ABSTRACT: In general, allelopathy can be defined as a biological process by which an organism produces one or more metabolites that can change the germination, growth, survival, and reproduction of other organisms, and thus influencing the stability of agroecosystems. Cholesterol is a very abundant sterol isolated from the marine red alga Plocamium brasiliense that has been studied regarding its potential inhibitory effects on seed germination, radicle elongation, and hypocotyl development of the weeds Mimosa pudica (malicia) and Senna obtusifolia (mata-pasto). Cholesterol was isolated from a hexane extract by chromatographic methods. Over a 15-day period, germination bioassays were performed at 25 ºC with a 12-h photoperiod. Radicle elongation and hypocotyl development were assayed at 25 ºC with a 24-h photoperiod. Later, Petri dishes 9.0 cm in diameter were coated with filter paper, and 25 seeds were placed in a germination chamber. Six pre-germinated seeds were placed in the Petri dish for 2-3 days. After 10 days, radicle and hypocotyl extensions were measured, and the inhibitory potential of cholesterol was assessed at 5, 10, 15, and 20 ppm. In both herbs, M. pudica and S. obtusifolia, they were significantly affected by the action of cholesterol, achieving higher percentages of inhibition in seed germination (50% and 33%, respectively), radical germination (68% and 60%, respectively), and hypocotyl development (66% and 55%, respectively). The inhibition effects were dose-dependent in all experiments, having more pronounced allelopathic effects at 20ppm. ABSTRACT general growth survival organisms agroecosystems malicia (malicia matapasto. matapasto mata pasto . (mata-pasto) methods 15day day 15 period 2 12h h 12 photoperiod 24h 24 Later 90 9 0 9. paper chamber pregerminated pre germinated 23 3 2- days 1 measured 5 ppm herbs M S 50% 50 (50 33 33% respectively, respectively , respectively) 68% 68 (68 60 60% 66% 66 (66 55 55% respectively. dosedependent dose dependent experiments 20ppm (mata-pasto (5 6 (6 (

RESUMO: Em geral, alelopatia pode ser definido como o processo biológico no qual um organismo produz metabolitos que alteram a germinação, o crescimento, a sobrevivência e a reprodução de outros organismos, influenciando a estabilidade de agroecossistemas. O colesterol, o mais abundante esterol isolado da alga vermelha marinha Plocamium brasiliense, foi estudado quanto ao seu potencial efeito inibitório na germinação de sementes, alongamento das radículas e desenvolvimento do hipocótilo das ervas daninhas Mimosa pudica (malicia) e Senna obtusifolia (mata-pasto). Colesterol foi isolado do extrato em Hexano por métodos cromatográficos. Durante 15 dias, os bioensaios de germinação foram realizados a 25 ºC e fotoperíodo de 12 horas, enquanto os bioensaio de alongamento da radícula e do hipocótilo foram realizados a 25 ºC e fotoperíodo de 24 horas. Posteriormente, placas de Petri de 9,0 cm de diâmetro foram revestidas de papelfiltro, e 25 sementes foram mantidas em câmaras de germinação, enquanto seis sementes pré-germinadas foram postas em placas de Petri por 2-3 dias. Após dez dias, a extensão da radícula e do hipocótilo foi medida. O potencial inibitório do colesterol foi avaliado a 5, 10, 15 e 20 ppm. Em ambas as ervas M. pudica e S. obtusifolia, foram afetadas significativamente pela ação do cholesterol alcançando maiores percentuais de inibição na germinação das sementes (50% e 33%, respectivamente), alongamento da radícula (68% e 60%, respectivamente) e desenvolvimento do hipocótilo (66% e 55%, respectivamente). Os efeitos inibitórios foram dose-dependentes em todos os experimentos, tendo efeitos alelopaticos mais acentuados a 20 ppm. RESUMO geral crescimento organismos agroecossistemas brasiliense malicia (malicia matapasto. matapasto mata pasto . (mata-pasto) cromatográficos 1 dias 2 horas Posteriormente 90 9 0 9, papelfiltro prégerminadas pré germinadas 23 3 2- medida 5 10 ppm M S 50% 50 (50 33 33% respectivamente, respectivamente , 68% 68 (68 60 60% 66% 66 (66 55 55% respectivamente. dosedependentes dose dependentes experimentos (mata-pasto (5 6 (6 (

Abstract Introduction. Weeds are one of the main problems in agricultural productivity due to their interactions with crops, such as alelopatic effects on germination. Objective. To evaluate the allelopathy of kikuyo grass (Cenchrus clandestinus) on the germination of beans (Phaseolus vulgaris L.) variety ICA Cerinza. Materials and methods. The study was conducted at the Quality Control Laboratory of the Universidad de Pamplona, Central Campus, Pamplona, Norte de Santander, Colombia, from May to August 2022. To each experimental unit (Petri dishe) with 12 been seeds, 6 mL of kikuyo aqueous extract (leaf, stem, and root) at three concentrations (1, 2.5, and 5 %), plus a control (0 %), were added, totaling 12 treatments. From day 0 to 12, the number of germinated seeds (NGS) was recorded, and the germination rate index (GRI) and germination index (IG) were calculated. The biomolecular profile of the aqueous extract was determined using the Fourier-transform spectroscopy. A completely randomized experimental design with a factorial arrangement (3x4), with repeated measures in each experimental unit, was employed. The intersuject factors were the organ type and concentration, while the intrasubject factor was the evaluation time (12 days). Results. Significant differences (p<0.001) were observed for NSG among treatments due to the concentration of the aqueous extract, as well as for IG, while GRI depended on the organ (p<0.05) and concentration (p<0.001), both negatively affected as the concentration increased. The infrared spectrum of the extract determined the presence of polyphenols, nitriles, and siloxanes. Conclusión. C. clandestinus affected NGS, GRI, and GI of P. vulgaris, with an allelopathic effect of the leaf aqueous extract at higher concentrations. Polyphenols, nitriles, and siloxanes associated with allelopathic effects were identified in the aqueous extracts.

Resumen Introducción. Las arvenses son uno de los principales problemas en la productividad agrícola, debido a interacciones con el cultivo, como efectos alelopáticos sobre la germinación. Objetivo. Evaluar la alelopatía del pasto kikuyo (Cenchrus clandestinus) en la germinación de frijol (Phaseolus vulgaris L.) variedad ICA Cerinza. Materiales y métodos. El estudio se realizó en el laboratorio de Control de Calidad de la Universidad de Pamplona, Campus Central, Pamplona, Norte de Santander, Colombia, en mayo-agosto 2022. A cada unidad experimental (caja de Petri) con doce semillas de frijol se le agregó 6 mL de extracto acuoso de kikuyo (hoja, tallo y raíz) en tres concentraciones (1, 2,5 y 5 %), más un testigo (0 %), para un total de doce tratamientos. En el lapso de 0 a 12 días, se registró el número de semillas germinadas (NSG), se calculó el índice de tasa de germinación (ITG) y el índice de germinación (IG), y se determinó el perfil biomolecular del extracto acuoso mediante la técnica de espectroscopia transformada de Fourier. Se utilizó un diseño experimental completamente al azar con arreglo factorial (3x4), con medidas repetidas en cada unidad experimental. Los factores intersujetos fueron el tipo de órgano y concentración, y el factor intrasujeto fue el tiempo (12 días) de evaluación. Resultados. Se observaron diferencias significativas (p<0,001) para NSG entre tratamientos por efecto de la concentración del extracto acuoso al igual que para IG, mientras que ITG dependió del órgano (p<0,05) y la concentración (p<0,001); ambos fueron afectados de forma negativa conforme aumentó la concentración. En el espectro infrarrojo del extracto se determinaron polifenoles, nitrilos y siloxanos. Conclusión. C. clandestinus afectó NSG, el ITG e IG de P. vulgaris, con efecto alelopático del extracto acuoso de hoja en mayor concentración. En los extractos acuosos se determinaron polifenoles, nitrilos y siloxanos, asociados a efecto alelopático.

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 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: Effective weed control in crop fields at an early stage is a crucial aspect of modern agriculture. Nonetheless, detecting and identifying these plants in environments with unpredictable conditions remain a challenging task for the agricultural industry. Thus, a two-stage deep learning-based methodology to effectively address the issue is proposed in this work. In the first stage, multi-plant image segmentation is performed, whereas regions of interest (ROIs) are classified in the second stage. In the segmentation stage, a Deep learning model, specifically a UNet-like architecture, has been used to segment the plants within an image following two approaches: resizing the image or dividing the image into patches. In the classification stage, four architectures, including ResNet101, VGG16, Xception, and MobileNetV2, have been implemented to classify different types of plants, including corn and weed plants. A large image dataset was used for training the models. After resizing the images, the segmentation network achieved a Dice Similarity Coefficient (DSC) of around 84% and a mean Intersection over Union (mIoU) of around 74%. On the other hand, when the images were divided into patches, the segmentation network achieved a mean DSC of 87.48% and a mIoU of 78.17%. Regarding the classification, the best performance was achieved by the Xception network with a 97.43% Accuracy. Then, According to the results, the proposed approach is a beneficial alternative for farmers as it offers a method for detecting crops and weeds under natural field conditions.

Abstract Background: Roadside plants grow along transportation routes, and are little studied. Questions: What is the richness of roadside angiosperms? What is the percentage of native and introduced species for roadside angiosperms? Species studied: Native and introduced roadside angiosperms. Site and years of study: Chalma-Malinalco roadside, municipality of Malinalco, State of Mexico, Mexico, May 2008-April 2009. Methods: Angiosperm species were collected along the road right-of-way during 24 biweekly walks. Additionally, species were listed and their cover estimated in 14 sampling sites (4 m2 each). Results: We recorded 327 species. Asteraceae, Fabaceae and Poaceae were the families with the highest richness of genera and species. Native species were dominant (85.9 %), whereas introduced species grouped 14.1 %; the latter came mainly from the Old World. About 70 % of the species were herbs. Bouteloua repens and Eleusine indica had the highest cover and frequency, respectively. Conclusions: The roadside flora was rich in angiosperms, mostly herbs, and with a dominance of native plants. Introduced grasses played an outstanding role in terms of frequency. It is necessary to continue with floristic, ecological and ethnobotanical research, among others, on this group of plants that has been scarcely studied.

Resumen Antecedentes: Las plantas viarias crecen en las orillas de vías de comunicación y han sido poco estudiadas. Preguntas: ¿Cuál es la riqueza de las angiospermas viarias? ¿Cuál es el porcentaje de especies nativas e introducidas entre las angiospermas viarias? Especies de estudio: Angiospermas viarias nativas e introducidas. Sitio y años de estudio: Carretera Chalma-Malinalco, municipio de Malinalco, Estado de México, México, mayo 2008-abril 2009. Métodos: Se recolectaron las especies de angiospermas en el derecho de vía de la carretera a través de 24 recorridos quincenales. Adicionalmente, se enlistaron las especies y se estimó su cobertura en 14 cuadros de muestreo (4 m2 cada uno). Resultados: Se registraron 327 especies. Asteraceae, Fabaceae y Poaceae fueron las familias con mayor riqueza de géneros y especies. Las especies nativas fueron dominantes (85.9 %), mientras que las introducidas agruparon el 14.1 %; éstas últimas procedieron principalmente del Viejo Mundo. Alrededor del 70 % de las especies fueron hierbas. Bouteloua repens y Eleusine indica presentaron mayor cobertura y frecuencia, respectivamente. Conclusiones: La flora viaria era rica en angiospermas, la mayoría hierbas y con dominancia de plantas nativas. Los pastos introducidos tenían un papel sobresaliente en cuanto a frecuencia. Es necesario continuar con investigaciones florísticas, ecológicas, etnobotánicas, entre otras, sobre este grupo de plantas que ha sido escasamente estudiado.

Abstract Background: Research on weeds in rainfed maize crops in the state of Aguascalientes is scarce. Questions: What weed species are found in rainfed maize crops by biogeographic province? How are they controlled and managed? Study site and periods: One site in each of the three biogeographic provinces of the state of Aguascalientes: Sierra Madre Occidental (SMO), Altiplano Sur (AS) and Pacific Coast (CP), 2020 and 2021. Methods: Thirty semi-structured interviews were applied to describe the control and management of weeds. Forty-eight floristic inventories were carried out and the same number of sampling sites to obtain the richness and Shannon-Whiener and Simpson diversity indexes. Floristic similarity was evaluated with the Jaccard Index (I j). Results: Weed control is carried out mainly with tractor, animals and to a lesser extent herbicide. A total of 128 species were identified, 21 of which were introduced. SMO reported higher richness and diversity. There were not significant differences in average richness between the three provinces (P > 0.05) but there is a significant difference in diversity (H’) between SMO with AS and CP as well as (D Si) between CP and SMO (P < 0.05). Floristic similarity was less than 50 %. Conclusions: There is a great richness of weeds in rainfed maize crops. The floristic composition is differentiated by biogeographic province in the state of Aguascalientes. This work increases records and knowledge of weeds at local and national level.

Resumen Antecedentes: Las investigaciones sobre arvenses en cultivo de maíz de temporal en el estado de Aguascalientes son escasas. Preguntas: ¿Qué especies arvenses se encuentran en cultivos de maíz de temporal por provincia biogeográfica en el estado de Aguascalientes? ¿Cómo es su control y manejo? Sitio y años de estudio: Un sitio en cada una de las tres provincias biogeográficas del estado de Aguascalientes: Sierra Madre Occidental (SMO), Altiplano Sur (AS) y Costa del Pacífico (CP); durante los ciclos agrícolas 2020 y 2021. Métodos: Se aplicaron 30 entrevistas semiestructuradas para describir el control y manejo de arvenses. Se realizaron 48 inventarios florísticos y mismo número de muestreos para estimar riqueza e índices de diversidad de Shannon-Whiener (H’) y Simpson (D Si). La similitud florística se evaluó con el Índice de Jaccard (Ij). Resultados: El control de arvenses se realiza principalmente con tractor, yunta y en menor proporción herbicida. Se identificaron 128 especies, 21 introducidas. Aunque en SMO se registró mayor riqueza y diversidad, no existe diferencia significativa en la riqueza promedio entre las tres provincias (P > 0.05), pero sí en diversidad (H’) entre SMO con AS y CP y (D Si) entre CP y SMO (P < 0.05). La similitud florística fue menor al 50 %. Conclusiones: En el estado de Aguascalientes existe gran riqueza de arvenses en cultivos de maíz de temporal y la composición florística está diferenciada por provincia biogeográfica. Los resultados de la investigación suman al registro y conocimiento de las arvenses a nivel local y nacional.

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.

Resumen El herbicida tembotrione tiene un buen control de malezas y puede ser una herramienta importante en el cultivo del sorgo. Sin embargo, este herbicida está registrado en Brasil solo para maíz. Este estudio tuvo como objetivo evaluar la selectividad de la tembotrione asociada a la atrazine en diferentes dosis y etapas de desarrollo del grano de sorgo. Se realizaron dos experimentos en Rio Verde-GO y Montividiu-GO, Brasil en 2018. Se adoptó un diseño de bloques al azar con cuatro repeticiones, en un factorial 3x2+1+1, con tres etapas de desarrollo (V3, V5 y V7), dos dosis de tembotrione (37,8 y 75,6 g ha-1) asociada al herbicida atrazine (1,000 g ha-1), un tratamiento adicional con solo atrazine en V3 más un testigo sin herbicida. Los resultados permitieron observar síntomas visibles de fitotoxicidad cuando se aplicó la asociación entre los herbicidas tembotrione y atrazine en la etapa V3 y V5. Los síntomas incluyeron reducciones en la altura de la planta y el diámetro del tallo del sorgo y reducciones en la longitud de la panícula con la aplicación en la etapa V5. La aplicación de tembotrione en asociación con atrazine en V3 y V5 resultó en una reducción de la acumulación de masa seca en la parte aérea de las plantas de sorgo, pero sin influencia en la masa de mil granos, independientemente de la etapa de aplicación. El herbicida tembotrione en dosis de 37,8 g ha-1 en asociación con atrazine en dosis de 1,000 g ha-1 fue selectivo para sorgo en grano cuando se aplicó en V7, sin causar reducción en el rendimiento de grano.

Abstract The herbicide tembotrione is effective against grassy weeds constituting an important tool in sorghum crops. However, in Brazil, this herbicide is only registered for corn. This study aimed to evaluate the selectiveness of tembotrione combined with atrazine at different doses and developmental stages of grain sorghum. Two experiments were conducted in Rio Verde and Montividiu, state of Goiás, Brazil, in 2018. A randomized block design with four replications, in a 3x2+1+1 factorial arrangement, tested three developmental stages (V3, V5 and V7), two doses of tembotrione (37.8 and 75.6 g ha-1) combined with the herbicide atrazine (1,000 g ha-1), an additional treatment only with atrazine at V3 and a control, free of herbicide. Evident phytotoxicity was observed with the combination of tembotrione and atrazine at V3 and V5 stages. Symptoms included reductions in plant height, sorghum stem diameter, panicle length, and cumulative dry mass of sorghum plant shoots. However, there was no influence on thousand grains mass, regardless of application stages. Tembotrione at 37.8 g ha-1 combined with atrazine at 1,000 g ha-1 was selective for grain sorghum when applied at V7, without affecting grain yield.

Resumo A presença de plantas daninhas em áreas de atividades agrícolas é um entrave ao desenvolvimento dessas atividades. É importante aproveitar os vastos espaços abertos adequados para a agricultura e dar segurança alimentar para o homem. Também é um indicador importante para determinar a viabilidade de cultivo de lavouras, beneficiando-se da produtividade e determinando o percentual de perda, desmatando campos agrícolas, práticas que protegem as lavouras do ataque de ervas daninhas, e métodos de práticas agrícolas devem ser seguidos para reduzir a presença de ervas daninhas. Este estudo foi realizado durante os anos de 2018 a 2020 para avaliar Portulacaceae de flora na área de Taif, no Reino da Arábia Saudita, em diferentes altitudes (Área 1 = 1.700 m, Área 2 = 1.500 m, Área 3 = 1.500 m, Área 4 = 500 m, Área 5 = 2.200 m, e Área 6 = 2.200 m). Os resultados mostram que houve 2.816 indivíduos de planta daninha Portulaca oleracea, com a maior densidade encontrada em A 1, seguida de A 2, enquanto em A 5 e A 6, nas plantas daninhas foram registrados. A maior densidade de ervas daninhas estava nos campos de romã, seguido pelos campos de uva. A densidade mais baixa foi encontrada no campo A man. Os resultados deste estudo ajudarão a tomar as medidas necessárias para combater as ervas daninhas e seu manejo em áreas de atividade agrícola, enquanto mais estudos são necessários para levantar a ecologia das ervas daninhas de Taif na Arábia Saudita.

Abstract The presence of weeds in areas of agricultural activities is a hinderance to the development of these activities. It is important to take advantage of the vast open spaces suitable for agriculture and provide food security for humans, and also it is an important indicator for determining the feasibility of growing crops, benefiting from yield and determining the percentage of loss, clearing fields through agricultural practices, that protect crops from weed attack and agricultural practice method must be followed that will reduce weed presence. This study was conducted during the years 2018 to 2020 to evaluate Portulacaceae of Flora in the Taif area in the Kingdom of Saudi Arabia at different altitudes (Area 1 =1700 m, Area 2 =1500 m, Area 3 =1500 m, Area 4 =500 m ِ Area 5 = 2200 m, and Area 6 = 2200 m). The results show that there were 2,816 individuals of Portulaca oleracea weed, with the highest density found in A 1, followed by A 2, while in A 5 and A 6, no weeds were recorded. The highest density of weeds were in the Pomegranate fields, followed by Grape fields. The lowest density was found in A man field. The results of this study will help to take the necessary measures to combat weeds and its management in areas of agricultural activity, while more studies are needed to survey the ecology of weeds of Taif in The Kingdom of Saudi Arabia.

Resumo O estudo de pesquisa de campo foi realizado na temporada (2017). A soja e as ervas daninhas foram amostradas semanalmente de forma aleatória. Tripes adultos foram identificados e contados. A detecção do vírus isolado e a incidência natural foram determinadas usando transmissão mecânica, gama de hospedeiros, DAS-ELISA, RT-PCR. A incidência natural de tripes em indivíduos foi detectada dependendo da % de SVNV em tripes e hospedeiros infestantes. Dez espécies de tripes foram associadas a plantas de soja no campo. A espécie mais abundante foi T. tabaci, com média de 256,5 número médio de indivíduos, seguida por F. occidentalis (142,5) e N. variabilis (86,6 / número médio de indivíduos). Catorze espécies de tripes ocorreram em 5 culturas de leguminosas e 41 espécies de plantas daninhas dentro de campos de soja. O maior número médio de 40,6 indivíduos foi registrado em Ammi majus. Enquanto o mais baixo, 3,3 número médio de indivíduos, foi no Urtica urens. Apenas 21 espécies de plantas diagnosticadas foram suscetíveis à infecção com SVNV. G. max e Vigna radiate foram os maiores percentuais de infecção, 80%, seguidos por V. unguilata e N. benthamiana, 75%. O isolado egípcio neste estudo mostrou um alto grau de similaridade e está intimamente relacionado ao TSWV do Egito (DQ479968) e ao TCSV dos EUA (KY820965), com identidade de sequência de nucleotídeos de 78%. Quatro espécies de tripes transmitiram SVNV (F. fusca 4,0%, F. schultzei 4,3%, F. tritici 3,3% e N. variabilis 68,0% de transmissão). Tanto C. phaseoli quanto M. sjostedti podem adquirir o vírus, mas não podem transmiti-lo. As seguintes espécies, T. tabaci, F. occidentalis, S. dorsallis e T. palmi não podem adquirir ou transmitir SVNV. A incidência de SVNV no campo, iniciada no final de julho, aumentou gradativamente de 12,7 para 71,3% no final da temporada. Em conclusão, poucos indivíduos de tripes invadiram a cultura da soja e são suficientes para transmitir alta taxa de SVNV dentro da cultura. Além disso, várias espécies de vetores também abundam em ervas daninhas, que são as principais fontes dos vírus da soja transmitidos às lavouras. Essas informações podem ser importantes para controlar e reduzir a incidência de infecção por SVNV.

Abstract Field survey study was conducted season (2017). Soybeans and weeds were weekly sampled randomly. Thrips adults were identified and counted. Detection of the virus isolate and the natural incidence was determined using; Mechanical transmission, host range, DAS-ELISA, RT-PCR. The natural incidence thrips individuals was detected depending on the SVNV% in thrips individuals and weeds hosts. Ten thrips species were associated with soybean plants in the field. The most abundant species was T. tabaci, average 256.5 average no.of individuals, followed by F. occidentalis (142.5 average no. of individuals), then N. variabilis (86.6/ average no. of individuals). Fourteen thrips species occurred on 5 legumes field crops and 41 weed plant species within soybean field. The highest average number 40.6.of individuals were recorded on Ammi majus. While the lowest one 3.3 average no. of individuals were on Urtica urens. Only 21diagnostic plant species were susceptible to infection with SVNV. G. max and Vigna radiate, were the highest percentage of infection 80% followed by V. unguilata & N. benthamiana, 75%. Egyptian isolate of Soybean vein necrosis virus (SVNV) in this study showed a high degree of similarity and it is closely related to TSWV from Egypt (DQ479968) and TCSV from USA (KY820965) with nucleotide sequence identity of 78%. Four thrips species transmitted SVNV (F. fusca 4.0%, F. schultzei 4.3%, F. tritici 3.3% and N. variabilis 68.0% transmission). Both C. phaseoli and M. sjostedti can acquire the virus but unable to transmit it. The following species; T. tabaci, F. occidentalis, S. dorsallis and T. palmi cannot acquire or transmit SVNV. The incidence of SVNV in the field started by the end of July then increased gradualy from 12.7 to 71.3% by the end of the season. In conclusion, few thrips individuals invaded soybean crops are enough to transmit high rate of SVNV within the crop. Furthermore, several vector species are also abundant on weeds, which are the major sources of soybean viruses transmitted to the crops. This information might be important for control and reduce the incidence of SVNV infection.

Abstract The study considered the use of soil herbicides: Begin Turbo, KS; Dual Gold, KE; Euro-Lighting, VRK; Command, KE; Pivot, VK; Proponite, KE; Zenkor Ultra, KS and partially soil action: Demetra, KE, and Dialen Super, KS. We conducted a comparative assessment of the biological effectiveness of the studied herbicides against the main species of weeds present in the experimental plots, annual and perennial dicotyledonous, annual cereal weeds. The effect of soil herbicide treatments on the physiological state of plants of apple, pear, walnut, and black currant was studied. The effect of the use of the studied drugs on the yield of protected crops for three years was evaluated. The tests proved the applicability of soil herbicides in nursery, production gardens, as well as on seedlings with a closed root system. The tested products, despite the principle of their action - penetration into weeds through the soil, did not harm the protected crops, no negative effect on the growth of trees and shrubs was recorded. The study revealed no evidence that drugs had a negative impact on fruit and berry crop productivity. There are suggestions for improving the efficacy of using soil herbicides when planting fruit and berry crops. Turbo Gold KE EuroLighting, EuroLighting Euro Lighting, Lighting Euro-Lighting VRK Command Pivot VK Proponite Ultra Demetra Super plots dicotyledonous apple pear walnut evaluated nursery gardens system products recorded productivity

Resumo O estudo considerou o uso dos herbicidas de solo: Begin Turbo, KS; Dual Gold, KE; Euro-Lighting, VRK; Command, KE; Pivot, VK; Proponite, KE; Zenkor Ultra, KS e ação parcial do solo: Demetra, KE e Dialen Super, KS. Realizou-se uma avaliação comparativa da eficácia biológica dos herbicidas estudados contra as principais espécies de plantas daninhas presentes nas parcelas experimentais, dicotiledôneas anuais e perenes, plantas daninhas de cereais anuais. Estudou-se o efeito de tratamentos com herbicidas de solo sobre o estado fisiológico de plantas de macieira, pera, nogueira e groselha preta. Foi avaliado o efeito do uso das drogas estudadas na produtividade de cultivos protegidos por três anos. Os testes comprovaram a aplicabilidade de herbicidas de solo em viveiros, hortas de produção, bem como em mudas com sistema radicular fechado. Os produtos testados, apesar de seus princípios de ação - penetração em ervas daninhas através do solo, não prejudicou as culturas protegidas, não foi registrado nenhum efeito negativo no crescimento de árvores e arbustos. O estudo não revelou evidências de que as drogas tenham um impacto negativo na produtividade das frutas e bagas. Existem sugestões para melhorar a eficácia do uso de herbicidas de solo ao plantar frutas e bagas. Turbo Gold EuroLighting, EuroLighting Euro Lighting, Lighting Euro-Lighting VRK Command Pivot VK Proponite Ultra Demetra Super Realizouse Realizou se experimentais perenes Estudouse Estudou macieira pera preta anos viveiros produção fechado testados protegidas arbustos bagas

ABSTRACT: Carrier water quality is one of the main characteristics for an efficient and safe spraying of pesticides. Overall related to the levels of pH and hardness. The objective was to evaluate the interaction between water pH and storage time of the spray, containing 2,4-D amine, 2,4-D choline and dicamba, on the visible efficacy in Ipomoea triloba, Bidens pilosa, Amaranthus viridis; and water hardness on I. triloba. Three studies were carried out in a greenhouse. Study 1 with a 3x5 factorial, which factor A being pH of 2, 6 and 10 and factor B being 0, 2, 6, 24 and 36 hours of application after the mixture. Study 2 was a 3x5 factorial for each herbicide, whith factor A being the levels of pH (2, 6 and 10) and factor B being 0, 6, 12, 24 and 48 hours of application after the mixture. The study 3 is a 3x7 factorial, with factor A being the herbicides and factor B levels of water hardness: 0, 65, 125, 250, 500, 750 and 1000 parts per million. The pH of all solutions remained stable for 48 hours after preparation. However, did not interfere in efficacy of dicamba in I. triloba. Also, longer time between preparing the spray with 2,4-D formulations and application caused reduction efficacy on I. triloba. Also, the level of water hardness decreased control on I. triloba. The pH of carrier water did not affect efficacy of 2,4-D and dicamba on the weeds; however, longer time of the spray application reduce the visible efficacy. ABSTRACT pesticides 2,4D 24D D 2,4 4 amine triloba pilosa viridis I greenhouse x 3x 0 mixture herbicide (2 12 65 125 250 500 75 100 million preparation However Also weeds however 4D ( 25 50 7 5

RESUMO: A qualidade da água é uma das principais características para uma aplicação eficiente e segura de pesticidas. De maneira geral, a qualidade da água está relacionada aos níveis de pH e dureza. Assim, o objetivo foi avaliar a interação entre o pH da água e tempo de mistura da calda contendo os herbicidas 2,4-D amina, 2,4-D colina e dicamba, na eficácia visível em Ipomoea triloba, Bidens pilosa, Amaranthus viridis; além dos níveis de dureza da água em I. triloba. Três estudos feitos em estufa. Estudo 1 em fatorial 3x5 sendo o fator A pH de 2, 6 e 10 e o fator B 0, 2, 6, 24 e 26 horas da mistura até a aplicação. Estudo 2 em fatorial 3x5 para cada herbicida, sendo o fator A pH de 2, 6 e 10 e o fator B 0, 6, 12, 24 e 48 horas da mistura até a aplicação. Estudo 3 em fatorial 3x7 sendo o fator A os herbicidas e o fator B níveis de dureza da água: 0, 65, 125, 250, 500, 750 e 1000 partes por milhão. O pH manteve-se estável nas 48 horas. Entretanto, não interferiu na eficácia de dicamba em I. triloba. Além disso, maior tempo entre o preparo da calda com as formulações de 2,4-D e a aplicação causou redução da eficácia em I. triloba. Ainda, a dureza da água diminuiu o controle sobre I. triloba. O pH não afetou 2,4-D e dicamba sobre as plantas, entretanto, maior tempo de aplicação reduz a eficácia. RESUMO pesticidas geral Assim 2,4D 24D D 2,4 4 amina triloba pilosa viridis I estufa x 3x 0 herbicida 12 65 125 250 500 75 100 milhão mantevese manteve se Entretanto disso Ainda plantas entretanto 4D 25 50 7 5

ABSTRACT Sourgrass (Digitaria insularis) is one of the principal weeds in Brazil, and there are reports of its being glyphosate-resistant. The aim of this study was to determine the coexistence period of the TMG7063 IPRO soybean cultivar with a weed community predominated by D. Insularis, with no negative interference on final production (period prior to interference - PPI), as well as to determine the period for which the crop might remain free of such interference (total period of interference prevention) in Brazil. The coexistence and control periods under study were 15, 30, 45, 60, 75, 90, 105, and 120 days after sowing (DAS) the soybean, with the experiment arranged in a randomized block design with four replications. At the end of each coexistence period and at the end of the control-period experiment (single collection), there was an increase in weed density, dry matter, and the relative importance of D. insularis as the coexistence period increased. The number of pods was reduced from 87 (from 120 DAS in the control) to 49 (from 75 DAS for coexistence), and maximum yield was reduced from 5,551.3 kg ha-1 (from 120 DAS in the control) to 3,998.6 kg ha-1 (from 60 DAS for coexistence) due to coexistence with the weed community. The PPI was estimated at nine DAS, with losses of 5.0%. It can be concluded that a weed community predominated by D. insularis reduces soybean yield by up to 59.3%. The ‘TMG 7063 IPRO’ soybean can coexist with a weed community predominated by D. insularis for up to nine days after sowing and tolerate a loss in yield of up to 5%. Digitaria Brazil glyphosateresistant. glyphosateresistant glyphosate resistant. resistant glyphosate-resistant TMG TMG706 D Insularis PPI, , PPI) total prevention 15 30 45 90 105 12 (DAS replications controlperiod single collection, collection collection) density matter increased 8 4 7 coexistence, 55513 5 551 3 5,551. ha1 ha 1 ha- 39986 998 6 3,998. 50 0 5.0% 593 59 59.3% 706 5% TMG70 9 10 5551 55 5,551 3998 99 3,998 5.0 59.3 70 TMG7 555 5,55 399 3,99 5. 59. 5,5 39 3,9 5, 3,

ABSTRACT Gliricidia (Gliricidia sepium (Jacq) Kunth ex Walp) is a legume that has been used in agroforestry systems, for animal feed and contribution to soil fertility. During the cultivation of the crop, it is necessary to carry out weed management, as these can interfere with the growth and development of gliricidia, and it is essential to know the competitive ability of the crop with weeds. In view of the above, the objective was to evaluate the competitiveness of gliricidia coexisting with the weeds Senna obtusifolia(sicklepod), Commelina benghalensis(benghal dayflower), Bidens subalternans(beggarticks), Ipomoea triloba(morning glory) and Urochloa brizantha(signalgrass). The experiment was set up in a greenhouse, in a completely randomized design, with four replications. Each experimental unit consisted of a pot containing a gliricidia seedling in coexistence with three weeds of each species, in addition to the monoculture of the six species, as a comparison standard. The initial growth of gliricidia seedlings and weeds was evaluated through stem diameter, plant height, counting the number of leaves; root volume; and dry matter of leaves, stem and root. The data were submitted to analysis of variance (p<0.05) and when significant, the means were compared using the Tukey test. The competition of gliricidia with weeds resulted in a reduction in the increment of all analyzed variables. The results obtained showed that all weeds, with the exception of C. benghalensis, interfered negatively in the growth of the tree species. Jacq (Jacq Walp systems fertility management above obtusifoliasicklepod, obtusifoliasicklepod obtusifolia sicklepod , obtusifolia(sicklepod) benghalensisbenghal benghalensis benghal dayflower, dayflower dayflower) subalternansbeggarticks, subalternansbeggarticks subalternans beggarticks subalternans(beggarticks) trilobamorning triloba morning glory brizanthasignalgrass. brizanthasignalgrass brizantha signalgrass . brizantha(signalgrass) greenhouse design replications species standard diameter height leaves volume p<0.05 p005 p 0 05 (p<0.05 significant test variables C obtusifolia(sicklepod subalternans(beggarticks brizantha(signalgrass p<0.0 p00 (p<0.0 p<0. p0 (p<0. p<0 (p<0 p< (p< (p

RESUMO A gliricídia (Gliricidia sepium(Jacq) Kunth ex Walp) é uma leguminosa que vem sendo utilizada em sistemas agroflorestais, visando alimentação animal e contribuição na fertilidade do solo. Durante o seu cultivo é necessária a realização do manejo de plantas daninhas, pois essas podem interferir no crescimento e no desenvolvimento da gliricídia, sendo fundamental conhecer a habilidade competitiva da cultura com as plantas daninhas. Diante do exposto, este trabalho teve como objetivo avaliar a competitividade da gliricídia convivendo com as plantas daninhas Senna obtusifolia(fedegoso), Commelina benghalensis (trapoeraba), Bidens subalternans (picão-preto), Ipomoea triloba(corda-de-viola) e Urochloa brizantha(braquiária). O experimento foi montado em casa de vegetação, em delineamento inteiramente casualizado, com quatro repetições. Cada unidade experimental foi composta por um vaso contendo uma muda de gliricídia em convivência com três plantas daninhas de cada espécie, e o monocultivo das seis espécies, como padrão de comparação. Foi avaliado o crescimento inicial das mudas de gliricídia e das plantas daninhas através do diâmetro do caule, altura da planta e contagem do número de folhas; volume de raiz; massa da matéria seca das folhas, do caule e da raiz. Os dados foram submetidos à análise de variância (p<0,05) e quando significativas, as médias foram comparadas pelo teste de Tukey. A competição da gliricídia com as plantas daninhas resultou na redução de todas as variáveis analisadas. Os resultados obtidos comprovaram que todas as plantas daninhas, com exceção de C. benghalensis, interferiram negativamente no crescimento da espécie arbórea. Gliricidia sepiumJacq sepium Jacq sepium(Jacq Walp agroflorestais solo exposto obtusifoliafedegoso, obtusifoliafedegoso obtusifolia fedegoso , obtusifolia(fedegoso) trapoeraba, trapoeraba (trapoeraba) picãopreto, picãopreto picão preto (picão-preto) trilobacordadeviola triloba corda viola triloba(corda-de-viola brizanthabraquiária. brizanthabraquiária brizantha braquiária . brizantha(braquiária) vegetação casualizado repetições espécies comparação folhas raiz p<0,05 p005 p 0 05 (p<0,05 significativas Tukey analisadas C arbórea obtusifolia(fedegoso (trapoeraba (picão-preto brizantha(braquiária p<0,0 p00 (p<0,0 p<0, p0 (p<0, p<0 (p<0 p< (p< (p