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.

ABSTRACT. The grain production area in the Brazilian agricultural region known as SEALBA, especially in Alagoas State, has seen significant growth in recent years. This study aims to contribute to sustainable regional development by evaluating the effects of inoculation, co-inoculation, and the application of starter mineral nitrogen (N), either individually or in combination, on soybean growth and yield. Eight field experiments were conducted from 2018 to 2021 in two municipalities within Alagoas, covering soybean cultivation areas ranging from the first to the fourth year. The experiments followed a randomized complete block design with four replications, employing a factorial arrangement of treatments. The first factor encompassed five levels related to inoculation technologies and N management: 1) Inoculation with Bradyrhizobium; 2) Inoculation with Bradyrhizobium combined with N basal fertilization; 3) Co-inoculation of Bradyrhizobium + Azospirillum; 4) Co-inoculation of Bradyrhizobium + Azospirillum + N fertilization at the base; and 5) Control treatment without microbiological inputs or nitrogen fertilizers. The second factor involved the evaluation of different soybean cultivars, with two materials assessed in 2018 and three cultivars in 2019, 2020, and 2021. Results demonstrated that seed inoculation with Bradyrhizobium led to increased soybean grain yield in first-year cultivation areas. However, N basal fertilization, commonly known as starter fertilization, did not result in yield improvements compared to the use of microbiological inputs alone. Soybean cultivars BRS 9383 IPRO and FTR 3191 IPRO exhibited greater responsiveness to seed inoculation with Bradyrhizobium. ABSTRACT SEALBA State years coinoculation, coinoculation co co-inoculation N, , (N) combination 201 202 year replications treatments management 1 2 3 Coinoculation Co 4 base 5 fertilizers 2019 2020 firstyear However alone 938 319 (N 20 93 31 9

ABSTRACT The herbicide tembotrione may be seletivity to sorghum, which is of utmost importance in grain production systems. Thus, the present study aimed to evaluate the selectivity of tembotrione + atrazine combinations applied post-emergence at different phenological stages of grain sorghum. Four experiments were carried out in Rio Verde and Montividiu (state of Goiás) in succession to soybean cultivation in 2017 and 2018. The experiments were carried out in randomized block design with six replications, both in a (3x2) + 1 factorial arrangement. The first factor referred to three vegetative stages of application (V3, V5 and V7) associated with two doses of tembotrione (90 and 180 g ha-1) combined with atrazine (1,000 g ha-1)and and an additional treatment with no herbicide application. Tembotrione + atrazine applications at the V7 stage caused less damage to grain yield and dry mass accumulation in relation to V3 and V5. The dose of 90 g ha-1 tembotrione + atrazine combined with atrazine resulted in higher grain yields compared to 180 g ha-1, although still at lower levels compared to the treatment with no herbicides. Thus, herbicide tembotrione at doses of 90 and 180 g ha-1 combined with atrazine did not have selectivity for grain sorghum in applications at V3, V5 and V7 stages. systems Thus postemergence post emergence state Goiás 201 2018 replications 3x2 x (3x2 arrangement V (V3 (9 18 ha1 ha 1,000 1000 000 (1,00 ha1and haand 9 ha- ha1, 1, herbicides 20 3x (3x (V ( 1,00 100 00 (1,0 2 1,0 10 0 (1, (1

Resumen El mejoramiento genético de los cultivares de soja a lo largo de los años se ha centrado en aumentar la capacidad productiva y la tolerancia a algunos factores abióticos y bióticos. Sin embargo, durante la transferencia de genes de interés, algunos genes responsables de una menor tolerancia a los herbicidas pueden integrarse en el genoma del nuevo cultivar. El objetivo de este estudio fue evaluar la selectividad de las asociaciones de herbicidas apli cadas en la post-emergencia de tres cultivares de soja. El diseño experimental utilizado fue un bloque completamente al azar, con cuatro repeticiones. Los cultivares seleccionados fueron M7110 IPRO®, Foco IPRO® y Bônus IPRO®. Los herbicidas y las respectivas dosis (g a.i. ha-1) utilizados fueron: glyphosate (1176), glyphosate + bentazon (1176 + 600), glyphosate + fomesafen (1176 + 175), glyphosate + lactofen (1176 + 120), glyphosate + imazethapyr (1176 + 100), glyphosate + chlorimuron (1176 + 10), glyphosate + cloransulam (1176 + 39,5), y un control sin aplicación de herbicida. Se hizo una nota visual de intoxicación para cada tratamiento. Los componentes de crecimiento y rendimiento evaluados fueron: altura, rodal, peso de cien granos y rendimiento. La aplicación de herbicidas en post-emergencia no alteró la masa vegetal de los cultivares de soja. Además, estos herbicidas no redujeron el rendimiento de los cultivares M7110 IPRO® y Foco IPRO®. Tanto el glifosato aislado como mezclado con lactofen o imazethapyr redujeron el rendimiento del cultivar Bônus IPRO®.

Abstract The genetic improvement of soybean cultivars over the years has focused on increasing the yield potential and tolerance to some abiotic and biotic factors. However, during the transfer of genes of interest, some genes responsible for a lower tolerance to herbicides can be integrated into the genome of the new cultivar. Thus, the objective of this study was to evaluate the selectivity of herbicide associations applied in the postemergence period of three soybean cultivars. The experiment was conducted in a randomized completely block design, with four replications. The selected cultivars were M7110 IPRO®, Foco IPRO®, and Bônus IPRO®. The herbicides and the respective doses (g a.i. ha-1) used were glyphosate (1176), glyphosate + bentazon (1176 + 600), glyphosate + fomesafen (1176 + 175), glyphosate + lactofen (1176 + 120), glyphosate + imazethapyr (1176 + 100), glyphosate + chlorimuron (1176 + 10), glyphosate + cloransulam (1176 + 39.5), and a control without herbicide application. The visual note of intoxication was evaluated for each treatment. The components of growth and yield evaluated were height, stand, weight of one hundred grains, and yield. The application of postherbicide herbicides did not alter the plant stands of soybean cultivars. Additionally, these herbicides did not reduce the yield of the M7110 IPRO® and Foco IPRO® cultivars. Glyphosate isolated and in association with lactofen or imazethapyr reduced the grain yield of the Bônus IPRO® cultivar.

ABSTRACT Soil compaction negatively impacts soil physical functions, affecting root growth and crop yield. This study aimed to evaluate different soybean cultivars’ agronomic and physiological performance as a function of compaction in Rhodic Ferralsol under no-tillage (NT) with a clay loam texture in the Brazilian Cerrado biome. The experiment was implemented in Rio Verde, Goias state, central Brazil. The experimental design was a randomized block with a 3x2 factorial scheme with six replications. The first factor corresponded to three soybean cultivars from different maturity groups (MG) identified as super-early (MG = 6.2); early (MG = 6.8), and medium (MG = 7.9). The second factor was the cultivation in compacted and uncompacted soil. The experiment evaluated the soil physical properties: bulk density, total porosity, water content at matric potential -6 kPa, aeration capacity and water and air holding capacity in 0.0-0.1 and 0.1-0.2 m layers, agronomic and physiological traits (gas exchange). Soil compaction negatively affected the agronomic traits of soybean cultivars, with better performance of the medium cycle cultivar. Net photosynthesis, stomatal conductance, and transpiration rates were reduced up to 50% under compaction and were not influenced by cultivars. Our findings suggest that soil compaction negatively affected the performance of soybean cultivars with lower maturity groups reflecting in lower plant height, shoot and root dry mass, number of pods and grain yield. The choice of soybean cultivars with a longer cycle can be an alternative to minimize the adverse effects of soil compaction. functions yield notillage no tillage NT (NT biome Verde state Brazil x 3x replications MG superearly super 6.2 62 6 2 6.2) 6.8, 68 6.8 , 8 6.8) 7.9. 79 7.9 . 7 9 7.9) properties density porosity - kPa 0.00.1 0001 0.0 0.1 0 1 0.0-0. 0.10.2 0102 0.2 0.1-0. layers gas exchange. exchange exchange) cultivar photosynthesis conductance 50 height mass 6. 7. 00 0.00. 000 0. 01 0.0-0 10 0.10. 010 02 0.1-0 5 0.00 0.0- 0.10 0.1-

RESUMO O fungo causador da ferrugem asiática na soja, Phakopsora pachyrhizi, apresenta resistência cruzada e múltipla aos três grupos químicos (triazóis, estrobilurinas e carboxamidas) de fungicidas sítio-específicos. Este fato torna evidente a necessidade da implementação de estratégias para o manejo de prevenção da resistência. Uma alternativa pode ser a utilização de microrganismos com capacidade de interferir no desenvolvimento de patógenos, bem como atuarem como indutores da resistência das plantas. O objetivo do presente trabalho foi avaliar a eficácia de produto biológico à base de Bacillus subtilis BV02 isolado ou associado à produto à base de cobre no controle de ferrugem asiática, bem como desempenho agronômico da soja. Para tanto, foram instalados dois experimentos, sendo um no campo e outro em laboratório. Para o experimento conduzido em campo, o delineamento utilizado foi o de blocos ao acaso, estando os tratamentos dispostos em arranjo fatorial (5x2)+1, com quatro repetições. O primeiro fator correspondeu a aplicação, em pós-emergência da soja, de cinco doses de B. subtilis BV02 (0, 0,5, 1,0, 2,0 ou 4,0 L p.c. ha-1). O segundo fator correspondeu a associação ou não com produto à base de cobre. O tratamento adicional consistiu na aplicação da associação entre os fungicidas [azoxystrobina + benzovindiflupir] + mancozebe. No experimento em laboratório foi avaliada a germinação dos uredósporos de P. pachyrhizi em placas Elisa, no delineamento inteiramente casualizado com oito repetições. Foram utilizados os mesmos tratamentos do experimento do campo, diferenciando-se apenas o fungicida químico, o qual não foi adicionado mancozebe a calda aplicada. O aumento de dose de B. subtilis BV02, aplicado isoladamente, proporcionou reduções na severidade de ferrugem, não sendo visualizado este comportamento quando associado ao produto à base de cobre. Para a associação entre B. subtilis BV02 e produto à base de cobre, os melhores resultados para o controle de ferrugem asiática foram visualizados em doses iguais ou inferiores a 1,0 L p.c. ha-1. A produtividade da soja foi superior ao tratamento contendo fungicidas com a utilização de B. subtilis BV02 isolado (1,0 e 2,0 L p.c. ha-1), com aplicação apenas de produto à base de cobre e com utilização deste micronutriente em associação ao B. subtilis BV02 (2,0 L p.c. ha-1). triazóis, triazóis (triazóis carboxamidas sítioespecíficos. sítioespecíficos sítio específicos. específicos sítio-específicos patógenos plantas BV BV0 tanto experimentos acaso 5x2+1, 5x21 x 5x2 +1, 1 (5x2)+1 repetições pósemergência pós emergência B 0, 0 (0 05 5 0,5 10 20 2 2, 40 4 4, pc p c p.c ha1. ha1 ha . ha-1) azoxystrobina benzovindiflupir P Elisa diferenciandose diferenciando se químico aplicada isoladamente 1, 1. ha-1 (1, ha1, , (2, 5x2+1 5x +1 (5x2)+ ( ha- (1 (2 5x2+ (5x2) (5x2 (5x

ABSTRACT The fungus that causes Asian soybean rust, Phakopsora pachyrhizi, shows crossed and multiple resistance to the three chemical groups of site-specific fungicides (triazoles, strobilurins and carboxamides). This fact evidences the need to implement strategies for the preventive management of resistance. An alternative can be the use of microorganisms capable of interfering in the development of pathogens, as well as of acting as resistance inducers in the plants. The objective of the present study was to evaluate the efficacy of a biological product based on Bacillus subtilis BV02, alone or in association with a copper-based product, on Asian soybean rust control, as well as the agronomic performance of soybean. Thus, two experiments were developed, one in the field and another one in the laboratory. For the experiment conducted in the field, a randomized block design was used with (5x2)+1 factorial arrangement of treatments, including four replicates. The first factor corresponded to application, during post-emergence of soybeans, of five B. subtilis BV02 doses (0, 0.5, 1.0, 2.0 or 4.0 L c.p. ha-1). The second factor corresponded to association or not with a copper-based product. The additional treatment consisted of applying the fungicide association [azoxystrobin + benzovindiflupyr] + mancozeb. In the laboratory experiment, germination of Phakopsora pachyrhizi uredospores in Elisa plates was evaluated in a completely randomized design with eight replicates. Treatments were the same as those adopted in the field experiment, except for the chemical fungicide, since mancozeb was not added to the sprayed broth. Increasing doses of B. subtilis BV02, applied alone, provided reductions in Asian soybean rust severity, and this behavior was not observed when it was applied in association with the copper-based product. Considering the association between B. subtilis BV02 and the copper-based product, the best Asian rust control results were found with doses equal or inferior to 1.0 L c.p. ha-1. Soybean yield was superior to that of the treatment containing fungicides with the use of B. subtilis BV02 alone (1.0 and 2.0 L c.p. ha-1), with application of only a copper-based product and with the combination of this micronutrient with B. subtilis BV02 (2.0 L c.p. ha-1). sitespecific site specific triazoles, triazoles (triazoles carboxamides. carboxamides . carboxamides) pathogens plants BV copperbased copper Thus developed 5x2+1 5x21 x 5x2 +1 1 (5x2)+ treatments replicates postemergence post emergence soybeans B BV0 0, 0 (0 05 5 0.5 10 20 2 2. 40 4 4. cp c p c.p ha1. ha1 ha ha-1) azoxystrobin benzovindiflupyr broth severity 1. ha-1 (1. ha1, , (2. 5x2+ 5x (5x2) ( 0. ha- (1 (2 (5x2 (5x

RESUMEN El espaciamiento entre hileras comúnmente utilizado en el cultivo de yuca en Brasil, especialmente en la región de Agreste de Alagoas, varía de 100 a 120cm. Sin embargo, la reducción del espacio entre hileras puede promover ganancias agronómicas y ambientales en los sistemas de cultivo con yuca. Por lo tanto, el objetivo de este trabajo fue evaluar el comportamiento de dos variedades de yuca cultivadas con espaciamiento reducido entre hileras. Se realizaron dos experimentos en el campo, uno en el 2015/16 y otro en el 2017/18. El diseño experimental utilizado en ambos experimentos fue el de Parcelas Divididas con cuatro repeticiones. Se evaluaron cuatro espaciamientos entre filas en la parcela principal: 60, 80, 100 y 120cm, con plantas espaciadas 60cm dentro de las hileras, dando poblaciones de 27,778, 20,833, 16,667 y 13,889 plantas por hectárea, respectivamente. En las subparcelas se evaluaron dos variedades de yuca: Caravela y Pretinha. Un aumento en el espaciamiento entre hileras promovió una reducción lineal en la masa verde del tallo de la yuca. La altura de la planta, la masa verde de la hoja, el diámetro del tallo principal, el rendimiento de la raíz, la longitud de la raíz tuberosa, el diámetro de la raíz tuberosa, el porcentaje de harina, el rendimiento de la harina y el contenido de almidón no se vieron afectados por los cambios en el espaciamiento entre hileras. La variedad Pretinha fue superior a Caravela en las siguientes características evaluadas: masa verde del tallo, diámetro de raíces tuberosas, rendimiento de raíces, altura de planta y rendimiento de harina. Los resultados indican la posibilidad de alterar el espaciamiento entre hileras en la yuca para ayudar en el manejo cultural, sin afectar el rendimiento del cultivo.

ABSTRACT The interrow spacing commonly used in cassava cultivation in Brazil, especially in the Agreste region of Alagoas, ranges from 100 to 120cm. However, the reduction in row spacing can provide agronomic and environmental benefits in cassava cropping systems. Thus, this work aimed to evaluate the performance of two cassava varieties cultivated with reduced interrow spacing. Two experiments were conducted in the field, one in 2015/16 and another in 2017/18. A Split Plot design with four replications was used in both experiments. Four interrow spacing were evaluated in the main plot: 60, 80, 100 and 120cm, with plants spaced 60cm apart within rows, giving populations of 27,778, 20,833, 16,667 and 13,889 plants per hectare, respectively. In the subplots, two cassava varieties were evaluated: Caravela and Pretinha. An increase in interrow spacing promoted a linear reduction in the stem green mass of cassava. Plant height, leaf green mass, main stem diameter, root yield, tuberous root length, tuberous root diameter, flour percentage, flour yield, and starch content were not influenced by changes in interrow spacing. The Pretinha variety was superior to Caravela in the following evaluated traits: stem green mass, the diameter of tuberous roots, root yield, plant height, and flour yield. The results indicate the possibility of altering the interrow spacing in cassava to assist in the cultural management, without impacting crop yield.

ABSTRACT. The succession of soybean/maize has been largely adopted. Storm damage and crop problems can lead to grain loss, generating maize ear fragments or even whole ears that remain in the soil and still display germination viability, resulting in the occurrence of volunteer plants. In this context, the present study aimed to evaluate the interference of voluntary maize plants on soybean and investigate the susceptibility of maize hybrids to pre-emergence herbicides. In the first step, an experiment was performed evaluating the influence of voluntary maize plant density and spatial distribution on soybean. The experiment was performed in a randomized completely block design (RCBD) with four replications, with treatments disposed in factorial arrangement (2 x 4) + 1. The first factor corresponded to the spatial distribution of maize plants: row or in between soybean rows; while the second factor adopted four infestation densities of maize plants m-2: 4, 8, 12, and 16. The additional treatment consisted of a control without maize plants. For the second step, an experiment was conducted in two locations aiming to determine the efficacy of pre-emergence herbicides in the control of voluntary maize. Both experiments were installed in RCBD in a split-plot scheme with four replications. Fomesafen, lactofen, sulfentrazone, chlorimuron-ethyl, diclosulam, flumetsulam, imazethapyr, clomazone, metribuzin, [sulfentrazone + diuron], [imazethapyr + flumioxazin], and a control without herbicide application were evaluated in the main plot. In each subplot, the maize hybrids DKB310 PRO3™ and DKB390 PRO3™ were evaluated. No influence on the position of voluntary maize on the soybean yield was observed. The presence of the maize population led to a progressive decrease in soybean yield, ranging up to 86%, at 16 plants m-2. DKB390 displayed a stand reduction of 82.88% after the use of diclosulam. Diclosulam led to better results regarding maize plant decreases for both hybrids.

RESUMO Entre as espécies que tem causado maiores prejuízos nos sistemas brasileiros de produção de soja, está o capim-amargoso. Neste contexto, o objetivo deste trabalho foi avaliar o efeito da interferência do capimamargoso na soja cultivada em condições de Cerrado. Para tanto, foram instalados três experimentos à campo, sendo dois simulando área com falhas na dessecação de capim-amargoso na pré-semeadura da soja, com plantas remanescentes desta espécie (E1 e E2) e um no qual simulou a emergência do capim-amargoso ocorreu de forma simultânea a da soja (E3). No E1 e E2, o delineamento utilizado foi o de blocos casualizados (DBC), sendo avaliados cinco tratamentos compostos por densidades crescentes de capim-amargoso (0, 2, 4, 6 e 8 plantas por m2) e quatro repetições. No E3, também foi utilizado o DBC, estando os tratamentos dispostos em arranjo fatorial 2 x 5, com quatro repetições. O primeiro fator foi composto de duas cultivares de soja de ciclo distinto; enquanto que no segundo foram simuladas densidades de capim-amargoso em convivência com a soja, sendo adotadas as mesmas do E1 e E2. O aumento de densidade de capim-amargoso em convivência com a soja proporciona redução na produtividade da cultura, independentemente se estas plantas estavam emergidas na ocasião da semeadura ou se a infestação foi estabelecida após a emergência da soja. A intensidade de redução na produtividade da cultura é maior quando as plantas de capim-amargoso já se encontram entouceiradas na área na ocasião da semeadura da soja, chegando a reduções próximas de 80% na maior densidade de infestação.

ABSTRACT Sourgrass (Digitaria insularis) is one of the main species causing significant losses in Brazilian soybean production systems. Thus, this paper aimed to evaluate sourgrass interference on soybeans grown under Cerrado conditions. Three field experiments were conducted, of which the first two (E1 and E2) simulated sourgrass after pre-sowing burndown, using plants already emerged by the time soybeans were sown; whereas the third (E3) simulated both sourgrass and soybeans emerged simultaneously. Both E1 and E2 were conducted in a randomized complete block design (RCBD) with five treatments based on sourgrass infestation densities (0, 2, 4, 6, and 8 plants m-2) and four replications. In turn, E3 was also carried out in an RCBD but with treatments arranged in a 2 x 5 factorial and four replications. The first factor comprised two soybean cultivars, while the second was sourgrass density levels, just as in E1 and E2. The results showed that increasing sourgrass densities reduced soybean yield regardless of the plant growth stage when the crop was sown. Yield losses were higher when sourgrass plants were already established by the time soybean was sown. Soybean yield losses reached up to 80% under higher sourgrass infestation levels.

RESUMO Danos causados por doenças que ocorrem durante os estádios vegetativos no milho resultam em redução do rendimento de grãos, e o controle químico é uma das estratégias que possibilita a redução dos danos. O objetivo desse trabalho foi quantificar o dano em milho em função da redução da área foliar causada pelo complexo de doenças, associando ou não a remoção de folhas em diferentes posições da planta. O experimento foi conduzido no campo, no delineamento de blocos casualizados com quatro repetições e tratamentos dispostos em arranjo fatorial 10 x 3. O primeiro fator correspondeu a associação de dois fungicidas em diferentes doses, combinados com desfolhas artificiais realizadas nas plantas no momento da primeira aplicação. O segundo fator consistiu em diferentes estádios de aplicação (VT, R1 e R2). O híbrido utilizado foi o Fórmula TL®, suscetível à cercosporiose, ferrugem polissora e mancha-branca. Foi avaliado o progresso das doenças, índice de área foliar e o rendimentos de grãos. Aplicações preventivas (estádio fenológico VT) de fungicidas, independentemente da remoção de folhas na planta, proporcionou menor progresso das doenças e menores danos. Maiores valores significativo de massa de grãos e produtividade foram obtidos com uso de fungicidas sem a remoção de folhas, independentemente do estádio fenológico da aplicação.

ABSTRACT Damage caused by diseases that occur during the vegetative stages of corn results in decreased grain yield, and chemical control is one of the strategies to allow damage reduction. The objective of this study was to quantify the damage to corn plants as a function of leaf area reduction caused by the disease complex, associated or not with leaf removal from different positions in the plant. The experiment was carried out in the field, in a completely randomized block design with four replicates and 10 x 3 factorial arrangement of treatments. The first factor corresponded to the association of two fungicides at different doses, combined with artificial defoliation at the first fungicide spraying. The second factor consisted of application at different stages (VT, R1 and R2). The used hybrid was Formula TL®, which is susceptible to cercosporiosis, polysora rust and white spot. Disease progress, leaf area index and grain yield were evaluated. Preventive application of fungicides (phenological stage VT), regardless of leaf removal from the plant, provided less disease progress and less damage. Higher significant values of grain mass and yield were obtained with fungicide application without leaf removal, regardless of the phenological stage receiving the application.

RESUMO As áreas de cultivo de cana-de-açúcar apresentam em sua maioria, baixa fertilidade do solo e, elevada demanda por nutrientes, especialmente o nitrogênio. Tecnologias que possam contribuir com o aumento de produtividade, aliado ao menor uso de defensivos e fertilizantes estão entre as principais necessidades da cultura. Objetivou-se avaliar o desempenho agronômico da cana-de-açúcar após a aplicação em sulco de plantio da bactéria diazotrófica Nitrospirillum amazonense (BR11145). Os tratamentos foram compostos pela aplicação no sulco de plantio de cinco doses de produto à base de N. amazonense: 0,25, 0,5, 1,0, 1,5 e 2,0 L p.c. ha-1, um tratamento composto pela associação entre as bactérias Bacillus subtilis e Bacillus licheniformis, além uma testemunha sem adubação e outra com adubação. Com base nos resultados obtidos da análise conjunta de dois experimentos, pode-se afirmar que: o produto à base de N. amazonense proporciona melhorias nos parâmetros de crescimento das plantas de cana-de-açúcar, sendo que, nas doses de 1,0 e 1.5 L p.c. ha-1, estes benefícios resultaram em aumento significativo de produtividade e na quantidade de açúcar por hectare. A inoculação de bactérias diazotróficas representa um benefício para a cana-de-açúcar, especialmente por favorecer o crescimento e a produtividade da cultura similarmente à utilização de fertilizantes.

ABSTRACT Sugarcane cultivation areas are usually characterized by low soil fertility and high nutrient demand, especially for nitrogen. Technologies that can raise crop yield and lower the use of pesticides and fertilizers are among the main needs of this crop. The objective of this study was to evaluate the agronomic performance of sugarcane after in-furrow application of the diazotrophic bacterium Nitrospirillum amazonense (BR11145). The treatments consisted of applying five doses of N. amazonense-based product to the planting furrow, 0.25, 0.5, 1.0, 1.5, and 2.0 L commercial product (c.p.) ha-1; a treatment consisting of the combination of Bacillus subtilis and Bacillus licheniformis; one control without fertilization; and one control with fertilization. Based on the results obtained from the pooled analysis of two field experiments, the N. amazonense-based product improved the growth parameters of sugarcane plants, and at doses of 1.0 and 1.5 L c.p. ha-1, these benefits resulted in a significant increase in yield and in the amount of sugar per hectare. Inoculation with diazotrophic bacteria can benefit sugarcane, especially because it promotes the growth and yield of the crop similarly to fertilizers.

ABSTRACT Weed management consists of a fundamental practice in cassava, with mechanical and chemical control widely used. The objective of this work was to evaluate the efficacy of pre-emergence herbicides, as well as to determine the interaction of these with weeding complementation in the weed management in cassava. Two experiments were conducted in Junqueiro (Alagoas). In 2015/16, the experimental design was based on randomized blocks, with treatments distributed in a split-split-plot scheme, with four replications. In the main plot, four pre-emergence associations of clomazone + flumioxazin in different doses were evaluated, in addition to a control without herbicide. In the subplots, the Caravela and Pretinha cassava cultivars were evaluated, while in the sub-subplots the control complementation was evaluated using or not the manual weeding. In the 2016/17, the plot design and layout remained the same as for 2015/16, except for the composition of the herbicide treatments, since the standardization of clomazone dose has been chosen, varying only the doses of flumioxazin. The association of clomazone and flumioxazin has shown efficacy in weed control, with a greater residual as higher doses are used. This association provided higher shoot and root yield. Weeding complementation along the cassava cycle can increase its yield.

RESUMO A disposição espacial em que plantas se encontram na área de cultivo é fator que influencia diretamente na produtividade de grãos, pois o melhor arranjo entre essas pode resultar em maior aproveitamento de água, luz e nutrientes. O objetivo do trabalho foi avaliar o desempenho agronômico de sorgo semeado em espaçamento de fileiras duplas no Cerrado. Para tanto, foi conduzido nas safrinhas de 2018 e 2019, experimentos de campo em delineamento de blocos completos em esquema fatorial 2 x 5, com quatro repetições, em que se utilizou dois espaçamentos de entrelinhas de semeadura: tradicional (0,50 m) e fileiras duplas (0,25 m/0,75 m) e cinco populações de plantas: 120, 180 (recomendada), 240, 300 e 360 mil plantas ha-1. Foram avaliadas características morfológicas, componentes do rendimento e produtividade de grãos utilizando análise conjunta dos dados para os dois anos de estudo. Em 2018, devido ao menor volume de chuvas durante o ciclo da cultura, a utilização do arranjo em fileiras duplas apresentou produtividade de grãos inferior ao espaçamento tradicional. Por outro lado, em 2019, ano com melhor distribuição hídrica, a produtividade foi superior a 2018. O aumento da população de plantas por hectare incrementou a produtividade de grãos de sorgo, com ganhos de até 24% em relação à população recomendada de 180 mil plantas ha-1, demonstrando que o adensamento nessa cultura pode ser uma técnica promissora desde que levado em consideração seu custo/benefício.

ABSTRACT The spatial arrangement of plants in the cultivation area is a factor that directly influences grain yield, since the best arrangement can result in the greater use of water, light and nutrients. The aim of the study was to evaluate the agronomic performance of sorghum sown in double row spacing in the Brazilian Cerrado. For this purpose, field experiments were conducted in the 2018 and 2019 seasons in a complete block design with a factorial scheme of 2 x 5. There were four replications, using two row spacing: traditional (0.50 m) and double rows (0.25 m/0.75 m) and five plant populations: 120, 180 (recommended), 240, 300 and 360 thousand, plants ha-1. Morphological characteristics, yield components and grain yield were evaluated using joint data analysis for the two years of study. In 2018, due to lower rainfall during the crop season, the use of a double row arrangement presented grain yield lower than traditional spacing. On the other hand, in 2019, the year with the best water distribution, the yield was superior to that of 2018. The increase in plant population per hectare increased the yield of sorghum grains, with gains of up to 24% in relation to the recommended population of 180 thousand plants ha-1, demonstrated that the densification in this crop can be a promising technique as long as its cost/benefit is considered.

RESUMO O glyphosate é o principal herbicida utilizado no controle de plantas daninhas na cultura da soja Roundup Ready® (RR®), entretanto os diferentes sais e formulações do herbicida disponíveis no mercado podem ocasionar fitointoxicação. Neste cenário, os bioestimulantes surgem como alternativa promissora para mitigar os possíveis efeitos fitotóxicos do glyphosate. Sendo assim, objetivo do trabalho foi avaliar o efeito de doses do bioestimulante MC Extra® associado as formulações de glyphosate nas características agronômicas da cultura da soja tolerante ao herbicida. Conduziram-se dois experimentos nas safras 2015/16 e 2016/17 adotando-se três doses do MC Extra® (0.35; 0.70 e 1.00 kg ha-1) associadas a seis formulações de glyphosate: Glyphotal®, Roundup Original®, Roundup Ready®, Roundup WG®, Roundup Transorb® e Zapp QI®, além de um tratamento adicional sem o uso do herbicida. Em ambos os experimentos foi padronizado o uso da dose de 900 g e. a. ha-1 de glyphosate. Os resultados demonstraram que a maior dose do MC Extra®, em associação às formulações Roundup Original®, Roundup Ready® e Roundup Transorb® e 0.70 kg ha-1 de MC Extra® com Glyphotal® foram as que proporcionaram as maiores produtividades de grãos. Quando usado em conjunto com o herbicida, há a necessidade de aumento da dose do MC Extra® para se ter maiores produtividades de grãos da soja.

ABSTRACT Glyphosate is the main herbicide used in the Roundup Ready® (RR®) soybean crop. However, the different salt and herbicide formulations available on the market can lead to crop intoxication. In this scenario, biostimulants appear as a promising alternative to mitigate the possible phytotoxic effects of glyphosate. Thus, the objective of this work was to evaluate the effects of different MC Extra® biostimulant doses associated with glyphosate formulations on the agronomic characteristics of a herbicide-tolerant soybean cultivar. Two experiments were conducted in the 2015/16 and 2016/17 seasons with three doses of MC Extra® (0.35, 0.70, and 1.00 kg ha-1) associated with six formulations of glyphosate: Glyphotal®, Roundup Original®, Roundup Ready®, Roundup WG®, Roundup Transorb®, and Zapp QI®, plus additional treatment without the use of the herbicide. In both experiments, we used 900 g e.a. ha-1 of glyphosate. The results showed that the highest dose of MC Extra®, in combination with the Roundup Original®, Roundup Ready®, and Roundup Transorb® formulations and 0,70 kg ha-1 of MC Extra® with Glyphotal® provided the highest grain yields. When used in conjunction with the herbicide, there is a need to increase the dose of MC Extra® to obtain higher soybean yields.

RESUMO Com o advento da soja resistente ao glifosato, aplicações em pós-emergência da cultura tornaram-se corriqueiras. Dessa forma, problemas relacionados à seletividade desse herbicida mostraram-se cada vez mais intensos, devido ao aumento da dose utilizada e à aplicação em momentos não recomendados. Para avaliar o desempenho agronômico da soja submetida à aplicação de glifosato isolado em pós-emergência e em associação ao Crop+ em diferentes estádios e doses, um experimento foi realizado em delineamento de blocos ao acaso, em esquema de testemunhas duplas adjacentes, adotando-se quatro repetições. Os tratamentos foram constituídos por: glifosato (1296 g·ha-1); glifosato + Crop+ (1296 + 0,25 g ou L·ha-1); glifosato + Crop+ (1296 + 0,5 g ou L·ha-1);glifosato (2592 g·ha-1); glifosato + Crop+ (2592 + 0,25 g ou L·ha-1);glifosato + Crop+ (2592 + 0,5 g ou L·ha-1); 2 × glifosato (2 × 1296 g·ha-1); 2 × glifosato + Crop+ (2 × 1296 + 0,25 g ou L·ha-1); 2 × glifosato + Crop+ (2 × 1296 + 0,5 g ou L·ha-1) e Crop+ (0,5 g·ha-1). Foram avaliados fitointoxicação das plantas de soja, índice SPAD (soil plant analysis development), altura, estande, massa de cem grãos e produtividade. Nos resultados, a utilização de Crop+ em plantas de soja proporcionou o aumento no índice SPAD e, quando o Crop+ foi associado ao glifosato, possibilitou a atenuação dos sintomas visuais de injúrias, prevenindo reduções na produtividade da cultura.

ABSTRACT With the advent of glyphosate-resistant soybean, postemergence applications of the herbicide have become routine. In this way, problems related to the selectivity of glyphosate have been shown to be increasingly intense, due to the use of increased dosages and applications of the herbicide at unrecommended moments. In order to evaluate the agronomic performance of soybean plants subjected to the postemergence application of glyphosate – both in isolation and together with Crop+ – at different stages and dosage levels, a randomized block design experiment was carried out with two adjacent checks and four repetitions. The treatments consisted of: glyphosate (1296 g·ha-1); glyphosate + Crop+ (1296 + 0.25 g or L·ha-1); glyphosate + Crop+ (1296 + 0.5 g or L·ha-1); glyphosate (2592 g·ha-1); glyphosate + Crop+ (2592 + 0.25 g or L·ha-1); glyphosate + Crop+ (2592 + 0.5 g or L·ha-1); 2 × glyphosate (2 × 1296 g·ha-1); 2 × glyphosate + Crop+ (2 × 1296 + 0.25 g or L·ha-1); 2 × glyphosate + Crop+ (2 × 1296 + 0.5 g or L·ha-1) and Crop+ (0.5 g·ha-1). The phytotoxicity, soil plant analysis development (SPAD) index, height, stand, mass of 100 grains, and yield of the soybean plants were evaluated. The use of Crop+ on soybean plants led to an increase in the SPAD index; the use of Crop+ in association with glyphosate made possible the attenuation of visible symptoms of damage, preventing reductions in crop yield.