RESUMO A introdução da soja tolerante a 2,4-D (ENLIST®) oferece um novo potencial para a aplicação de herbicidas. Dessa forma, o presente trabalho teve como objetivo: (a) avaliar o efeito das combinações de herbicidas pós-emergentes no controle de Conyza spp., e (b) a seletividade da associação de herbicidas pós-emergentes em soja, garantindo uma aplicação eficaz sem comprometer a saúde da cultura. Um experimento de campo com soja tolerante ao 2,4-D utilizou um delineamento experimental de blocos casualizados, com 14 tratamentos em quatro repetições. Os tratamentos incluíram várias combinações de 2,4-D com glifosato, chlorimuron, cloransulam, imazethapyr, bentazona e imazamox. Estes foram aplicados como um único tratamento ou sequencialmente 15 dias após o tratamento (DAT) usando glufosinato de amônio, juntamente com dois controles sem aplicação de herbicida. Os resultados mostraram menos de 15% de fitotoxicidade em todos os tratamentos. Aos 21 DAT, apenas os tratamentos aplicados sequencialmente mostraram controle significativo, com eficácia superior a 80% contra Conyza spp. Em contraste, as aplicações únicas das combinações de herbicidas com 2,4-D foram ineficazes para o controle pós-emergência de Conyza spp. 2,4D 24D D 2,4 2 4 ENLIST® ENLIST (ENLIST® forma objetivo (a pósemergentes pós emergentes spp b (b cultura casualizados 1 repetições glifosato chlorimuron cloransulam imazethapyr imazamox DAT (DAT amônio herbicida significativo 80 contraste pósemergência emergência 4D 24 2, (ENLIST 8

ABSTRACT The introduction of 2,4-D-tolerant soybeans (ENLIST®) offers a new potential for herbicide application. Therefore, the present study aimed to (a) evaluate the effect of combinations of post-emergent herbicides on the control of Conyza spp. and (b) assess the selectivity of the post-emergent herbicide association in soybeans, ensuring effective application without compromising the health of the crop. A field experiment with 2,4-D-tolerant soybeans utilized a randomized complete block design with 14 treatments across four replications. Treatments included various combinations of 2,4-D with glyphosate, chlorimuron-ethyl, cloransulam-methyl, imazethapyr, bentazon, and imazamox. These were applied either as a single treatment or sequentially 15 days after treatment (DAT) using glufosinate-ammonium alongside two controls without herbicide application. The results showed less than 15% control across all treatments. At 21 DAT, only the treatments applied sequentially showed significant control, with effectiveness exceeding 80% against Conyza spp. In contrast, the single applications of the herbicide combinations with 2,4-D were ineffective for post-emergence control of Conyza spp. 2,4Dtolerant 24Dtolerant Dtolerant 2,4 D tolerant 2 4 ENLIST® ENLIST (ENLIST® Therefore (a postemergent post emergent spp b (b crop 1 replications 2,4D 24D glyphosate chlorimuronethyl, chlorimuronethyl chlorimuron ethyl, ethyl chlorimuron-ethyl cloransulammethyl, cloransulammethyl cloransulam methyl, methyl cloransulam-methyl imazethapyr bentazon imazamox DAT (DAT glufosinateammonium glufosinate ammonium 80 contrast postemergence emergence 4Dtolerant 24 2, (ENLIST 4D 8

Abstract Introduction. Sweet potato (Ipomoea batatas (L) Lam.) is sensitive to weed competition, and chemical control in Costa Rica is challenging due to limited local information on herbicide selectivity. Objective. To determine the selectivity of six herbicides applied at different stages of development to Criollo sweet potatoes and their effect on coverage, biomass, and crop yield. Materials and methods. Between August and December 2021, three experiments were conducted at the Fabio Baudrit Moreno Agricultural Experimental Station, Universidad de Costa Rica, Alajuela, Costa Rica. Herbicides were applied (in kg a.i. ha-1) as follows: a) Experiment 1: 0.36 of metribuzin, 1.50 of pendimethalin, 0.48 of clomazone, 0.075 of halosulfuron, 1.00 of linuron, and 1.25 of metolachlor, applied six days after planting (dap) in a randomized block design with four repetitions; b) Experiment 2: 1.00 of linuron and 0.36 of metribuzin 0.36, applied at -1, 15 and 30 dap, in a randomized block design with a 2x3 factorial arrangement and three repetitions; and c) Experiment 3: 0.075 of halosulfuron and 0.36 of metribuzin, mixed with 0.125 of fluazifop-p-butyl in a randomized block design with three repetitions. Weeding was performed at 15 and 30 dap in all cases. Results. Root yield was not affected in any of the three experiments. Experiment 1: Only halosulfuron caused mild damage to the plants; no herbicide affected above-ground biomass production. Experiment 2: Only linuron and metribuzin applied at 15 and 30 dap caused mild damage. Experiment 3: The mixtures caused temporary damage to the plants. Conclusions. The evaluated herbicides were selective to the Criollo sweet potatoes, and did not affect the yield of marketable storage roots. Only halosulfuron caused mild damage in all application forms, and metribuzin and linuron only in late applications.

Resumen Introducción. El camote (Ipomoea batatas (L) Lam) es sensible a la competencia por arvenses, cuyo control químico en Costa Rica se dificulta por la limitada información local generada sobre selectividad de herbicidas. Objetivo. Determinar la selectividad de seis herbicidas aplicados en diferentes etapas de desarrollo al camote Criollo y su efecto en la cobertura, biomasa y rendimiento del cultivo. Materiales y métodos. Entre agosto y diciembre 2021, se realizaron tres experimentos en la Estación Experimental Agrícola Fabio Baudrit Moreno, Universidad de Costa Rica, Alajuela, Costa Rica. Estos incluyeron la aplicación de herbicidas (en kg i.a. ha-1) de la siguiente manera: a) experimento 1: 0,36 de metribuzin, 1,50 de pendimetalina, 0,48 de clomazone, 0,075 de halosulfuron, 1,00 de linuron y 1,25 de metolaclor, aplicados seis días después de la siembra (dds) en diseño de bloques al azar con cuatro repeticiones; b) experimento 2: 1,00 de linuron y 0,36 de metribuzin, aplicados a los -1, 15 y 30 dds, en diseño de bloques al azar con arreglo factorial 2x3 y tres repeticiones; y c) experimento 3: 0,075 de halosulfuron y 0,36 de metribuzin, mezclado con 0,125 de fluazifop-p-butil en diseño de bloques al azar con tres repeticiones. En todos los casos se realizó deshierba 15 y 30 dds. Resultados. En ninguno de los tres experimentos se vio afectada la producción de raíces reservantes. Experimento 1: solo el halosulfuron causó daños leves en las plantas; ningún herbicida afectó la producción de biomasa aérea. Experimento 2: solo el linuron y metribuzin aplicados 15 y 30 dds causaron daños leves. Experimento 3: las mezclas causaron daños temporales en las plantas. Conclusiones. Los herbicidas evaluados fueron selectivos al camote variedad Criollo y no afectaron el rendimiento de raíces reservantes comercializables; solo halosulfuron causó daños leves en todas las formas de aplicación, y metribuzin y linuron solo en aplicaciones tardías.

ABSTRACT Among weed control methods, chemical control using herbicides is one of the most widely employed due to its practicality and efficiency. However, there is still a lack of reliable information regarding the effectiveness of low-volume spraying and the droplet spectrum for contact herbicides, such as fomesafen. The objective was to determine the spray volume and droplet spectrum for applying the fomesafen herbicide and its efficacy in controlling hairy beggarticks (Bidens pilosa) and littlebell (Ipomoea triloba). The herbicide was applied using a CO2-pressurized knapsack sprayer with TT11002 spray tip spaced at 0.50 m, operating at pressures of 100 kPa (very coarse droplets) and 400 kPa (medium-sized droplets) with spray volumes of 35, 70, 140, and 280 L ha-1, obtained by varying the application speed. At the time of application, the percentage of covered area and droplet density (droplets cm-²) were evaluated on water-sensitive paper labels using the DropScope® program. The best control results for hairy beggarticks were achieved when the application was performed with very coarse droplets at a pressure of 100 kPa, with a spray volume between 65 and 280 L ha-1, droplet density exceeding 60 droplets cm-2, and coverage greater than 10%. Fomesafen does not provide effective control of littlebell. methods efficiency However lowvolume low Bidens pilosa Ipomoea triloba. triloba . triloba) CO2pressurized COpressurized CO2 pressurized CO TT TT1100 050 0 50 0.5 m 10 40 mediumsized medium sized 35 70 140 28 ha1, ha1 ha 1, 1 ha-1 speed cm² cm ² cm-² watersensitive water sensitive DropScope program 6 cm2, cm2 2, 2 cm-2 10% TT110 05 5 0. 4 3 7 14 ha- cm- TT11 TT1

RESUMO Dentre os métodos de controle de plantas daninhas, o químico, por meio de herbicidas, é um dos mais utilizados devido à sua praticidade e eficiência. No entanto, ainda faltam informações confiáveis sobre a eficácia de aplicações em baixo volume e o espectro de gotas a ser utilizado para herbicidas de contato, como o fomesafen. O objetivo deste trabalho foi determinar o volume de calda e espectro de gotas para aplicação do herbicida fomesafen, bem como a eficácia no controle de picão-preto (Bidens pilosa) e corda-de-viola (Ipomoea triloba). O herbicida foi aplicado utilizando pulverizador pressurizado por CO2, com pontas TT11002 espaçadas de 0,50 m, operando nas pressões de 100 kPa (gotas muito grossas) e 400 kPa (gotas médias) nos volumes de calda de 35, 70, 140 e 280 L ha-1, obtidos por meio da variação na velocidade de aplicação. No momento da aplicação foram avaliados a porcentagem de área coberta e a densidade de gotas (gotas cm-²) em etiquetas de papel hidrossensível, utilizando o programa DropScope®. Melhores índices de controle do picão-preto são obtidos quando a aplicação foi realizada com gotas muito grossas, na pressão de 100 kPa, com volume de calda entre 65 e 280 L ha-1, densidade de gotas superior a 60 gotas cm-2 e cobertura maior que 10%. O fomesafen não controla a corda-de-viola. daninhas químico eficiência entanto contato picãopreto picão preto Bidens pilosa cordadeviola corda viola Ipomoea triloba. triloba . triloba) CO2 CO TT TT1100 050 0 50 0,5 m 10 grossas 40 médias 35 70 14 28 ha1, ha1 ha 1, 1 ha-1 cm² cm ² cm-² hidrossensível DropScope DropScope® 6 cm2 2 cm- 10% cordadeviola. viola. TT110 05 5 0, 4 3 7 ha- TT11 TT1

ABSTRACT Lowland rice in Santa Catarina (SC), Brazil, is grown as a sole crop, which has aggravated problems with weeds. In this context, the objective of this study was to evaluate the efficacy of weed management systems in soybean crops to decrease weed infestation in lowland rice production areas, using pre- and post-emergence herbicides. The experiment was conducted in Turvo, SC, from August 2021 to April 2022. A randomized block design with four replications was used, in a 6 × 5 factorial arrangement. The factors consisted of six pre-emergence herbicides treatments (S-metolachlor, diclosulam, sulfentrazone, sulfentrazone + diuron, pyroxasulfone + flumioxazin, and a control without herbicide), and five post-emergence herbicide treatments: control without herbicide, glyphosate at two rates (930 and 1,550 g a.e. ha-1), applied alone or in combination with clethodim. The herbicide sulfentrazone caused persistent phytotoxicity and resulted in the lowest soybean grain yield. The herbicide S-metolachlor was ineffective in controlling weed species, except barnyard grass, even when combined with post-emergence application. The poor control of these weed species does not result in significant interference, causing no significant decreases in grain yield of soybean crops grown in floodplain soils. The use of S-metolachlor, diclosulam, and pyroxasulfone + flumioxazin, combined with post-emergence application of glyphosate (930 g a.e. ha-1), resulted in highly effective control of barnyard grass, inhibiting weed seed production. Only the combination of glyphosate (1,550 g a.e. ha-1) with clethodim can suppress barnyard grass seed production without using pre-emergence herbicides. SC , (SC) Brazil crop weeds context areas pre postemergence post emergence Turvo 202 2022 used arrangement preemergence Smetolachlor, Smetolachlor S metolachlor, metolachlor (S-metolachlor diclosulam diuron flumioxazin herbicide) 930 (93 1550 1 550 1,55 ae e a.e ha1, ha1 ha interference soils (1,55 ha-1 (SC 20 93 (9 155 55 1,5 (1,5 ha- 2 9 ( 15 1, (1, (1

RESUMO O arroz irrigado em Santa Catarina é cultivado em monocultivo, o que tem agravado os problemas com plantas daninhas. Deste modo, o objetivo deste estudo foi avaliar a eficiência de sistemas de manejo de plantas daninhas na cultura da soja sobre a redução da infestação de plantas daninhas em uma área de produção de arroz irrigado, utilizando para isso herbicidas em pré e/ou pós-emergência da soja. O experimento foi conduzido no município de Turvo - SC no período de agosto de 2021 a abril de 2022. Utilizou-se o delineamento de blocos casualizados com tratamentos organizados em esquema fatorial 6 × 5, com quatro repetições. O fator A constou de seis tratamentos aplicados em pré-emergência, os herbicidas utilizados foram: S-metolachlor, diclosulam, sulfentrazone, sulfentrazone + diuron, pyroxasulfone + flumioxazin, além de uma testemunha sem herbicida. Já o fator B constou de cinco tratamentos aplicados em pós-emergência: testemunha sem herbicida, gyphosate em duas doses (930 e 1550 g e.a. ha-1), aplicadas de forma isoladas ou em associação com clethodim. O herbicida S-metolachlor foi ineficiente para o controle de outras plantas daninhas, mesmo quando combinado com a aplicação em pós-emergência. O controle deficiente destas espécies não resulta em significativa interferência, não causando decréscimo na produtividade de grãos da soja, em ambientes de terras baixas. O uso dos herbicidas S-metolachlor, diclosulam e pyroxasulfone + flumioxazin, combinados com a aplicação em pós-emergência de glyphosate (930 g e.a. ha-1) resultou em controle eficiente de capim-arroz e inibiu a produção de sementes. Apenas a associação de glyphosate (1550 g e.a. ha-1) com clethodim suprimiu a produção de sementes de capim-arroz, sem a aplicação de herbicidas em pré-emergência. monocultivo modo eou pósemergência pós emergência 202 2022 Utilizouse Utilizou se 5 repetições préemergência, préemergência emergência, pré-emergência foram Smetolachlor, Smetolachlor S metolachlor, metolachlor diuron flumioxazin 930 (93 155 ea e.a ha1, ha1 ha 1 , pósemergência. emergência. interferência baixas ha-1 capimarroz capim (155 capimarroz, arroz, préemergência. 20 93 (9 15 ha- (15 2 9 ( (1

Abstract Introduction: Glyphosate is the most widely used herbicide worldwide and in Brazil. There is currently increasing concern about the effects of glyphosate on human health. The Brazilian Institute for Consumer Protection showed data on the presence of glyphosate in some of Brazil’s most consumed ultra-processed products. Currently, regulations on the upper limit for these residues in ultra-processed foods have yet to be established by the National Health Surveillance, and ultra-processed food consumption is independently associated with an increased risk of incident chronic kidney disease. Methods: Since an unbalanced diet can interfere with kidney function, this study aims to investigate the effect of daily intake of 5 mg/kg bw glyphosate in conjunction with a balanced diet and the possible impact on renal function in rats. Kidney function, kidney weight, markers of renal injury, and oxidative stress were evaluated. Results: There was a decrease in kidney weight. The main histopathological alterations in renal tissues were vacuolation in the initial stage and upregulation of the kidney injury marker KIM-1. Renal injury is associated with increased production of reactive oxygen species in mitochondria. Conclusion: This study showed changes in the kidney of rats exposed to a balanced diet with glyphosate, suggesting a potential risk to human kidney. Presumably, ultra-processed food that contain glyphosate can potentiate this risk. The relevance of these results lies in drawing attention to the need to regulate glyphosate concentration in ultra-processed foods in the future. Introduction Brazil health Brazils s ultraprocessed ultra processed products Currently Surveillance disease Methods mgkg mg kg weight evaluated Results KIM1. KIM1 KIM 1. 1 KIM-1 mitochondria Conclusion Presumably future KIM-

RESUMO Introdução: O glifosato é o herbicida mais utilizado no mundo e no Brasil. Atualmente, há uma preocupação crescente com os efeitos do glifosato na saúde humana. O Instituto Brasileiro de Defesa do Consumidor apresentou dados sobre a presença de glifosato em alguns dos produtos ultraprocessados mais consumidos no Brasil. Atualmente, as regulamentações sobre o limite máximo desses resíduos em alimentos ultraprocessados ainda não foram estabelecidas pela Vigilância Sanitária Nacional, e o consumo de alimentos ultraprocessados está independentemente associado a um risco maior de doença renal crônica incidente. Métodos: Como uma dieta desbalanceada pode interferir na função renal, este estudo tem como objetivo investigar o efeito da ingestão diária de 5 mg/kg pc de glifosato em conjunto com uma dieta equilibrada e o possível impacto na função renal em ratos. Foram avaliados função renal, peso dos rins, marcadores de lesão renal e estresse oxidativo. Resultados: Houve redução no peso dos rins. As principais alterações histopatológicas nos tecidos renais foram vacuolização no estágio inicial e regulação positiva do marcador de lesão renal KIM-1. A lesão renal está associada à produção aumentada de espécies reativas de oxigênio nas mitocôndrias. Conclusão: Esse estudo mostrou alterações nos rins de ratos expostos a uma dieta balanceada com glifosato, sugerindo um risco potencial ao rim humano. Presumivelmente, alimentos ultraprocessados que contenham glifosato podem potencializar esse risco. A relevância desses resultados está no fato de chamar a atenção para a necessidade de regulamentar a concentração de glifosato em alimentos ultraprocessados no futuro. Introdução Brasil Atualmente humana Nacional incidente Métodos mgkg mg kg oxidativo Resultados KIM1. KIM1 KIM 1. 1 KIM-1 mitocôndrias Conclusão humano Presumivelmente futuro KIM-

Abstract Glyphosate is a broad-spectrum herbicide that has been applied to agricultural fields in more than 200 countries for 40 years. Due to recent studies that demonstrated its relationship as a carcinogen, a worldwide debate has opened about its use and prohibition. Mexico has joined the movement to ban its use in the decree issued in December 2020. Due to its constant application, residual glyphosate impacts different environmental compartments, including the soil. Therefore, the objective was to identify the agricultural practices and weed management used in the ejido of Bella Esperanza, Coatepec, Veracruz, as part of the characterization of the sampling site for the research project on the bioremediation of glyphosate with endogenous microorganisms. Through a field approach, surveys were carried out with producers in the area, where the results showed that 54% use glyphosate as their primary weed control. They do not use any protective equipment either and consider glyphosate a product harmless to the environment. In the same way, the result of this study observed that the ejido of Bella Esperanza is a suitable sampling area for studying microorganisms with possible applications in bioremediation.

Resumen El glifosato es un herbicida de amplio espectro que ha sido aplicado en los campos agrícolas de más de 200 países desde hace 40 años. Debido a recientes investigaciones que demostraron su relación como cancerígeno, se ha abierto un debate a nivel mundial sobre su uso y prohibición. México se ha sumado al movimiento de prohibir su uso en el decreto emitido en diciembre de 2020. El efecto del glifosato residual debido a la aplicación constante del mismo tiene afectaciones en diferentes compartimentos ambientales, entre ellos el suelo. Por lo tanto, el objetivo fue identificar las prácticas agrícolas y manejo de arvenses que se emplean en el ejido de Bella Esperanza, Coatepec, Veracruz, como parte de la caracterización del sitio de muestreo para el proyecto de investigación en torno a la biorremediación del glifosato con microorganismos endógenos. Mediante un acercamiento de campo, se realizaron encuestas a los productores de la zona, donde los resultados mostraron que el 54% emplea el glifosato como principal control de malezas. Asimismo, no emplean ningún equipo de protección y consideran al glifosato como un producto inocuo para el medio ambiente. Del mismo modo, el resultado de este estudio observó que el ejido de Bella Esperanza es un área de muestreo adecuada para el estudio de microorganismos con posibles aplicaciones en biorremediación.

Abstract Destruction of the harvest of cotton stalks should be done after it. However, destruction by ploughing prevents continuing with direct sowing, which makes chemical management an ally in soil conservation. The objective was to identify the most effective dose of 2,4-D, associated with different herbicides and the timing of administration for the control of transgenic cotton shoots for tolerance to glyphosate and glufosinate. The treatments consisted of the use of the herbicide 2,4-D, alone at doses of 670 and 1 340 g ha-1, and associated with the herbicides carfentrazone, flumiclorac, chlorimuron, flumioxazin and imazethapyr at three application times: 0 days after mechanical mowing (0 DAMM), 25 DAMM, and 0 DAMM + 25 DAMM. Regrowth evaluations were performed at 15, 30, and 45 days after the first and second applications, determining the dry biomass of the shoots. In terms of herbicide use time, the best results are obtained when they applied at 0 DAMM + 25 DAMM. Higher doses of 2,4-D (1 324 g ha-1) make it more efficient; in relation to herbicides, variations were perceived in their behavior depending on the time of evaluation, the application, and the dose of 2,4-D used. During the last measurement period, 45 days after application, 2,4-D+carfentrazone and 2,4-D+flumiclorac had the lowest dry shoot masses. The experiment was conducted in 2014. It was concluded that there is a lower rate of cotton regrowth when the application of the herbicides is repeated at 0 DAMM and 25 DAMM. The 1 324 g ha-1 dose of 2,4-D is more efficient. 2,4-D+carfentrazone and 2,4-D+flumiclorac promoted lower dry mass 45 days after administration of the treatments.

Resumen La destrucción de la cosecha de tallos de algodón debe realizarse después de esta. Sin embargo, la destrucción por arado impide continuar con la siembra directa, lo que hace que el manejo químico sea un aliado en la conservación del suelo. El objetivo fue identificar la dosis de 2,4-D, asociada a diferentes herbicidas y el momento de administración más eficazes para el control de retoños de algodón transgénico para tolerancia a glyphosate y glufosinate. Los tratamientos consistieron en el uso aislado del herbicida 2,4-D, a dosis de 670 y 1 340 g ha-1, y asociado a los herbicidas carfentrazone, flumiclorac, chlorimuron, flumioxazin y imazethapyr en tres tiempos de aplicación: 0 días después de la siega mecánica (0 DARM), 25 DARM, y 0 DARM + 25 DARM. Se evaluó el rebrote a los 15, 30 y 45 días después de la primera y segunda aplicación. Las evaluaciones de rebrote se realizaron a los 15, 30 y 45 días después de la primera y segunda aplicación, determinando la biomasa seca de los brotes. En cuanto al tiempo de uso de los herbicidas, los mejores resultados se obtienen cuando se suministró 0 DARM +25 DARM. Dosis más altas de 2,4-D (1 324 g ha-1) lo hacen más eficiente relaciona a los herbicidas se percibieron variaciones en su comportamiento según el tiempo de evaluación, la aplicación y la dosis de 2,4 D utilizada. Durante el último período de medición, 45 días después de la aplicación, 2,4-D+carfentrazone y 2,4-D+flumiclorac presentaron las masas secas de yema más bajas. El experimento se llevó a cabo en 2014. Se concluyó que existe una menor tasa de rebrote del algodón cuando se repite la aplicación de los herbicidas 0 DARM y 25 DARM. La dosis de 1 324 g ha-1 de 2,4-D es más eficiente. 2,4-D+carfentrazona y 2,4-D+flumiclorac promovieron una menor masa seca 45 días después de la administración de los tratamientos.

Abstract Paraquat®, or N,N‘-dimethyl-4,4‘-bipyridinium dichloride, is a bipyridyl compound used as a non-selective herbicide and desiccant that can cause acute poisoning through all routes of exposure. There is no known antidote, and the available treatments are based on avoiding its absorption and timely removing it, in adults and children. We describe a case series of 14 pediatric patients from the department of Cauca, Colombia, with acute intoxication after oral intake of paraquat. Patients were referred to a medium-high complexity hospital in southwestern Colombia and treated according to an institutional protocol for acute paraquat poisoning. Acute paraquat poisoning after oral ingestion is associated with a high mortality rate, even with timely medical attention, as the compound has no known antidote and quickly reaches systemic concentrations for fulminant poisoning. Based on the available literature, our center has proposed a clinical protocol including early standard management, immunosuppressive and antioxidant treatments, and systemic removal techniques. This protocol suggests an adequate approach to acute paraquat poisoning in the pediatric population.

Resumen El dicloruro de 1,1’-dimetil-4,4’-bipiridilo (Paraquat®) es un compuesto químico de la familia de las piridinas, utilizado como herbicida no selectivo y desecante. Este compuesto puede causar intoxicación aguda por todas las vías de exposición. En el momento, no hay un antídoto conocido y los tratamientos disponibles, incluidos los pediátricos, se basan en contrarrestar su absorción y propiciar su remoción oportuna. Se describe una serie de casos de 14 pacientes pediátricos, procedentes en su mayoría del departamento del Cauca, con intoxicación aguda por ingestión de paraquat. Los pacientes fueron remitidos y atendidos en un hospital de mediana a alta complejidad en el suroccidente colombiano, con un protocolo institucional para el manejo de la intoxicación aguda por el herbicida. La intoxicación aguda con paraquat por vía oral se asocia con una alta tasa de mortalidad, aún con atención médica oportuna, pues fácilmente se alcanzan concentraciones sistémicas para ser fulminante. Basado en la literatura disponible, el Hospital Universitario San José ha propuesto un protocolo clínico -adecuado para la intoxicación aguda por paraquat en población pediátrica- que incluye manejo estándar temprano, tratamiento inmunosupresor y antioxidante, y técnicas para su remoción sistémica

Abstract The widespread use of herbicides has contributed to the evolution of resistance in many weed species, including Digitaria sanguinalis (DIGSA), a grass important as weed that presents presents biotypes with different resistance mechanisms to acetolactate synthase (ALS)-inhibiting herbicides. Within the framework of eco-evolutionary dynamics in agroecosystems, it is important to pay attention to ecological interactions, such as those between plants and pathogens, since they could affect herbicide-resistant (R) and herbicide-susceptible (S) biotypes differently. One of these biotic interactions is the one established between DIGSA and Ustilago syntherismae, a fungus whose infection can prevent seed production in plants. An experiment has been carried out in which teliospores of the fungus have been placed in contact with seeds of R and S biotypes of DIGSA, applying a vacuum, in order to evaluate their infection by the fungus. The seeds were germinated in Petri dishes at 20°C 12h darkness / 30°C 12h light. After 10 days, the seedlings were cleared, stained and observed under an optical microscope to detect the systemic infection. The proportion of infected seedlings was subjected to statistical analysis. The results showed that the mean percentage of infection was significantly higher in the R biotype (98.4%) than in the S biotype (93.7%). Further studies are necessary to evaluate the possibility that herbicide resistance may have fitness costs in the plant-pathogen interaction.

Resumen El amplio uso de herbicidas ha contribuido a la evolución de la resistencia en muchas especies de malas hierbas, entre ellas Digitaria sanguinalis (DIGSA) una gramínea importante como arvense que presenta biotipos resistentes a herbicidas inhibidores de la acetolactato sintasa (ALS). En el marco de la dinámica eco-evolutiva en los agroecosistemas es importante prestar atención a las interacciones ecológicas, como por ejemplo las que se dan entre plantas y patógenos, puesto que podrían afectar de forma distinta a biotipos resistentes (R) y susceptibles (S) a herbicidas. Una de estas interacciones bióticas es la que se establece entre DIGSA y Ustilago syntherismae, hongo cuya infección puede llegar a evitar la producción de semilla en las plantas. Se ha llevado a cabo un experimento en el que se han puesto en contacto teliósporas del hongo con semillas de biotipos R y S de DIGSA, aplicando vacío, con el fin de evaluar su infección por el hongo. Las semillas germinaron en placas de Petri a 20°C 12h oscuridad / 30°C 12h luz y las plántulas fueron analizadas 10 días después. Se transparentaron, tiñeron y observaron al microscopio óptico para detectar la infección sistémica. La proporción de plántulas infectadas se sometió a un análisis estadístico. Los resultados mostraron que el porcentaje medio de infección fue significativamente mayor en el biotipo R (98,4 %) que en el S (93,7 %). Son necesarios más estudios para evaluar la posibilidad de que la resistencia al herbicida pueda penalizar la aptitud biológica en la interacción planta-patógeno.

Abstract Bassia scoparia is an annual plant of the Amaranthaceae family commonly found in regions of North America, Asia and Europe. It has developed resistance to several herbicide modes of action, including multiple resistance, making it difficult to control and requiring integrated management to address its problem. In 2022, seeds were collected from plants in a winter cereal field under no-tillage from Guissona (GUI-R) in Catalonia, survivors of successive treatments with auxin herbicides and ALS and EPSPS inhibitors. The sensitive reference population came from Aragon (A17-S), harvested in 2017. Dose-response assays were performed, on seedlings with four leaves (BBCH 14), two different herbicide modes of action and data collection 28 days after treatment. Values for R and S populations, respectively, were: glyphosate (HRAC 9) doses between 135 - 2,160 g a.e. ha-1 and 33.75 - 1,080 g a.e. ha-1, GR50 values of 255 and 129 a.e. ha-1, RF of 2 and LD50 of 389 and 1. 240 a.i. ha-1 and RF of 3.2 times; thifensulfuron (HRAC 2) 7.5 - 480 a.i. ha-1 and 0.24 - 7.5 a.i. ha-1, GR50 values of 480 and 3.9 a.i. ha-1, RF of 123 and LD50 undetermined due to high survival of the R population. Molecular studies are currently underway to elucidate the resistance mechanism involved and dose-response assays with three auxin herbicides (HRAC 4): 2,4-D, dicamba and MCPA.

Resumen Bassia scoparia es una planta anual de la familia Amaranthaceae que se encuentra comúnmente en regiones de América del Norte, Asia y Europa. Ha desarrollado resistencia a varios modos de acción herbicida, incluida la resistencia múltiple, lo que dificulta su control y requiere de una gestión integrada para abordar su problemática. En 2022 se recolectaron semillas de plantas de un campo de cereales de invierno bajo siembra directa, procedentes de Guissona (GUI-R) en Cataluña, supervivientes a tratamientos sucesivos con herbicidas auxínicos e inhibidores de la ALS y EPSPS. La población sensible de referencia procedía de Aragón (A17-S), cosechada en el 2017. Se realizaron ensayos de dosis - respuesta, en plántulas con cuatro hojas (BBCH 14), tres modos de acción herbicida diferentes y toma de datos 28 días después del tratamiento. Las dosis evaluadas de herbicidas para las poblaciones R y S, respectivamente, fueron: glifosato (HRAC 9) dosis entre 135 - 2.160 g e.a. ha-1 y 33.75 - 1.080 g e.a. ha-1, valores GR50 de 255 y 129 g e.a. ha-1, RF de 2 y LD50 de 389 y 1.240 g e.a. ha-1 y RF de 3.2 veces; tifensulfuron (HRAC 2) 7.5 - 480 g e.a ha-1 y 0.24 - 7.5 g e.a. ha-1, valores GR50 de 480 y 3.9 g e.a. ha-1, RF de 123 y LD50 indeterminada por la alta supervivencia de la población R. Actualmente se desarrollan estudios moleculares para dilucidar el mecanismo de resistencia involucrado y ensayos de dosis-respuesta con tres herbicidas auxínicos (HRAC 4): 2,4-D, dicamba y MCPA.

Abstract Sorghum halepense (Johnsongrass) is a weed that tends to spatially distribute in an aggregated manner in maize crops. In a two-year study conducted at La Poveda (CSIC, Madrid), the effectiveness of Precision Agriculture (PA) in controlling this weed was investigated by: 1) monitoring the spatio-temporal dynamics of Johnsongrass patches in a maize field using UAV aerial image processing; 2) site-specific application of the herbicide nicosulfuron according to the early-stage map generated from aerial imagery; and 3) quantification of crop yield in Johnsongrass treated and untreated areas, as well as weed-free. The analysis of the map prior to herbicide treatment in 2022 revealed a random distribution of Johnsongrass, with patches averaging 0.4 m² in size, ranging from 0.01 m² to 5 m². Site-specifically treated plots showed spatial growth control, evidenced in the subsequent season (2023) with an average patch size of 1.0 m2, ranging from 0.02 m² to 12 m². In contrast, untreated patches significantly increased in size (average 3.8 m2; ranging between 0.01 m² and 122 m²). There was a notable decrease in yield in untreated infested areas compared to treated and/or Johnsongrass-free areas. These findings underscore the advantages of PA in Johnsongrass control, demonstrating how detection and site-specific patch management can reduce herbicide use by up to 95% and mitigate competition with the maize crop.

Resumen Sorghum halepense (cañota) es una mala hierba que tiende a distribuirse espacialmente de forma agregada en los cultivos de maíz. En un estudio de dos años realizado en La Poveda (CSIC, Madrid), se investigó la eficacia de la Agricultura de Precisión (AP) en su control, mediante: 1) el seguimiento de la dinámica espacio-temporal de los rodales de cañota en un campo de maíz con el procesamiento de imágenes aéreas UAV; 2) la aplicación localizada del herbicida nicosulfuron según el mapa generado en etapa temprana con imágenes aéreas; y 3) la cuantificación del rendimiento del cultivo en áreas tratadas y no tratadas con cañota, así como libres de mala hierba. El análisis del mapa previo al tratamiento herbicida en 2022 reveló una distribución aleatoria de cañota, con rodales de tamaño medio de 0,4 m2, variando entre 0,01 m² y 5 m². Las parcelas tratadas con herbicida localizado mostraron un control del crecimiento espacial, evidenciado en la campaña siguiente (2023) con un tamaño promedio de 1,0 m2, oscilando entre 0,02 m² y 12 m². En contraste, los rodales no tratados aumentaron significativamente su tamaño (media 3,8 m2; rango entre 0,01 m² y 122 m²). El rendimiento disminuyó notablemente en zonas infestadas sin tratamiento respecto a las zonas tratadas y/o libres de cañota. Estos resultados subrayan las ventajas de la AP en el control de la cañota, demostrando cómo la detección y manejo localizado de rodales podrían reducir hasta un 95% el uso de herbicidas y mitigar la competencia con el cultivo de maíz.

Abstract The tripeptide glutathione has been related to the oxidative stress elicited in the mode of action of several types of herbicides. Beside this, glutathione-S-transferases (GSTs) enzymes can detoxify xenobiotics through their conjugation with glutathione. Such enzymatic conjugation and herbicide metabolization has been described as a type of non-target-site (NTS) resistance mechanism for some herbicides, including acetolactate synthase (ALS) inhibitors. The objective of this work is to compare glutathione metabolism after ALS inhibition and determine the role of GSTs enzymes in the NTS resistance in one Amaranthus palmeri population to ALS inhibitors. The content of metabolites related to glutathione, the enzymatic activity and the gene expression of GSTs have been determined after the individual and joint application of nicosulfuron and a GST inhibitor (NBD-Cl) in two populations (resistant to the sulfonylurea nicosulfuron and sensitive). The results showed an increase in the synthesis of glutathione and its related components in the sensitive population after herbicide treatment, as well as an increase in GST activity. The resistant population presented a higher basal GST activity than, the sensitive population but the herbicide did not induce glutathione synthesis, activity, or GST expression in the resistant population. Thus, the involvement of GSTs as a physiological NTS mechanism for nicosulfuron could not be confirmed in the studied population.

Resumen El glutatión es un tripéptido que se ha relacionado con el estrés oxidativo detectado dentro del modo de acción de ciertos herbicidas. Por otro lado, las enzimas glutatión-S-transferasas (GSTs) son capaces de detoxificar xenobióticos a través de su conjugación con glutatión. Esta conjugación enzimática se ha descrito como un tipo de mecanismo de resistencia non-target-site (NTS) para algunos herbicidas, incluyendo los inhibidores de la acetolactato sintasa (ALS). El objetivo de este trabajo es estudiar el metabolismo del glutatión en respuesta a inhibidores de ALS y determinar la implicación de las enzimas GSTs en la resistencia NTS de una población de Amaranthus palmeri. Se han determinado el contenido de los metabolitos relacionados con el glutatión, la actividad enzimática y la expresión génica de las GSTs tras la aplicación individual y conjunta de nicosulfurón y un inhibidor de GSTs (NBD-Cl) en dos poblaciones (resistente a la sulfonilurea nicosulfurón y sensible). El tratamiento con nicosulfurón en la población sensible indujo un incremento en la síntesis de glutatión y actividad GST. La población resistente presentó una mayor actividad basal GST que la población sensible pero el herbicida no indujo la síntesis de glutatión, ni la actividad ni la expresión de GST, con lo que no se puede confirmar la implicación de las GSTs como mecanismo fisiológico NTS a nicosulfurón en la población estudiada.

Abstract Citral is a secondary metabolite found in the composition of many essential oils from plants, such as the essential oil of Cymbopogon citratus (DC.) Stapf, in which it is the major constituent. Citral has been demonstrated to possess several biological activities, among them herbicidal activity, so it has a high potential for the development of natural herbicides. In this work, the phytotoxic potential of citral was studied on two weeds, Avena fatua L. (monocotyledonous) and Chenopodium album L. (dicotyledonous). The tests were carried out under greenhouse conditions at the Universitat Politècnica de València. Citral was tested at different concentrations applied by spraying in post-emergence when the plants had 2-3 leaves in the case of A. fatua and 4-6 leaves in the case of C. album. The results showed high efficacy of citral as herbicide under greenhouse conditions. Trials on other species and under field conditions would be necessary to verify its herbicidal potential under real conditions, but it was shown to be a good candidate for bioherbicide formulations.

Resumen El citral es un metabolito secundario que se encuentra en la composición de muchos aceites esenciales de plantas, como por ejemplo en el aceite esencial de Cymbopogon citratus (DC.) Stapf, en el que es el componente mayoritario. Se trata de una molécula con diferentes propiedades biológicas, entre ellas, se ha demostrado su actividad herbicida, lo que le confiere un elevado potencial como base para el desarrollo de herbicidas naturales. En este trabajo, se ha estudiado el potencial fitotóxico del citral sobre dos arvenses, Avena fatua L. (moconotiledónea) y Chenopodium album L. (dicotiledónea). Los ensayos se llevaron a cabo en condiciones de invernadero en la Universitat Politècnica de València. Se probó el citral a diferentes concentraciones aplicado mediante pulverización en post emergencia sobre las plantas arvenses cuando tenían 2-3 hojas en el caso de A. fatua y 4-6 hojas para C. album. Los resultados mostraron una elevada efectividad del citral como herbicida en condiciones de invernadero. Sería necesario realizar ensayos sobre otras especies y en condiciones de campo, para verificar su potencial herbicida en condiciones reales, pero se demostró que puede ser un buen candidato para la formulación de bioherbicidas.

Abstract Spain is the main black truffle (Tuber melanosporum Vittad.) producer in the world. Weed control in these plantations is a key factor to guarantee the correct development of the trees and is usually carried out by means of mechanical weeding. During the first years of tree establishment this technique is normally combined with herbicide use trying not to reach the trunks of the saplings. However, there is concern and interest in the sector to find an alternative method to avoid possible mycotoxicity and hangover in the truffles. In April 2022 two different hydromulches were applied in young plantations to compare them with manual weeding and herbicide application in two plots of Graus (Huesca). Weed soil cover was assessed periodically up to 413 days after application and tree growth was assessed every 6 months. In one of the plots weed pressure was lower reaching 22% in one of the samplings prior to mechanical weeding; in the other plot 59% was reached. In one of the plots, mean frequency and abundancy of the perennial grass Cynodon dactylon (L.) Pers. was lower for hydromulch based on rice husk. The control of annual weeds was satisfactory in both trials for any of the tested hydromulches. In one of the plots the growth of trees was slightly higher for the hydromulches compared to the plots weeded mechanically or with herbicides.

Resumen España es el primer productor mundial de trufa negra (Tuber melanosporum Vittad.). El control de las malas hierbas en estas plantaciones es clave para garantizar un desarrollo correcto de los árboles y suele llevarse a cabo mediante escarda mecánica. En los primeros años de establecimiento suele combinarse con el uso de herbicidas tratando de no rociar los tallos de los plantones. No obstante, existe preocupación e interés en el sector para encontrar un método alternativo para evitar una posible micotoxicidad y residuos en las trufas. En abril de 2022 se aplicaron dos hidroacolchados diferentes en plantaciones truferas jóvenes para compararlos con una escarda manual y una aplicación herbicida en dos fincas en Graus (Huesca). Se evaluó periódicamente la cobertura del suelo por malas hierbas hasta 413 días después de la aplicación, y se realizó un seguimiento semestral del crecimiento de los árboles. En una de las fincas, la presión de arvenses fue menor, alcanzando como máximo una cobertura del 22% en uno de los muestreos realizados antes de la escarda manual; en la otra finca, se alcanzó el 59%. En una parcela, la frecuencia y abundancia medias durante el ensayo de la especie perenne Cynodon dactylon (L.) Pers. fue inferior para el acolchado basado en cascarilla de arroz. El control de especies dicotiledóneas anuales fue satisfactorio en ambos ensayos con cualquier hidroacolchado. En una de las fincas, el crecimiento de los árboles con hidroacolchados fue ligeramente mayor que en los controles escardados o tratados con herbicida.

Abstract Synthetic herbicides have been the most widely used tool for weed control since their discovery and development in the mid-20th century. However, their continued use has led to the emergence of resistant weed biotypes, reducing their efficacy. They also provoked environmental problems, affecting non-target species, and causing crop stress. It is therefore necessary to look for new herbicides that could be effective in controlling weeds while also being environmentally friendly. The essential oils of some plants have compounds with phytotoxic properties, which can inhibit the germination and growth of weeds. Carvacrol is a monoterpene phenol found mainly in the essential oils of plants of the Lamiaceae family, with proven herbicidal activity. The aim of the present work was to obtain a dose-response curve of carvacrol on Lolium rigidum (monocotyledonous weed model) and Sonchus oleraceus (dicotyledonous weed model). The tests were carried out under greenhouse conditions, applying different doses of carvacrol on the weeds studied to obtain the dose-response curves. To assess the herbicidal activity of carvacrol, its efficacy on weeds were determined. S. oleraceus was more sensitive to carvacrol than L. rigidum. The dose-response curves obtained will be used in the future as a reference for field trials and for the study of synergistic interactions of carvacrol with other compounds.

Resumen Los herbicidas sintéticos han sido la herramienta más utilizada para el control de las plantas arvenses desde su descubrimiento y desarrollo a mediados del siglo XX. Sin embargo, su uso continuado ha llevado a la aparición de biotipos de arvenses resistentes, disminuyendo su eficacia. Además, han causado problemas medioambientales, afectan a especies no diana, y pueden producir fitotoxicidad en los cultivos. Por ello, es necesario buscar nuevas materias herbicidas que sean efectivas en el control de las arvenses pero respetuosas con el medio ambiente. Los aceites esenciales de algunas plantas poseen compuestos con propiedades fitotóxicas, que pueden inhibir la germinación y el crecimiento de las arvenses. El carvacrol es un fenol monoterpénico que se encuentra principalmente en los aceites esenciales de las plantas de la familia Lamiaceae, con demostrada actividad herbicida. El objetivo del presente trabajo fue obtener una curva dosis-respuesta del carvacrol sobre las especies Lolium rigidum (modelo de arvense monocotiledónea) y Sonchus oleraceus (modelo de arvense dicotiledónea). Los ensayos se realizaron en invernadero, aplicando distintas dosis de carvacrol sobre las arvenses estudiadas a fin de obtener la curva dosis-respuesta de cada una de ellas. Para evaluar la actividad herbicida del carvacrol se determinó su eficacia. S. oleraceus fue más sensible al carvacrol que L. rigidum. La obtención de estas curvas dosis-respuesta permitirá en el futuro utilizarlas como referencia para realizar ensayos en condiciones de campo y para el estudio de interacciones sinérgicas del carvacrol con otros compuestos.