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 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

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-

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 Com a expansão do plantio de sorgo como cultura de sucessão na segunda safra, os programas de melhoramento precisam ampliar a criação de novas linhagens, visando à produção de híbridos de alto desempenho. O primeiro passo para o processo de seleção consiste na avaliação do desempenho per se das linhagens ou de suas combinações híbridas. O presente trabalho objetivou estimar a capacidade combinatória de linhagens de sorgo granífero em diferentes condições ambientais em plantios na segunda safra. Os ensaios foram conduzidos em sistema de plantio direto, em quatro ambientes: Rio Verde, Sete Lagoas, Teresina e Sinop. Foram avaliados trinta híbridos resultantes dos cruzamentos de seis linhagens restauradoras da fertilidade (R) com cinco linhagens macho-estéreis (A). Foi empregado o delineamento experimental em blocos casualizados, com três repetições. As características avaliadas foram dias para o florescimento, altura das plantas e produtividade de grãos. O ambiente influenciou significativamente nas estimativas de capacidade geral e específica de combinação, e estas sugerem haver importância dos efeitos aditivos e dominantes no controle desses caracteres. As linhagens restauradoras GI.1 e G1.2 contribuíram para aumentar a produtividade de seus híbridos em mais 650 kg.ha-1. Entre as linhagens macho estéreis as melhores para rendimento de grãos foram GII.1 e GII.4 com contribuição acima de 450 kg.ha-1 nos híbridos em que participaram. As combinações híbridas GI.5xGII.3 e GI.1xGII.2 se destacaram por apresentarem potencial de obterem médias altas de produtividade de grãos, associando aspectos favoráveis de dias para o florescimento e altura das plantas.

ABSTRACT The expansion of sorghum as a succession crop, after soybean, has demanded the development of new inbred lines by the breeding programs. The first step in the selection process consists of evaluating the performance per se of the inbred lines or of their hybrid combination. The purpose of this study was to determine the combining ability of sorghum inbred lines under different environment conditions of the crop production areas. The trials were carried out in the second season of 2017, under no-tillage system, in four environments, Rio Verde, Sete Lagoas, Teresina and Sinop. Thirty hybrids, resulting from the crosses of six fertility restoration lines (R) with five male-sterile lines (A) were evaluated. A randomized complete block design with three replicates was used in all experiments. The characteristics evaluated were flowering, plant height and grain yield. The environment significantly influenced the estimates of general and specific combining ability, which suggests that both effects, additive and dominant, are important in the control of these characters. The restoring lines GI.1 and G1.2 contributed to increasing the grain yield of their hybrids by over 650 kg.ha-1. Among the male-sterile lines, the best for grain yield were GII. 1 and GII.4 with contribution above 450 kg.ha-1 in the hybrids in which they participate. The hybrid combinations GI.5xGII.3 and GI.1xGII.2 stood out with potential to obtain high grain yield, associating positive aspects of the other characteristics.

ABSTRACT The use of no-till conservationist agricultural systems as well as intercropping in the Cerrado biome are practices that increase soil organic matter (SOM) due to the deposition of straw. This study aimed to quantify the carbon stock and organic fractions of a latosol under off-season monoculture (Sorghum bicolor and Urochloa ruziziensis) and intercropping (S. bicolor-U. ruziziensis) systems, in Rio Verde, state of Goiás, Brazil. Soil samples were collected from different layers: 0-10, 10-20 and 20-40 cm. The following variables were determined: organic carbon content, carbon stock, dry matter and fractions of organic matter (labile and mineral). The results showed that the organic fractions of the soil are modified according to the adopted management. Intercropping of S. bicolor and U. ruziziensis increased the carbon stock, with the presence of more labile organic fractions on the soil surface, while the use of U. ruziziensis enhances the production of recalcitrant organic fractions, promoting greater preservation of the soil organic matter.

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 O consórcio de sorgo granífero com braquiária proporciona a produção de grãos e massa seca na entressafra; contudo, há carência de informações relacionadas à implantação dessas espécies. Sendo assim, este trabalho teve por objetivo identificar a melhor associação de sorgo granífero e braquiária na segunda safra para produção de grãos e massa seca na região do Cerrado. O experimento foi conduzido em Rio Verde, Goiás, no delineamento experimental de blocos randomizados, em esquema fatorial 2×3×4+5, com quatro repetições. Foram avaliados dois híbridos de sorgo granífero (BRS 330 e DKB 551) associados a três espécies de Brachiaria (Brachiaria brizantha cultivar Marandu, Brachiaria decumbens e Brachiaria ruziziensis) em quatro sistemas de implantação da braquiária (linha, entrelinha, linha + entrelinha do sorgo e a lanço). Os tratamentos adicionais referiam-se aos dois monocultivos de sorgo e às três espécies de braquiária. O consórcio de sorgo com braquiária ocasionou redução no rendimento de grãos, porém os sistemas de implantação da braquiária na linha, entrelinha e a lanço foram os mais promissores. O híbrido de sorgo DKB 551 foi o mais sensível à competição com a braquiária, sem, contudo, haver diferenças de rendimento de grãos em consórcio. Os consórcios das braquiárias na entrelinha e na linha + entrelinha, principalmente com a B. ruziziensis, foram os mais promissores para produção de massa seca e proteína bruta total. O cultivo de braquiária com o sorgo proporcionou maior aporte de massa seca na entressafra, fato importante para o sistema de plantio direto nos sistemas de produção agrícola dos Cerrados.

ABSTRACT The grain sorghum intercropped with Brachiaria provides the production of grains and dry mass in the off-season; however, there is a lack of information related to the implantation of these species. The objective of this study was to identify the best association of sorghum and Brachiaria in the production of grain and dry matter in the Brazilian Cerrado region. The experiment was conducted in Rio Verde, State of Goiás, in the experimental design of randomized blocks, in a 2×3×4+5 factorial scheme, with four replications. Two sorghum hybrids (BRS 330 and DKB 551) associated to three Brachiaria species (Brachiaria brizantha cultivar Marandu, Brachiaria decumbens and Brachiaria ruziziensis) were evaluated in four systems of Brachiaria implantation (row, interrow, row + interrow of sorghum and spread). Additional treatments referred to the two sorghum monocrops and the three Brachiaria species. The sorghum and Brachiaria consortium resulted in a reduction in grain yield, but the Brachiaria implantation systems in the row, interrow and spread were the most promising. The sorghum hybrid DKB 551 was the most sensitive to the competition with Brachiaria, although there were no grain yield differences in the intercropping. The Brachiaria intercropped in the interrow and in the row + interrow, mainly with B. ruziziensis, were the most promising for the production of dry mass and total crude protein. The cultivation of Brachiaria intercropped with sorghum provided a greater contribution of dry mass in the off-season, an important fact for the no-tillage system in the agricultural production systems of the Brazilian Cerrado.

ABSTRACT. The productive capacity of soybeans is associated with the adaptation of the culture to the cultivation environment. Factors such as a high number of pods, the weight of a thousand grains, and grain number are essential factors in determining cultivars of high productive potential. The launching of new varieties associated with new technologies makes it necessary to know the performance of these varieties in different growing environments. This study aimed to analyze the agronomic performance of transgenic soybean cultivars under Cerrado conditions. The experimental design used completely randomized blocks; six of the twelve cultivars used RR1 technology and the remaining six used RR2BT. The cultivars were grown in five distinct locations in the southwest region of Goiás. The results demonstrated no increments in the grain yield of the RR1 or RR2BT technologies and the precocity of the cultivars also did not favor an increase in grain yield. The localities of Jataí and Rio Verde did not influence the cultivar cycle.

RESUMO. A adoção da tecnologia Roundup Ready® e o cultivo de segunda safra alteraram os métodos de controle químico e o manejo das plantas daninhas na região sudoeste do Estado de Goiás, Brasil. Tendo em vista estas alterações, este estudo teve o objetivo de realizar um levantamento fitossociológico em áreas de soja resistente ao glyphosate e soja convencional na safra principal e sorgo, milho, milheto ou pousio em sucessão na segunda safra. Foi constituída uma matriz multivariada da composição florística e calculado o valor indicador do número de indivíduos e biomassa seca das espécies. Com base no número de indivíduos as espécies Chamaesyce hirta, Bidens subalternans e Cissampelos ovolifolia foram típicas de áreas de cultivo com soja resistente ao glyphosate, enquanto que Euphorbia heterophyla apresentou valor indicador para áreas de cultivo de soja convencional. Na safrinha, os valores indicadores significativos foram observados para: Crotalaria spectabilis, nas áreas de milho; Cenchrus echinatus no sorgo; e Commelina benghalensis, Sida glaziovii, Ipomoea grandifolia, Sida rhombifolia e Ipomoea cordifolia, nas áreas com milheto. A espécie Conyza bonariensis foi típica do período que antecede a aplicação de herbicidas em pós-emergência na safra. A soja voluntária apresentou-se como típica para o período que antecede a aplicação de herbicidas em pós-emergência na safrinha. Foram registradas plantas daninhas de difícil controle, tolerantes e resistentes às aplicações de herbicidas nas áreas estudadas.

ABSTRACT. Roundup Ready® technology adoption and the cultivation of a second crop have changed chemical control methods and weed management in the southwest region of Goiás State, Brazil. Considering these changes, this study aimed to perform a phytosociological survey in areas with glyphosate resistant soybeans and conventional soybeans as the main harvest and sorghum, maize, millet or fallow in succession as the second harvest. A multivariate matrix of the floristic composition was constructed, and the indicator values of the individual number and dry biomass of species were measured. Based on the number of individuals, the species Chamaesyce hirta, Bidens subalternans, and Cissampelos ovolifolia were typical of areas cultivated with glyphosate-resistant soybean, while Euphorbia heterophyla presented indicator values of areas with conventional soybean cultivation. During the second harvest period, significant indicator values were observed for Crotalaria spectabilis in maize areas, Cenchrus echinatus in sorghum, and Commelina benghalensis, Sida glaziovii, Ipomoea grandifolia, Sida rhombifolia, and Ipomoea cordifolia in areas with millet. The species Conyza bonariensis was typical in the period before the herbicide application at post-emergence in harvest. Volunteer soybean presented as typical for the period before the herbicide application at post-emergence in the second harvest. Weeds that were difficult to control or were tolerant and resistant to the herbicide applications were recorded in the areas studied.

RESUMO Entre as matérias-primas renováveis destinadas à produção de etanol, distinção vem sendo dada ao sorgo sacarino, destacando-se o fato de ser uma cultura totalmente mecanizável. Entretanto, o uso intensivo de máquinas agrícolas provoca degradação estrutural do solo, principalmente quando realizada em condições inadequadas de umidade. Objetivou-se avaliar a qualidade física de um Latossolo Vermelho Distroférrico sob compactação e componentes do rendimento de sorgo sacarino para épocas de semeadura em safrinha no Cerrado brasileiro. O experimento foi instalado no delineamento de blocos ao acaso, em esquema de parcelas subdivididas, com quatro repetições. Nas parcelas, foram avaliados cinco níveis de compactação obtidos pelo tráfego de um trator agrícola nas seguintes intensidades de tráfego: 0 (ausência de compactação adicional), 1, 2, 7 e 15 passadas no mesmo lugar. As subparcelas foram constituídas por três épocas de semeadura do sorgo sacarino na safrinha de 2013 (20/01, 17/02 e 16/03). Foi avaliada a qualidade física do solo, por meio do intervalo hídrico ótimo (IHO), a limitação hídrica, além das variáveis produtivas e tecnológicas da cultura. O monitoramento do conteúdo de água no solo indicou redução da frequência de conteúdos de água no solo dentro dos limites do IHO (Fdentro) com o aumento da intensidade de tráfego agrícola (T0 = T1 = T2>T7>T15), tendo a produtividade associação direta com a disponibilidade hídrica do solo. Por sua vez, a semeadura feita em janeiro apresentou maior qualidade industrial, porém com redução da produtividade de colmos a partir da densidade do solo de 1,26 Mg m-3, com produtividade máxima de 50 Mg ha-1 nessa época de cultivo. O cultivo do sorgo sacarino na safrinha é uma alternativa promissora; no entanto, necessita de cautela quanto ao cultivo em condições de riscos climáticos acentuados por causa da baixa produtividade de colmos.

ABSTRACT Increasing attention has recently been given to sweet sorghum as a renewable raw material for ethanol production, mainly because its cultivation can be fully mechanized. However, the intensive use of agricultural machinery causes soil structural degradation, especially when performed under inadequate conditions of soil moisture. The aims of this study were to evaluate the physical quality of aLatossolo Vermelho Distroférrico (Oxisol) under compaction and its components on sweet sorghum yield forsecond cropsowing in the Brazilian Cerrado (Brazilian tropical savanna). The experiment was conducted in a randomized block design, in a split plot arrangement, with four replications. Five levels of soil compaction were tested from the passing of a tractor at the following traffic intensities: 0 (absence of additional compaction), 1, 2, 7, and 15 passes over the same spot. The subplots consisted of three different sowing times of sweet sorghum during the off-season of 2013 (20/01, 17/02, and 16/03). Soil physical quality was measured through the least limiting water range (LLWR) and soil water limitation; crop yield and technological parameters were also measured. Monitoring of soil water contents indicated a reduction in the frequency of water content in the soil within the limits of the LLWR (Fwithin) as agricultural traffic increased (T0 = T1 = T2>T7>T15), and crop yield is directly associated with soil water content. The crop sown in January had higher industrial quality; however, there was stalk yield reduction when bulk density was greater than 1.26 Mg m-3, with a maximum yield of 50 Mg ha-1 in this sowing time. Cultivation of sweet sorghum as a second crop is a promising alternative, but care should be taken in cultivation under conditions of pronounced climatic risks, due to low stalk yield.

O consórcio tem sido utilizado para produção de grãos e forragem, porém poucos estudos foram realizados com a cultura do sorgo granífero na região Centro-Oeste. Portanto, o objetivo deste trabalho foi o de identificar, na safrinha, o consórcio de sorgo e braquiária, implantadas em duas profundidades de semeadura, que proporcione maiores rendimentos de grãos, massa seca (palhada) e proteína bruta (forragem) com dois cortes nas plantas de braquiária na entressafra. O ensaio foi instalado a campo, em Rio Verde-GO em 05 de março de 2009. Utilizou-se o delineamento experimental de blocos casualizados em esquema fatorial 2x3+1+3, correspondendo a duas profundidades de semeadura da braquiária (2 e 10 cm) e três espécies de braquiária (Brachiaria decumbens (Staf), B. brizantha (Hoschst) cv. Marandu e B. ruziziensis Germain et Evrard) semeadas na entrelinha do sorgo granífero DKB 599, além de quatro tratamentos adicionais sendo um para o monocultivo de sorgo e outros três para cada espécie de braquiária. Os resultados permitiram constatar que o consórcio do sorgo granífero com braquiária na entrelinha apresentou potencial para produção de grãos (exceto da associação com a B. decumbens, semeada a 10 cm de profundidade, e com a B. ruziziensis, semeada a 2 cm), massa seca e proteína bruta, demonstrando a viabilidade para o sistema de cultivo em plantio direto na região Central do Brasil.

The intercropping system has been used to produce grain and forage, but few trials have been conducted with sorghum in the Central-West region of Brazil. Therefore, the objective this study was to identify, in the off-season cultivation, the intercropping of sorghum and brachiaria that provides higher grain, dry matter (straw) and crude protein (forage), yieds with two cuttings in off-season brachiaria . The field trial was installed in RioVerde-GO, March 5, 2009. The experiment was arranged in a randomized complete block design in a factorial scheme 2x3+1+3, corresponding to two sowing depths of brachiaria (2 and 10 cm) and three species (Brachiaria decumbens, Brachiaria brizantha cv.Maranduand and B. ruziziensis) sowed in the interrow of DKB 599 grain sorghum. In addition, four treatments corresponding to one sorghum monoculture and three to each brachiaria species were also installed. The intercrop of sorghum with brachiaria in the interrow had potential to produce grain (except the intercropping with the B.decumbens, sown at the depth of 10 cm, and with the B.ruziziensis, at 2 cm), dry matter and crude protein, showing the viability of the no-tillage cultivation in the Central-West region of Brazil.

O tratamento de sementes com inseticidas é um método eficiente que auxilia o manejo integrado de pragas, porém, há escassez de informações de produtos que apresentem seletividade para a cultura do sorgo. O objetivo deste trabalho foi o de avaliar a influência do tratamento de sementes de sorgo com inseticidas, contendo um ou dois princípios ativos, sem e com o armazenamento por 30 dias, na fase inicial de desenvolvimento das plantas. O experimento foi conduzido na Fesurv-Universidade de Rio Verde, em Rio Verde-GO com dez inseticidas (thiodicarb, fipronil, acephate, thiametoxam, imidacloprid, [imidacloprid+thiodicarb], imidacloprid+thiodicarb, imidacloprid+fipronil, thiametoxam+thiodicarb, thiametoxam+fipronil, acrescido da testemunha sem inseticida) sem e com o armazenamento das sementes por 30 dias. Os resultados obtidos permitiram constatar que o armazenamento por 30 dias das sementes de sorgo tratadas com inseticidas diminui o percentual de germinação. A mistura imidaclopridrid+thiodicarb apresenta maior potencial para uso no tratamento de sementes de sorgo. O inseticida acephate causa fitotoxicidade às plântulas de sorgo ao contrário do fipronil, thiametoxam e a mistura thiametoxam+thiodicarb que não prejudicam o vigor das sementes de sorgo.

Seed treatment with insecticides is an effective tool in integrated pest management, but information on selective products to treat sorghum seeds is limited. The objective of this study was to evaluate the effects of treating sorghum seeds with insecticides containing one or two active ingredients, with and without storage for 30 days, on the early plant development. The experiment was conducted at Fesurv-Universidade de Rio Verde, in Rio Verde-GO, using ten insecticides (thiodicarb, fipronil, acephate, thiamethoxam, imidacloprid, [imidacloprid+thiodicarb], imidacloprid+thiodicarb, imidacloprid+fipronil, thiamethoxam+thiodicarb, thiamethoxam+fipronil, plus a non-insecticide control, with and without 30 day seed storage. The results showed that storage of sorghum seeds treated with insecticides for 30 days reduced the germination percentage. The imidacloprid+thiodicarb mixture has more potential for treating sorghum seeds. The insecticide acephate causes more phytotoxicity to the sorghum seedlings compared to fipronil, thiamethoxam and the thiamethoxam+thiodicarb mixture. The insecticides did not adversely affect sorghum seed vigor.

As produções de feijão-caupi, atualmente, no Brasil, são baixas em função, especialmente, do uso de materiais de baixa capacidade produtiva, associado à utilização de sementes de baixa qualidade. Assim, objetivou-se com este trabalho avaliar as características agronômicas e qualidade fisiológica de sementes de diferentes cultivares de caupi nas condições edafoclimáticas do cerrado goiano. Empregou-se o delineamento de blocos casualizados com quatro repetições. Os tratamentos foram constituídos por oito cultivares de caupi (BRS Guariba, BRS 17 Gurguéia, BRS Rouxinol, BRS Marataoã, Patativa, BRS Tracuateua, BRS Milênio e CE 315), recomendados para as regiões Norte e Nordeste do Brasil. O efeito dos tratamentos foram significativos para todos os caracteres avaliados. As cultivares BRS Guariba, BRS 17 Gurguéia e BRS Marataoã apresentaram menores problemas com oídio. Os genótipos de caupi mais produtivos foram BRS Guariba e BRS Gurguéia, com 2.211 e 2.196 kg ha-1 de grãos, respectivamente. A qualidade fisiológica de sementes de caupi foi influenciada pelas cultivares testadas. As cultivares de tegumento colorido caupi CE 315, BRS Gurguéia, BRS Rouxinol, BRS Marataoã e Patativa produziram sementes de melhor qualidade fisiológica, comparativamente, com as cultivares de tegumento branco BRS Tracuateua, BRS Milênio e BRS Guariba.

The productivities of cowpea are low, depending on the use of low productivity capacity cultivar planted, associated with the use of low-quality seeds. The objective of this work was to evaluate the agronomic characteristics and physiological quality in seed lots of different cultivar of cowpea in the "Cerrado", Goiás State, Brazil. The experimental design was a complete block with four replicates. The treatments were eight cultivar of cowpea (BRS Guariba, BRS 17 Gurguéia, BRS Rouxinol, BRS Marataoã, Patativa, BRS Tracuateua, BRS Milênio e CE 315), recommended for the North and Northeast regions of Brazil. The effects of the treatments were considerable for all the characteristics assessed. The cultivar BRS Guariba, BRS 17 Gurguéia and BRS Marataoã, presented less intense powdery mildew symptoms. The cultivar presenting higher yield were BRS Guariba and BRS Gurguéia, with 2,211 and 2,196 kg ha-1 of grain, respectively. The results showed that physiological seed quality influenced productivity of the cultivar. The cultivar BRS CE 315, BRS Gurguéia, BRS Rouxinol, BRS Marataoã and Patativa, with colored hull, produced seeds of better physiological quality compared, to the cultivar of white hull BRS Tracuateua, BRS Milênio and BRS Guariba.