescimento, respectivamente. No estádio fenológico de pré-florescimento, a participação de folha verde foi superior (37,1% contra 9,8% da MS total). O feno colhido em estádio de grão farináceo apresentou menores teores de proteína bruta e fibra em detergente neutro. Os fenos produzidos apresentaram características distintas, o que permite seu uso em diferentes estratégias de alimentação de ruminantes.(AU)

The objective was to evaluate the production of the fresh and dry weight, physical and chemical composition of wheat hay, cv. BRS UMBU, under effects of two levels of nitrogen fertilization (120kg ha-1 and 180kg ha-1) and two harvest stages (pre-flowering and grain dough). The experimental design was randomized blocks in factorial 2X2, composed of four treatments with four replications. There was no interaction (p>0.05) between the levels of nitrogen fertilization and growth stages of harvest for all variables. The production of dry matter in the dough stage and pre-flowering were 10.171 and 4.982kg ha-1, respectively. The higher N rates increased the production of dry matter of 775kg ha-1. There was increased participation of spikes with the advancement of the cycle, presenting 43.0% and 16.2% in the dough stage and pre-flowering, respectively. In the growth stage of pre-flowering, the share of green leaf was higher (37.1% against 9.8% of the total MS). The hay harvested at dough stage had lower NDF and CP levels. Thus, each treatment presented favorable characteristics allowing its use in different strategies in ruminant nutrition.(AU)

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RESUMO

Given the difficulty in controlling dayflower, the aim was to identify what herbicide provides the better control of Commelina benghalensis and the better developmental stage for its application. The plants were grown in pots containing 2 L Bioplant substrate and soil being maintained throughout the trial at a greenhouse. Experimental design was completely randomized with four replications in factorial 8 x 5, so seven herbicides in recommended commercial rates (atrazine, carfentrazone, flumioxazin, glyphosate, MSMA, nicosulfuron and paraquat) and control applied at 5 phenological stages adjusted to BBCH scale. It was observed that the plant phenological stage affects the efficiency of chemical control. Plants at early development stages (BBCH 11 and 12) were more susceptible to herbicides, occurring control in its entirety only with atrazine, carfentrazone, MSMA and paraquat. Despite suffering injuries, C. benghalensis showed tolerance to others treatments.

Em face a dificuldade no controle da trapoeraba, o objetivo deste trabalho foi identificar qual herbicida proporciona o melhor controle de Commelina benghalensis e qual o melhor estádio fenológico para sua aplicação. As plantas foram cultivadas em vasos de 2 L contendo substrato Bioplant e solo, sendo mantidas durante todo o experimento em casa de vegetação. O delineamento experimental utilizado foi inteiramente casualizado com 4 repetições, em esquema fatorial 8 x 5, composto por sete herbicidas em (atrazina, carfentrazone, flumioxazin, glyphosate, MSMA, nicosulfuron, paraquat) e uma testemunha, aplicados em 5 estádios fenológicos ajustados à escala BBCH. Observou-se que o estádio fenológico das plantas tem influência na eficiência do controle químico. Plantas em estádios iniciais de desenvolvimento (BBCH 11 e 12) mostraram-se mais suscetíveis aos herbicidas, ocorrendo controle em sua totalidade somente com atrazina, carfentrazone, MSMA e paraquat. Apesar de sofrer fortes injúrias a C. benghalensis apresentou tolerância aos demais tratamentos não ocorrendo a morte das plantas.

Assuntos