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It was evaluated the effects of different types of mulching of soil in the cultivation of crisphead lettuce (Lactuca sativa L.), cultivar “Lucy Brown”, in the spring period, on weed control, soil temperature and productivity. The experiment was arranged in a randomized block design with four treatments and five replications in plots of 14.0m2. The following coverages were studied: Pennisetum glaucum L., Avena strigosa, Brachiaria ruziziensis, plus the control treatment (soil without mulching). The use of mulching of soil, P. glaucum and B. ruziziensis, proved to be a beneficial practice, reducing the soil temperature by up to 5ºC. There was a lower incidence of weeds with the use of the P. glaucum and A. strigosa coverages. The use of mulch did not provide a significant gain in productivity, however, there was a gain regarding the quality of the product, since the coverage with P. glaucum provided an increase in the size of the head (fresh mass of the commercial head). Se evaluaron los efectos de diferentes tipos de mantillo de suelo sobre el cultivo de lechuga americana (Lactuca sativa L.), cultivar “Lucy Brown”, sobre el control de malezas, temperatura del suelo y productividad. El diseño experimental utilizado fue de bloques al azar, con cuatro tratamientos y cinco repeticiones en parcelas de 14.0 m2. Se estudiaron las siguientes coberturas: mijo (Pennisetum glaucum L.), avena negra (Avena strigosa), ruziziensis (Brachiaria ruziziensis), más el tratamiento testigo (suelo sin mantillo). El uso de mantillo de tierra, mijo y ruziziensis, resultó ser una práctica ventajosa, reduciendo la temperatura hasta en 5ºC. Hubo una menor incidencia de malezas con el uso de cobertura de mijo y avena. El uso de mantillo no proporcionó una ganancia significativa en la productividad, sin embargo, hubo una ganancia en términos de calidad del producto, ya que la cobertura de mijo proporcionó un aumento en el tamaño de la cabeza (masa fresca de la cabeza comercial). Avaliaram-se os efeitos de diferentes tipos de cobertura morta de solo no cultivo da alface (Lactuca sativa L.) americana, cultivar “Lucy Brown”, sobre o controle de plantas daninhas, a temperatura do solo e a produtividade. O delineamento experimental utilizado foi o de blocos casualizados, com quatro tratamentos e cinco repetições em parcelas de 14,0m2. Estudaram-se as seguintes coberturas: milheto (Pennisetum glaucum L.), aveia preta (Avena strigosa), ruziziensis (Brachiaria ruziziensis), mais o tratamento controle (solo sem cobertura morta). A utilização da cobertura morta de solo, milheto e ruziziensis, mostrou-se como uma prática vantajosa, reduzindo a temperatura em até 5ºC. Houve menor incidência de plantas daninhas com o uso das coberturas milheto e aveia. O uso de cobertura morta não proporcionou um ganho significativo na produtividade, no entanto, houve ganho quanto a qualidade do produto, visto que a cobertura com milheto proporcionou um aumento no tamanho da cabeça (massa fresca da cabeça comercial).

Made available in DSpace on 2020-12-12T02:16:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-09-01 This study aimed to evaluate whether silicon application in the nutrient solution is efficient in relieving stress caused by nutrient deficiency (N, K, Ca, Mg, and S) in the forages BRS Zuri (Panicum maximum) and BRS RB331 Ipyporã (Brachiaria ruziziensis × Brachiaria brizantha). Two experiments were carried out in a greenhouse with both forages, with plants grown in a nutrient solution in pots filled with washed sand. Treatments were arranged in a completely randomized block design, with five replications and consisted of complete solution (control) and individual omission of nitrogen, potassium, calcium, magnesium, and sulfur in the absence (−Si) and presence of silicon (+Si) at a concentration of 2 mmol L−1 applied via nutrient solution as stabilized potassium sodium silicate. The dry mass of the shoot, root, and clump residual material, accumulation and use efficiency of nutrients, and the description of symptoms of nutritional deficiency were evaluated. Silicon addition in the nutrient solution favored shoot dry matter production and root dry matter production of both forages, in treatments with K, Ca, and Mg omission; the same effect was not observed for N and S. We conclude that the application of silicon attenuates the effects of potassium, calcium, and magnesium deficiency in forages BRS Zuri and BRS RB331 Ipyporã, as it increases the accumulated shoot dry mass, due to the greater efficiency in the use of these nutrients. The beneficial effect of silicon was not important in forage plants with nitrogen and sulfur deficiency. Department of Soils and Fertilizers School of Agricultural and Veterinarian Sciences São Paulo State University “Júlio de Mesquita Filho”(UNESP), Jaboticabal Department of Agronomy Mato Grosso State University (UNEMAT), Alta Floresta Department of Soils and Fertilizers School of Agricultural and Veterinarian Sciences São Paulo State University “Júlio de Mesquita Filho”(UNESP), Jaboticabal

This experiment was aimed to investigate the production characteristics and nutritive quality of Ruzi grass by varying levels of organic and inorganic fertilizer viz. cow dung (CD) and urea fertilizer (UF), respectively. The treatments were arranged into a factorial design and grouped according to a completely randomized design with three replications. Three doses of CD (0; 5; and 10 t/ha) were applied at sowing and four UF doses were applied as top dressing (0, 25, 50 and 100 kg/ha). The application of CD and UF have a positive effect on the length of leaves (p=0.00 and p=0.02) but their interactions are not significantly different (p=0.12). The effect of CD, UF and their interaction significantly increased the number of leaves (p=0.00), the number of tillers (p=0.00) and dry matter yield (p=0.00). There were no significant effect of CD and interaction on the leaf/stem ratio (p=0.17 and p=0.23, respectively) but UF slightly increased the ratio (p=0.00), CP% (p£0.00), NDF% (p£0.00) and ADF% (p£0.00). The best combination of fertilizer could be noted at 50 kg/ha UF and 10 t/ha CD to obtain better results. It might recommend that better fertilizer management can improve productivity as well as the nutritional quality of Ruzi grass.

Some species of the genus Brachiaria are cultivated worldwide in tropical and subtropical climate regions as the main feed for ruminants. Several studies report photosensitization by Brachiaria decumbens, Brachiaria brizantha, and Brachiaria humidicola, but the poisoning by Brachiaria ruziziensis have been reported only twice. Cutaneous and hepatic lesions may be caused by the steroidal saponins present in the leaves or by the mycotoxin sporidesmin produced by the saprophyte fungus Pithomyces chartarum. The present report describes the clinical and pathological changes observed in an outbreak of hepatogenic photosensitization in sheep kept in B. ruziziensis pastures. In addition, the present study will provide a better understanding of the etiology of this photosensitization through the evaluation of the saponin protodioscin and the spore count of P. chartarum. Santa Ines and Lacaune mixed-breed sheep showed signs of photosensitization after feeding B. ruziziensis. Clinical signs included jaundice, apathy, dehydration, and photosensitization characterized by facial edema and cutaneous scars, especially in the ears. Pathological examination of the liver revealed diffuse infiltrates of foamy cells, rare multinucleated cells, and mild enlargement of hepatocytes (megalocytosis). The skin showed acute epidermal and dermal necrosis with occlusive thrombi. B. ruziziensis showed low levels of protodioscin (0.020 ± 0.024% in mature leaves and 0.065 ± 0.084% in sprouts) but high P. chartarum spore counts (mean of 479,844 ± 443,951 spores/g plant). Thus, sheep grazing B. ruziziensis pastures must be closely monitored because of the risk of photosensitization.

In the current agriculture one of the main limiting factors in soybean yield is the occurrence of dry seasons during the crop cycle. The use of cover crops associated with a no-tillage practice, has been widely used for the improvement of soils and especially in areas of sandy soils, to reduce the effects caused by the low availability of water. Concerning the hypothesis that only the vegetation cover is not enough to solve the effects of water deficit, the objective was to evaluate the combined effect of different irrigation management in a no-tillage system on cultural remains of Brachiaria in different soybean cultivars. The field research was carried out under a center pivot at the Chapadao Foundation, in an area on Braquiaria vegetable residues, where five irrigation depths were implemented and six soybean cultivars in a randomized block design. The following quantitative variables were evaluated: plant height (AP), height of insertion of the first pod (AIV), number of plants (NP), number of pods per plant (NVP), number of grains per pod (NGV), number of grains per plant (NGP), one hundred grain mass (MCG), canopy temperature (DOSSEL) and productivity (PROD), irrigation has an effect mainly on the mass variable of one hundred grains (MCG), obtaining a linear growth in the values at as there is an increase in water availability in the soil. En el escenario agrícola actual, uno de los principales factores limitantes en la productividad de la soja es la aparición de cultivos de verano durante el ciclo del cultivo. El uso de cubiertas vegetales, asociado con la práctica de la siembra directa, se ha utilizado ampliamente para mejorar los suelos y, especialmente en áreas con textura arenosa, para reducir los efectos causados por la baja disponibilidad de agua. Bajo la hipótesis de que solo la cubierta vegetal no es suficiente para remediar los efectos del déficit hídrico, el objetivo fue evaluar el efecto combinado de la gestión de riego diferente en el sistema de labranza cero en restos culturales de brachiaria, en diferentes cultivares de soja. La investigación de campo se realizó bajo un eje central, en la Fundación Chapadão, en un área sobre restos de plantas de brachiaria, donde se implementaron cinco hojas de riego suplementarias y seis cultivares de soja. El diseño utilizado fueron los bloques aleatorizados en un esquema de tira. Se evaluaron las siguientes variables cuantitativas: altura de la planta (AP), altura de inserción de la primera vaina (AIV), número de plantas (NP), número de vainas por planta (NVP), número de granos por vaina (NGV), número de granos por planta (NGP), masa de cien granos (MCG), temperatura del dosel (DOSSEL) y productividad (PROD), el riego tiene un efecto principalmente en la masa variable de cien granos (MCG), obteniendo un crecimiento lineal en los valores a ya que hay un aumento en la disponibilidad de agua en el suelo. No cenário da agricultura atual, um dos principais fatores limitantes na produtividade de soja, é a ocorrência de verânicos durante o ciclo da cultura. O uso de coberturas vegetais, associado a prática do plantio direto, vem sendo amplamente utilizado, para a melhoria dos solos e, principalmente em áreas de textura arenosa, reduzir os efeitos ocasionados pela baixa disponibilidade de água. Sob a hipótese de que apenas a cobertura vegetal não é suficiente para sanar os efeitos de défice hídrico, objetivou-se avaliar o efeito combinado de diferentes manejos de irrigação em sistema de plantio direto sobre restos culturais de braquiária, em diferentes cultivares de soja. O experimento foi conduzido sob pivô central, na Fundação Chapadão, em área sobre restos vegetais de braquiária, onde foram implementadas cinco lâminas de irrigação suplementar e seis cultNo cenário da agricultura atual, um dos principais fatores limitantes na produtividade de soja, é a ocorrência de verânicos durante o ciclo da cultura. O uso de coberturas vegetais, associado a prática do plantio direto, vem sendo amplamente utilizado, para a melhoria dos solos e, principalmente em áreas de textura arenosa, reduzir os efeitos ocasionados pela baixa disponibilidade de água. Sob a hipótese de que apenas a cobertura vegetal não é suficiente para sanar os efeitos de défice hídrico, objetivou-se avaliar o efeito combinado de diferentes manejos de irrigação em sistema de plantio direto sobre restos culturais de braquiária, em diferentes cultivares de soja. O experimento foi conduzido sob pivô central, na Fundação Chapadão, em área sobre restos vegetais de braquiária, onde foram implementadas cinco lâminas de irrigação suplementar e seis cultivares de soja. O delineamento utilizado foi o de blocos casualizados em esquema de faixas. Foram avaliadas as seguintes variáveis resposta: altura de plantas (AP), altura de inserção da primeira vagem (AIV), número de plantas (NP), número de vagens por planta (NVP), número de grãos por vagem (NGV), número de grãos por planta (NGP), massa de cem grãos (MCG), temperatura do dossel (DOSSEL) e produtividade (PROD), a irrigação apresenta efeito principalmente na variável massa de cem grãos (MCG), obtendo um crescimento linear nos valores à medida em que há o aumento da disponibilidade hídrica no solo.ivares de soja. O delineamento utilizado foi o de blocos casualizados em esquema de faixas. Foram avaliadas as seguintes variáveis resposta: altura de plantas (AP), altura de inserção da primeira vagem (AIV), número de plantas (NP), número de vagens por planta (NVP), número de grãos por vagem (NGV), número de grãos por planta (NGP), massa de cem grãos (MCG), temperatura do dossel (DOSSEL) e produtividade (PROD), a irrigação apresenta efeito principalmente na variável massa de cem grãos (MCG), obtendo um crescimento linear nos valores à medida em que há o aumento da disponibilidade hídrica no solo.

A antecipação da aplicação de nitrogênio em sistemas de cultivo, utilizando plantas de cobertura, para evitar as perdas do nutriente no perfil do solo, bem como aumentar a matéria seca produzida pela planta de cobertura, apresenta-se como uma alternativa para melhorar a eficiência de uso desse nutriente. O manejo do nitrogênio é de grande importância para o sistema braquiária-milho, onde tradicionalmente, aplica-se o N no plantio e em cobertura na cultura principal (milho). Objetivouse com este trabalho, avaliar a eficiência da antecipação da adubação nitrogenada para a cultura do milho, utilizando a braquiária como cultura antecessora. O experimento foi conduzido na área experimental da Universidade Federal de Goiás, em Jataí – GO, com histórico de plantio em sucessão soja-milho/sorgo nos últimos 20 anos, e destaque para o teor de Matéria Orgânica do solo que é de 39,5 g kg-1. O delineamento utilizado foi de blocos ao acaso, em esquema fatorial 5x2+1, com 4 repetições. O primeiro fator correspondeu a cinco doses de nitrogênio: 0; 50; 100; 150 e 200 kg ha-1, utilizando como fonte de N a ureia convencional. O segundo fator foi representado pelas épocas de aplicação dessas doses de nitrogênio na cultura da braquiária cultivada como planta de cobertura, sendo a época 1: aplicação do nitrogênio 90 dias pré semeadura do milho e época 2: aplicação do nitrogênio 60 pré-semeadura do milho e um tratamento adicional com adubação nitrogenada convencional, representada por 150 kg ha-1 de nitrogênio, de forma não antecipada, aplicada na cultura do milho, dividida em adubação de plantio e cobertura. Foram avaliadas na braquiária, 5 dias antes da dessecação, as seguintes variáveis: matéria seca, nitrogênio nas folhas e índice de vegetação normalizada. No milho, foram avaliados: índice de vegetação normalizada, diâmetro de colmo, atividade da enzima nitrato redutase, clorofila e nitrogênio nas folhas, altura de plantas e da inserção da espiga, componentes da produção e produtividade de grãos. Com exceção a dose de 200 kg ha1 de N aplicada 90 dias antes da semeadura do milho, a antecipação da adubação nitrogenada para esta cultura, utilizando a braquiária como planta de cobertura, se mostrou tão eficiente quando a adubação convencional. The anticipation of nitrogen application in cultivation systems using cover crops to avoid nutrient losses in the soil profile, as well as increase the dry matter produced by cover crops, is an alternative to improve soil efficiency use of this nutrient. Nitrogen management is of great importance for the brachiaria-maize system, where N is traditionally applied at planting and covering in the main crop (maize). The aim of this work was to evaluate the efficiency of the anticipation of nitrogen fertilization for corn crop, using brachiaria as a predecessor crop. The experiment was conducted at the experimental field of the Federal University of Goiás / Jataí Regional, with a history of planting in succession soybean-corn/sorghum in the last 20 years, and emphasis on the content of Organic Matter of Soil that reaches 39.5 g kg-1. A randomized complete block design was used in a 5x2 + 1 factorial scheme with 4 replications. The first factor corresponded to five nitrogen rates: 0; 50; 100; 150 and 200 kg ha-1, using conventional urea as N source. The second factor was represented by the times of application of these nitrogen rates in the brachiaria cultivated as cover crops, being season 1: application of nitrogen 90 days before planting of corn and season 2: application of nitrogen 60 days before planting and an additional treatment with conventional nitrogen fertilization, represented by 150 kg ha-1 of nitrogen, unanticipated, applied to the corn crop, divided into planting and mulching fertilization. The following variables were evaluated in the brachiaria, 5 days before desiccation: dry matter, leaf nitrogen, normalized vegetation index and nitrogen release in the brachiaria straw. In maize were evaluated: normalized vegetation index, stalk diameter, activity of nitrate reductase enzyme, chlorophyll and nitrogen in leaves, plant height and cob insertion, components of grain yield and yield. With the exception of the 200 kg ha-1 rate of N applied 90 days before corn sowing, the antecipation of nitrogen fertilization for this crop, using braquiária as a cover plant, proved to be as efficient as conventional fertilization.

A low number of Brachiaria ruziziensis (Syn. Urochloa) cultivars available on the market and a lack of information about its forage potential have made it difficult to expand its cultivated area, and have therefore made it necessary to implement a breeding program for this species. Thus, the objective of this work was to evaluate the nutritional value of ten improved populations of Brachiaria ruziziensis (Syn. Urochloa) and two controls (B. ruziziensis cv. Kennedy and B. brizantha cv. Marandu). The experimental design was a randomized block design with three replications in five sections. The data were submitted to analysis of variance in the subdivided plot in which the primary factors were the populations and the secondary cuts. The Tukey test was used at 5% of significance for the comparison of means. The genotypes used came from the third recurrent selection cycle of Embrapa dairy cattle, originating from the interbreeding of clones which had been identified as superior. The height of the cuts was 10 cm in relation to the ground. The material was cut and weighed in the field to obtain the sample weights to determine the nutritional forage value. After drying, the samples were ground in 1 mm sieves for chemical analyzes and in vitro digestibility. The best CP, ADF and NDF levels observed in IV populations (lower levels of ADF and NDF at 93 days of cut interval and lower NDF contents at 35 and 41 days of cut interval), population VI (higher CP content in the interval of 93 days, lower DM content at 64 and 93 days of cut interval, and lower NDF content at 35 and 64 days of cut interval) showed that these populations can be evaluated under grazing even at an advanced maturation stage. The objective of these selections was to evaluate the nutritional value of improved populations of Brachiaria ruziziensis (Syn. Urochloa) in order to obtain more homogeneous populations for implantation of grazing experiments. O reduzido número de cultivares de Brachiaria ruziziensis (Syn. Urochloa) disponíveis no mercado, a ausência de informações sobre seu potencial forrageiro que vem dificultando a expansão de sua área cultivada tornaram necessário a implantação de um programa de melhoramento genético desta espécie. O objetivo do trabalho foi avaliar o valor nutricional de dez populações melhoradas e duas testemunhas (B. ruziziensis cv. Kennedy e B. brizantha cv. Marandu). O delineamento experimental utilizado foi o de blocos ao acaso com três repetições, em cinco cortes. Os dados foram submetidos à análise de variância conjunta no esquema de parcela subdividida no qual o fator primário foram as populações e o secundário os cortes. Para a comparação das médias utilizou-se o teste de Tukey a 5% de significância. Os genótipos utilizados foram provenientes do terceiro ciclo de seleção recorrente na Embrapa Gado de Leite, originadas do intercruzamento de clones identificados como superiores. A altura dos cortes foi de 10 cm em relação ao solo. O material foi cortado e pesado em campo para obtenção dos pesos das amostras para realização das avaliações do valor nutritivo da forragem. Após a secagem, procedeu-se a moagem das amostras em peneira de 1 mm para realização das análises químicas e digestibilidade in vitro. Os melhores teores de PB, FDA e FDN observados nas populações IV (menores teores de FDA e FDN aos 93 dias de intervalo de corte e menores teores de FDN aos 35 e 41 dias de intervalo), população VI (maior teor de PB no intervalo de corte de 93 dias, menor teor de FDA aos 64 e 93 dias de intervalo de corte e menor teor de FDN aos 35 e 64 dias de intervalo de corte) demonstram que mesmo em avançado estágio de maturação essas populações podem ser avaliadas sob pastejo. O objetivo dessas seleções foi avaliar o valor nutricional de populações melhoradas de Brachiaria ruziziensis (Syn. Urochloa) visando obter populações mais homogêneas para implantação de experimentos de avaliações sob pastejo.

O sistema de plantio direto sobre a palha é uma tecnologia consolidada e considerada a segunda revolução verde (Pereira, 1997). Atualmente, as pesquisas e validações de campo vem buscando seu aprimoramento em função das condições ambientais e dos fatores de crescimento nas diversas regiões. Neste sentido, o sucesso deste sistema deve-se a palha deixada por culturas de cobertura sobre a superfície do solo, criando um ambiente favorável ao crescimento e desenvolvimento da cultura principal subsequente (Alvarenga et al., 2001). A modernização dos sistemas de produção tem levado a busca por culturas de cobertura que não se restrinja apenas à proteção do solo, mas que apresente outras funcionalidades (Jian et al., 2020). Assim, embora a escolha da planta de cobertura seja um processo de certa forma complexo devido à pouca disponibilidade de famílias/espécies de plantas, este processo é primordial para garantir a evolução e os aumentos em produtividade do sistema. Na escolha desta planta devem ser considerados os objetivos para a lavoura, por exemplo, proteção e reestruturação física, química e biológica do solo, controle de nematoides e/ou interrupção de ciclos de pragas e doenças, aumento da biodiversidade, entre outros. O aumento da biodiversidade de plantas em cobertura, como ocorrem em sistemas consorciados, promove o aumento das características benéficas sobre o solo e, consequentemente, na cultura principal pela ação aditiva e conjugada das espécies (Silveira et al., 2020). Para exemplificar, o consórcio entre uma gramínea e uma leguminosa aumenta a proteção e estruturação do solo, e a ciclagem de nutrientes pela maior ação exploratória das raízes em profundidade (leguminosas) e subsuperfície (gramínea), além do aumento da biomassa, a qual resultará em maior quantidade e melhor qualidade da palhada em função da diferente relação carbono/nitrogênio (C/N) nas gramíneas e leguminosas (Calvo et al., 2010). Made available in DSpace on 2022-08-24T20:19:37Z (GMT). No. of bitstreams: 1 2020-cpamt-fjw-integracao-lavoura-pecuaria-consorcio-forrageiro-entressafra.pdf: 1078411 bytes, checksum: 6f4cac8927d15246669b042c220a2aae (MD5) Previous issue date: 2020 Editores Técnicos: Antônio Eduardo Furtini Neto; Diego Tolentino de Lima; Dieimisson Paulo Almeida; Hemython Luis Bandeira do Nascimento; Rafael Henrique Fernandes; Ubirajara Oliveira Bilego.

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. 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.

Ipyporã grass, a Brachiaria interspecific hybrid was developed by crossing a genotype of Brachiaria ruziziensis (syn. Urochloa ruziziensis) and an access of Brachiaria brizantha (syn. Urochloa brizantha), which have different nitrogen requirements. Therefore, the objective with work was to verify the nitrogen requirement of the interspecific hybrid of Brachiaria hybrid cv. Ipyporã. Experiment was carried out in a greenhouse in a randomized block design, with twelve treatments and four replications. Treatments consisted of a 4 x 3 factorial arrangement, with four nitrogen doses (0; 100; 200 and 300 mg dm3) and three forages (Brachiaria hybrid cv. BRS Ipyporã, Brachiaria humidicola cv. Llanero and Panicum maximum cv. Zuri). Each experimental plot consisted of a 3 dm³ pot with three plants. Three evaluation harvest were done . B. hybrid had greater response to nitrogen fertilization for number of tillers and leaves than the other forages. However, for the total dry mass, B. hybrid was less responsive to nitrogen than P. maximum grass (high demand) and more responsive than B. humidicola (low demand), which shows that this hybrid has medium nitrogen requirement.

A Região Centro-Oeste possui uma área de 160 milhões de hectares, correspondendo a 18,9% do território brasileiro (IBGE, 2010). No entanto, 119 milhões são estabelecimentos agropecuários em que ~43% são área destinada à preservação da vegetação nativa, segundo a estimativa apresentada pela (Embrapa, 2017) com base nos dados do Cadastro Ambiental Rural. É notório o grande potencial de produção agrícola da região Centro-Oeste, tornando-se o principal polo agropecuário do país. Isto ocorre em função da grande proporção da área encontrada no Bioma Cerrado, caracterizado por relevo suavemente ondulados, solos profundos e bem drenados, favorecendo a agricultura mecanizada (Pedreira et al., 2017). No entanto, estes solos apresentam baixa fertilidade natural e acidez acentuada, que são potencialmente corrigidos. Em termos de produção, a região Centro- Oeste foi responsável por aproximadamente 120 milhões de toneladas (47% da produção nacional de grãos), ranking liderado pelo Mato Grosso com 73,4 milhões de toneladas segundo a Companhia Nacional de Abastecimento (CONAB, 2020). A região também é polo nacional na produção de bovinos de corte, contemplando um rebanho de 73,2 milhões de cabeças, segundo o relatório da Associação Brasileira de Indústrias Exportadoras de Carne (ABIEC, 2019). O posicionamento estratégico, alta tecnologia de produção, relevo e clima também são propícios para o desenvolvimento de sistemas de produção sustentáveis. Assim como ocorre no Brasil como um todo, a configuração de sistemas de produção de alta tecnologia, como a que integra a lavoura com a pecuária, torna a exploração da terra mais eficiente, pois o solo estará coberto por culturas em mais de 80% do tempo (Pedreira et al., 2018). Made available in DSpace on 2022-08-24T20:19:23Z (GMT). No. of bitstreams: 1 2020-cpamt-bcp-culturas-cobertura-entressafra-importancia-recomendacao.pdf: 816068 bytes, checksum: ad5593ea56b7689684fb691f6149640f (MD5) Previous issue date: 2020 Editores Técnicos: Antônio Eduardo Furtini Neto; Diego Tolentino de Lima; Dieimisson Paulo Almeida; Hemython Luis Bandeira do Nascimento; Rafael Henrique Fernandes; Ubirajara Oliveira Bilego.

In intercropping systems, a high plant density can delay the biomass accumulation and affect the water availability to plants. This study aimed to evaluate the soil water dynamics and the crop yield performance in maize and Brachiaria ruziziensis intercropping under different sowing densities of the forage grass. The experiment was conducted in a randomized block design, with treatments associated to the sowing densities (2 kg ha-1, 4 kg ha-1, 6 kg ha-1 and 8 kg ha-1) and the single cropping for both species as controls. The maize plants were evaluated for grain yield and B. ruziziensis for number of plants per hectare and shoot fresh and dry matter. The intercropping performance was evaluated using the land-use efficiency index. The soil water dynamics was monitored in two soil depths (0-0.3 m and 0.3-0.6 m) by using the time domain reflectometry method. The evaluation of soil water storage was carried out from plots with four of the crop systems (single maize or B. ruziziensis, and intercropping with the extreme sowing densities), at four different times. The increase in the sowing density of B. ruziziensis decreased the grain yield of the intercropped maize by 30.8 %. The intercropping system using 2 kg ha-1 of the grass seeds resulted in the best land-use efficiency (23 %). In addition, the intercropping treatments promoted a higher extraction of water from the soil, mainly at the maize growth stages with higher hydric demand (e.g., flowering and grain filling). These systems stimulate the extraction of water from deeper soil layers, when compared to maize in single cropping. RESUMO Em cultivos consorciados, uma alta densidade de plantas pode retardar o acúmulo de biomassa e afetar a disponibilidade hídrica às plantas. Objetivou-se avaliar a dinâmica da água no solo e o desempenho produtivo no consórcio de milho e Brachiaria ruziziensis sob diferentes densidades de semeadura desta forrageira. O experimento foi conduzido em blocos casualizados, com tratamentos associados às densidades de semeadura (2 kg ha-1, 4 kg ha-1, 6 kg ha-1 e 8 kg ha-1) e ambas as espécies em monocultivo como testemunhas. No milho, avaliou-se a produtividade de grãos e, na braquiária, o número de plantas por hectare e as massas verde e seca da parte aérea. O desempenho do consórcio foi avaliado pelo índice de uso eficiente da terra. A dinâmica da água no solo foi monitorada em duas profundidades (0-0,3 m e 0,3-0,6 m), pela técnica de reflectometria no domínio do tempo. A avaliação do armazenamento de água no solo foi realizada a partir de parcelas com quatro dos sistemas de cultivo (milho ou braquiária em monocultivo, e consórcios com as densidades de semeadura extremas), em quatro períodos. O aumento na densidade de semeadura de B. ruziziensis diminuiu a produtividade dos grãos do milho consorciado em 30,8 %. O consórcio usando 2 kg ha-1 de sementes da forrageira proporcionou melhor eficiência no uso da terra (23 %). Ademais, os tratamentos com consórcio promoveram maior extração de água do solo, especialmente nas fases de maior exigência hídrica do milho (e.g., florescimento e enchimento de grãos). Estes sistemas simulam a extração de água em maiores profundidades, quando comparados ao milho em cultivo solteiro.

Forage plant breeders often use visual scores to assess agronomic traits because of the costs associated with in-depth phenotyping in the initial stages of breeding cycles. The aim of this study was to investigate the impact of the number of graders on the effectiveness of indirect selection of high-yielding genotypes and determine an optimal number of graders in the early-stage trials of Urochloa ruziziensis. For that purpose, five graders assessed 2.219 U. ruziziensis genotypes in an augmented block design. Biomass production and vigor scores were evaluated in two cuts and were analyzed using a linear mixed model approach. Vigor scores were analyzed considering each grader's score and the combinations of two, three, four, and five graders. Genetic variance was significant for both traits. Visual evaluation was effective in identifying productive genotypes based on the statistical criteria. The optimal number of graders for indirect selection of high-yielding U. ruziziensis genotypes is three.

Microsporogenesis studies in Brachiaria have been concentrated in the species B. ruziziensis, B. decumbens and B.brizantha and hybrids because they have great importance as forage. Besides the sexual behavior, B. ruziziensis is among a minority of Brachiaria diploid species (2n = 2 × = 18), while most are tetraploid (2n= 4 × = 36) and apomictic. Brachiaria ruziziensis is used in intra and interspecific crossbreedings. For the success of interspecific hybridization, artificial tetraploidization of B. ruziziensis is necessary. The aim of this study was to compare the microsporogenesis in diploid and synthetic tetraploid B. ruziziensis plants and their respective progenies. The slides were prepared by squash technique and stained with 1% propionic carmine for meiocyte analysis and Alexander's stain for pollen viability. Abnormalities were found in all phases of meiosis in the families of the diploid and tetraploid plants and, in general, the rate was considered low, with the percentage varying according to the genotypes. The diploid family was considered more stable. For both families, there is a tendency to reduce the total frequency of abnormalities in the progenies compared to the mother plants. This response indicates that combinations of random crosses or self-fertilization among plants with the same ploidy level were favorable. For the diploid accessions, the pollen viability index was high, reaching up to 88.3%, whereas the tetraploidized plants presented lower values, reaching a maximum of 61.1%. The results will be of interest to researchers involved in tropical forage breeding or conducting intraspecific crosses, since the occurrence of regular meiosis in progenies ensures the formation of viable pollen grains.

Maize and soybean are the main crops used for crop yield on Brazilian Cerrado biome. The off-season maize intercropped with ruzigrass [Urochloa ruziziensis (R. Germ. & C.M. Evrard) Crins (Syn. Brachiaria ruziziensis Germ. & Evrard)] increases soil cover and yield for crops in succession. However, the benefits on maize yield depend on the distribution and radiation-use efficiency (RUE) and its conversion to biomass. This study aimed to evaluate maize and ruzigrass yield in different cultivation systems. The experiment was carried out at Embrapa Agropecuária Oeste, in Dourados, MS, Brazil. The experiment design was randomized blocks, with seven treatments constituted by the combination of spacing between maize rows, single and intercropped, with ruzigrass in distribution methods. Photosynthetically active radiation, chlorophyll, leaf temperature, morphological characteristics and maize mass yield were evaluated in maize at the flowering stage (R1). Maize and ruzigrass yield were evaluated during maize maturation. The reduced spacing in single maize has a higher yield and lower radiation incidence in the ear. Maize intercropped with ruzigrass sown by broadcasting showed higher leaf temperature, lower plant height and lower maize leaf area. Morphological and physiological characteristics and maize grain yield were more influenced by planting methods than the presence of ruzigrass. The highest yield of dry matter and maize grain occurred in reduced spacing in maize, either alone or intercropped with ruzigrass.

Repetitive DNA sequences have been widely used in cytogenetic analyses. The use of gene sequences with a low-copy-number, however, is little explored especially in plants. To date, the karyotype details in Brachiaria spp. are limited to the location of rDNA sites. The challenge lies in developing new probes based on incomplete sequencing data for the genus or complete sequencing of related species, since there are no model species with a sequenced genome in Brachiaria spp. The present study aimed at the physical location of conserved genes in chromosomes of Brachiaria ruziziensis, Brachiaria brizantha, and Brachiaria decumbens using RNAseq data, as well as sequences of Setaria italica and Sorghum bicolor through the fluorescent in situ hybridization technique. Five out of approximately 90 selected sequences generated clusters in the chromosomes of the species of Brachiaria studied. We identified genes in synteny with 5S and 45S rDNA sites, which contributed to the identification of chromosome pairs carrying these genes. In some cases, the species of Brachiaria evaluated had syntenic segments conserved across the chromosomes. The use of genomic sequencing data is essential for the enhancement of cytogenetic analyses.

Endophytic Paraconiothyrium strains associated with Brachiaria spp. and Panicum maximum were screened in vitro and in vivo for antagonism against Sclerotinia sclerotiorum and grass growth promotion. Based on multilocus phylogenetic analyses, three Paraconiothyrium estuarinum strains and two Paraconiothyrium cyclothyrioides strains were identified. In vitro, P. estuarinum strain CML 3699 was the most efficient in S. sclerotiorum mycelial growth inhibition. Volatile organic compounds (VOCs) produced by Paraconiothyrium strains reduced the sclerotia number, sclerotia weight and apothecia number in comparison to the control. The VOCs of P. cyclothyrioides strain CML 3698 promoted higher inhibitory effects on apothecium production. Paraconiothyrium estuarinum CML 3695, when inoculated into Brachiaria ruziziensis seeds, promoted increased biomass in comparison to those in non-inoculated seeds. All strains were sensitive to higher glyphosate doses, which reduced their mycelial development. However, when the mycelia of the endophytic fungi were removed and transferred to new PDA medium, the fungi recovered growth. After desiccation of Paraconiothyrium-inoculated B. ruziziensis with glyphosate, Paraconiothyrium strains recovered the ability to colonize the sclerotia of S. sclerotiorum and reduced carpogenic germination via a Trojan-horse-like mode of action. Considering that grass can be deployed by farmers as a physical barrier to S. sclerotiorum ascospore release, the growth promotion and parasitism of sclerotia exerted by Paraconiothyrium strains towards B. ruziziensis reinforce this disease control strategy.

Para melhor controle e eficiência dos cultivos agrícolas nas regiões semiáridas brasileiras, o uso de avaliações com dados provenientes de sensoriamento remoto em conjunto com sistemas de informações geográficas (SIG) estão sendo amplamente utilizados. Neste trabalho objetivou-se comparar os índices vegetativos em sistema de cultivo de milho e plantas de cobertura do solo nas condições semiáridas do Brejo da Paraíba. A pesquisa foi realizada em Areia, Paraíba, Brasil, nos anos agrícolas de 2018/2019 e 2019/2020. O delineamento foi em blocos casualizados, com quatro repetições, no esquema fatorial 3 × 6, correspondente a três genótipos de milho (cultivar Robusto, milho crioulo Pontinha e híbrido AG1051) e seis sistemas de cultivo de plantas de cobertura [(Brachiaria ruziziensis, milheto (Pennisetum glaucum), feijão guandu (Cajanus cajan), Crotalária espectabilis, Crotalária juncea e como testemunha apenas o solo descoberto)], totalizando 18 tratamentos. Foram avaliados os índices vegetais de Visible Atmospherically Resistant Index, Redness Index, Normalized green-Red Difference Index, Ground Level Image Analysis, Excess Red-Green, Excess Red Vegetative Index, Excess Green Index e o Color Index of Vegetation Extraction. De maneira geral, os resultados demonstraram que para observar diferenças entre os genótipos de milho é indicado o uso do índice Excess Red Vegetative Index. Para observar diferenças do efeito das plantas de cobertura no milho, indica-se o Normalized green-Red Difference.

Made available in DSpace on 2021-06-25T10:54:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Plant-associated microbiomes have been a target of interest for the prospection of microorganisms, which may be acting as effectors to increase agricultural productivity. For years, the search for beneficial microorganisms has been carried out from the characterization of functional traits of growth-promotion using tests with a few isolates. However, eventually, the expectations with positive results may not be realized when the evaluation is performed in association with plants. In our study, we accessed the cultivable sugarcane microbiome under two conditions of agronomic management: organic and conventional. From the use of a new customized culture medium, we recovered 944 endophytic and epiphytic bacterial communities derived from plant roots, stalks, leaves, and rhizospheric soil. This could be accomplished by using a large-scale approach, initially performing an in planta (Cynodon dactylon) screening process of inoculation to avoid early incompatibility. The inoculation was performed using the bacterial communities, considering that in this way, they could act synergistically. This process resulted in 38 candidate communities, 17 of which had higher Indole-3-acetic acid (IAA) production and phosphate solubilization activity and, were submitted to a new in planta test using Brachiaria ruziziensis and quantification of functional traits for growth-promotion and physiological tests. Enrichment analysis of selected communities has shown that they derived mainly from epiphytic populations of sugarcane stalks under conventional management. The sequencing of the V3-V4 region of the 16S rRNA gene revealed 34 genera and 24 species distributed among the phylum Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. We also observed a network of genera in these communities where the genus Chryseobacterium stands out with a greater degree of interaction, indicating a possible direct or indirect role as a keystone taxon in communities with plant-growth promotion capacities. From the results achieved, we can conclude that the approach is useful in the recovery of a set of sugarcane bacterial communities and that there is, evidence of synergistic action providing benefits to plants, and that they are compatible with plants of the same family (Poaceae). Thus, we are reporting the beneficial bacterial communities identified as suitable candidates with rated potential to be exploited as bioinoculants for crops. Universidade Estadual Paulista (Unesp) Faculdade de Ciências Agrárias e Veterinárias Câmpus Jaboticabal, Via de Acesso Prof. Paulo Donato Castellane s/n Programa de Pós-Graduação em Microbiologia Agropecuária Universidade Estadual Paulista (Unesp) Faculdade de Ciências Agrárias e Veterinárias Câmpus Jaboticabal Via de Acesso Prof. Paulo Donato Castellane s/n Universidade Federal de Mato Grosso Instituto de Biociências, Av. Fernando Corrêa Universidade Estadual Paulista (Unesp) Faculdade de Ciências Agrárias e Veterinárias Câmpus Jaboticabal, Via de Acesso Prof. Paulo Donato Castellane s/n Programa de Pós-Graduação em Microbiologia Agropecuária Universidade Estadual Paulista (Unesp) Faculdade de Ciências Agrárias e Veterinárias Câmpus Jaboticabal Via de Acesso Prof. Paulo Donato Castellane s/n FAPESP: 2017/09008-5

Made available in DSpace on 2018-11-26T15:47:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-02-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Nitrate leaching is a primary pathway of nitrogen loss from agricultural systems, and is affected by both tillage and cropped species. However, there is little information on conservation systems without nitrogen fertilization. Nitrate leaching was assessed in soybean (Glycine max) cropped in rotation with the following cover crops under no-till and chiseling: ruzigrass (Brachiaria ruziziensis), grain sorghum (Sorghum bicolor), pearl millet (Pennisetum glaucum), forage sorghum (Sorghum bicolor), Sunn hemp (Crotalaria juncea), triticale (X Triticosecale) and sunflower (Helianthus annuus). Ruzigrass and grain sorghum cropped in the fall/winter resulted in similar NO3 (-) leaching, which was greater under sunflower than under triticale, likely due to high N uptake and immobilization in plant residues. Sunn hemp as a spring crop resulted in higher NO3 (-) leaching than pearl millet at two locations and forage sorghum at one location likely due to a higher N input by biological fixation. Millet resulted in the lowest N leaching by depleting the soil solution. Chiseling/fallow resulted in higher nitrogen leaching as compared with non-fixing N cover crops. Even when N is not applied, it is important to intensify cropping systems in tropical environments using cover crops with vigorous root systems and high N demand, which prevent N leaching, as well as provides N to the following crop as the straw is mineralized. Sao Paulo State Univ, Coll Agr Sci, Botucatu, SP, Brazil Sao Paulo State Univ, Coll Agr Sci, Botucatu, SP, Brazil FAPESP: 2011/02117-7

The demand for Brachiaria ruziziensis seeds and planting material is increasing in India as it is spreading into new niche areas of silvi-pastoral systems, horti-pastoral systems, mango orchards, and coconut plantations due to its resilience to drought and low light intensities. Brachiaria ruziziensis produces low numbers of pure seeds. In this study, seeds were collected periodically after a single destructive harvest (SDH) and shade drying. Application of irrigation and fertiliser produced a 2.3 fold increase in seed yield compared to the control. However, when seeds were collected through a single destructive harvest (SDH) and shade drying, rather than sweating, the seed qualitative parameters such as seed germination and seed viability improved three and five folds, respectively. Field management techniques such as irrigation and fertiliser application influenced the quantity of seeds produced whereas harvesting methods promoted the quality of seeds produced in B. ruziziensis . Seed germination could also be improved (50%) by treating the seeds with raw cow dung which contains many beneficial microorganisms that produce cellulolytic enzymes, alleviating seed dormancy. Seed yield improved in B.ruziziensis with chemical sprays such as Brassinosteroid 10 ppm (145 kg/ha) and Tryptophan 100 ppm (147 kg/ha) compared to the control, water spray (131 kg/ha). Brassinosteroid sprays could enhance pollen fertility and yield probably through interactions with anther development and sugar metabolism, respectively. Brachiaria ruziziensis produces more vegetative growth in the second year due to its perennial growth habit. The filled seed yield from the second-year crop was 0.8 times less in the control compared to the first year, even with chemical sprays. Perennial plants, in general, maintain their longevity through a physiological trade-off between seed yield and underground growth. Hence, it is beneficial to replant B. ruziziensis every year if grown for seed purposes.

Made available in DSpace on 2018-11-26T17:40:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01 Plants affect soil phosphorus (P) solubility through root exudates, but studies are lacking on species used as relay or cover crops in tropical environments. We evaluated the effect of cover crops on soil phosphorus (P) availability in an oxisol. Ruzigrass (Brachiaria ruziziensis), pearl millet (Pennisetum glaucum), peanut (Arachis hypogaea), crambe (Crambe abyssinica), and sorghum (Sorghum bicolor) were grown in pots with soil. Phosphorus uptake, soil inorganic and organic P, maximum P adsorption capacity, and plant root systems were assessed. When root length density is high, the efficiency of P uptake is low due to root competition. Crambe results in greater soil P availability, while peanut and sorghum decrease the soil maximum P adsorption capacity, probably by exuding or stimulating microbial production of organic acids and phenolic compounds. Hence, crambe, peanut, and sorghum are species that may be of interest to increase P use efficiency in cropping systems. Sao Paulo State Univ, Dept Crop Sci, Coll Agr Sci, CP 237, BR-18601370 Botucatu, SP, Brazil Sao Paulo State Univ, Dept Crop Sci, Coll Agr Sci, CP 237, BR-18601370 Botucatu, SP, Brazil

Background: Carbonaceous shale is one of the common rock types in Malaysia. The most common types of landslides in Malaysia were happened on the cut slope before the construction of highway. Brachiaria ruziziensis and Colopogonium mucunoides were used as the mix vegetation to investigate the effect of chemical amendments on plant growth and root shear strength relationship. Objective: The objective of this study: (1) To investigate the effect of compound fertilizer nitrogen, phosphorus, potassium (NPK), NPK+Ground Magnesium Limestone (GML) (NGL), NPK+GML+foliar fertilizer (Vita-Grow™) (NGF) and control (Ctrl) and (2) To determine the soil shear strength, biomass and root growth. Materials and Methods: The soil samples were analyzed for pH, Total Nitrogen (TN), Soil Organic Carbon (SOC), available phosphorus, exchangeable Al, Ca, Mg and K and trace nutrients (Fe, Mn, Cu and Zn). Results: The carbonaceous shale was low in pH, total N, soil organic carbon, extractable P, basic cations (Ca, Mg and K) and micronutrients (Fe, Cu and Zn). Both P and Ca/Mg were low indicating inherent infertility and chemical constraints for root developments. The dry matter yield, root length and root weight of Brachiaria ruziziensis and Colopogonium mucunoides were increased significantly against NGF treatment. The increased of plant top and root dry weight treated with NGF were 26 and 38%, respectively, compared to the other treatments. The significant root shear strength relationship indicates that root enhanced shear strength by reducing the cohesion and increased the angle of internal friction component. The shear strength analysis from the direct shear test method is to determine the shear strength from the plotted graph. The shear strength analysis showed that NGF treatment was having high shear strength in 5.4, 10.9 and 16.3 and normal stress in 54, 109 and 163 kN m–2. Rapid vegetation growth observed within a 5 months period demonstrated that nutrient and lime application effectively ameliorated chemical constraints to plant growth. Conclusion: The plant mix species treated with NPK+GML+foliar fertilizer (NGF) indicated higher shear strength, dry matter yield and root densities in all layers.

Fresh and conserved pangola grass (Digitaria eriantha Steud., synonym D. decumbens) were compared in terms of in vitro gas production and in vivo nutrient digestibility, metabolisable energy (ME) concentration and average daily gain (ADG) of Thai indigenous cattle. The study was designed as a completely randomised design with Ruzi grass (Brachiaria ruziziensis) as a control and pangola grass in fresh, hay and silage forms at the same age at harvest (45 days regrowth) as treatments. As intended, the dry matter (DM) intake of forages supplemented with concentrate and a protein block was not different (p > .05) among treatments. All forms of pangola ranked higher in crude protein and ME concentrations than Ruzi grass. Pangola silage, to which 5% sugarcane molasses was added at ensiling to minimise the risk of bad fermentation, produced more gas in vitro after 96 hours of incubation and had greater (p

Chiselling has been used to alleviate soil compaction but cover crops with deep, vigorous roots can improve root growth and activity of the cash crop for a longer time. The determination of root activity in addition to root mass or length may improve the understanding of plant response to compaction. The objective of this experiment was to evaluate root growth and activity as affected by the alleviation of soil compaction using mechanical and biological methods. The experiment was conducted in Botucatu, Sao Paulo, Brazil, from 2009 to 2011, on a clay, Typic Rhodudalf soil. Crop rotations including pear millet (Pennisetum glaucum), soybean (Glycine max), grain sorghum (Sorghum bicolor), maize (Zea mays), ruzi grass (Brachiaria ruziziensis) and castor bean (Ricinus communis) in plots, either chiselled or not. Root growth was assessed by core sampling and root activity was determined indirectly using rubidium injected at several depths as a marker. Root activity was instrumental in interpreting the effects of tillage and crop rotations on soil amelioration. Compared with the initial compacted condition, chiselling increased root growth and activity just for the first 18 months of the experiment, but crop rotations, mainly including ruzi grass and castor bean, increased root growth and activity in the soil profile from the second year on. Generally, root mass was poorly correlated with root activity, except in the case of ruzi grass. Introduction of ruzi grass plus castor bean into the cropping system improves not only root growth and activity in the soil profile but also soybean yield.

In Exp. 1, Brachiaria ruziziensis (11.1 % CP) was inoculated or not with two sources of monensin, resulting in three treatments: 1) no monensin inoculation (CONT), 2) 20 mg of monensin sodium-A/kg of DM (Elanco Animal Health; MON-A), and 3) 20 mg of monensin sodium-B/kg of DM (Shandong Qilu King-Phar Pharmaceutical Co. Ltd.; MON-B). Three rumen-fistulated Jersey steers were offered a cool-season forage-based diet and were used as the rumen inoculum donors. Volatile fatty acids concentrations were evaluated at 0, 6, 12, 24, 30, and 48 h after treatment inoculation. Overall, acetate and butyrate concentrations were reduced in MON-A vs. CONT (P ≤ 0.02), whereas both monensin products reduced Ac:Pr ratio vs. CONT (P ≤ 0.01); however, MON-A also (P = 0.05) reduced the Ac:Pr ratio vs. MON-B. A treatment × hour interaction was detected for rumen propionate concentration (P = 0.01), primarily because MON-A resulted in greater propionate than CONT and MON-B at 24 and 48 h (P ≤ 0.03), but no differences were observed between CONT vs. MON-B (P ≥ 0.27). In Exp. 2, 240 Nellore bulls (initial BW = 363.2 ± 40.9 kg) were ranked and blocked according to initial BW, and within blocks animals were allotted into pens (n = 10 pens/treatment). Pens were randomly assigned into one of three treatments: 1) corn-based diet with no monensin (CONT), 2) CONT plus 28 mg of MON-A/kg of DM, and 3) CONT plus 28 mg of MON-B/kg of DM. The CONT diet was composed of sugarcane bagasse, ground corn, DDGS, urea, and a mineral-vitamin mix. The experimental period lasted 106 d and was divided into a 21-d adaptation period and an 85-d finishing phase. During the adaptation phase, both monensin sources increased (P ≤ 0.01) BW change, ADG, and F:G, as well as reduced DMI variation (P = 0.02). When the entire experimental period was evaluated, no treatment effects were detected for final BW, DMI, and ADG (P ≥ 0.26). Nonetheless, DMI variation was reduced as monensin was included (P = 0.01) and only MON-A improved the efficiency by reducing F:G vs. CONT (P = 0.05) and biological efficiency vs. MON-B (P = 0.05). Additionally, carcass ADG tended (P = 0.10) to be greater for MON-A vs. MON-B, whereas no other differences in the carcass characteristics were observed (P ≥ 0.53). In summary, the source of monensin inoculated in vitro and offered to Nellore bulls during the feedlot phase significantly affected the energetic efficiency and the performance of the animals.

The agricultural landscape of French Guiana (Amazonia) is expected to undergo substantial change as a result of rapid population growth in the region. Such changes in the landscape will lead to the conversion of tropical forests into land destined for agricultural use. Little information is available on the effect of different agricultural systems on greenhouse gas (GHG) emissions in French Guiana. For our experiment, two hectares of forest were cleared, without the use of fire, at the Combi experimental site (sandy-clayey Ferralsol) at the end of 2008. After one year with legume and grass cover, the site was modified to include the following three fertilized agricultural systems: (1) Grassland (Brachiaria ruziziensis, mowed), (2) cropland (maize/soybean rotation) with disc tillage, and (3) cropland (maize/soybean rotation) with no-tillage in direct seeding. Soil N2O, CH4, and CO2 fluxes were measured with dark chambers from May 2011 to November 2014. Our results show that grassland was a significantly lower emitter of N2O but a significantly higher emitter of CH4 compared to the two cropland systems studied. We did not observe significant differences between the two cropland systems for N2O and CH4 fluxes. Measurements of the net ecosystem CO2 exchange would be useful to better compare the role of different agricultural systems as a source of GHGs.

Conselho Nacional de Desenvolvimento Científico e Tecnológico A qualidade das sementes é de grande importância para a otimização do estabelecimento de qualquer cultura propagada via sexuada. Dessa forma, a avaliação da qualidade das sementes de forma rápida e não destrutiva traz muitas vantagens para a indústria sementeira, principalmente na tomada de decisão quanto ao descarte de lotes com sementes de baixa qualidade, sendo possível inferir de modo eficaz sobre o vigor das sementes. Assim, métodos rápidos e não destrutivos de avaliação da qualidade de sementes devem ser aprimorados. O objetivo deste trabalho foi propor um método de fenotipagem de alto rendimento a partir do processamento de imagens radiográficas de sementes de melão e braquiária, utilizando software de livre acesso, relacionando os parâmetros obtidos com a qualidade fisiológica das sementes. Foram conduzidos dois experimentos. No primeiro, foram utilizados 30 lotes de sementes comerciais de melão híbrido, 10 lotes das cultivares Bazuca F1, Goldex F1 e Pampa F1, cada. O segundo experimento foi conduzido com sete lotes de sementes comerciais de Brachiaria ruziziensis cv. Ruziziensis. Em ambos os experimentos os lotes de sementes apresentavam diferentes níveis de vigor. O estudo foi realizado por meio da análise automatizada de imagens radiográficas das sementes, em que foi desenvolvida uma macro, denominada PhenoXray, para uso no software ImageJ®. Com esta macro realizou- se o processamento digital das imagens radiográficas das sementes, a partir das quais foram obtidos diferentes descritores morfométricos e de integridade tecidual. As sementes radiografadas para a obtenção das imagens foram, posteriormente, submetidas ao teste de germinação, obtendo-se variáveis relacionadas à sua qualidade fisiológica. Os dados obtidos foram agrupados pelo teste de Scott-knott, submetidos à análise de correlação linear de Pearson e à análise multivariada, por meio de componentes principais. Os resultados demonstraram que a análise automatizada de imagens radiográficas é eficiente para obtenção de dados morfométricos e de integridade tecidual em sementes de melão e Brachiaria ruzizienses; além disso, os parâmetros densidade relativa, densidade integrada e preenchimento apresentaram estreita relação com atributos fisiológicos de qualidade das sementes. Conclui-se que o método de fenotipagem proposto a partir do processamento ode imagens radiográficas utilizando a PhenoXray foi eficiente, apresentando-se como alternativa simples, rápida, robusta e totalmente gratuita. A metodologia também permitiu a obtenção de informações sobre características físicas das sementes e gerar parâmetros capazes de predizer sobre a germinação e o comprimento de plântulas. The seed quality is of great importance for the optimization of the establishment of any crop dispersed by sexual propagation. Thus, fast and non-destructive evaluation of seed quality has many advantages for seed industry, mainly in decision making regarding the discarding of lots with low quality seeds. Also, it enables to infer in an effective way the vigor of the seeds. Thus, rapid and non-destructive seed quality assessment methods should be improved. The objective of this work was to propose a method of high yield phenotyping by radiographic image processing of melon and brachiaria seeds using free access software, and to relate the parameters obtained with the seed physiological quality. Two experiments were conducted. In the first one, 30 commercial seed lots of hybrid melon, 10 lots of each of the following cultivars, were used: Bazuca F1, Goldex F1 and Pampa F1. The second experiment was conducted with seven commercial seed lots of Brachiaria ruziziensis cv. Ruziziensis. In both experiments, the seed lots had different levels of vigor. The study was performed through the automated analysis of the radiographic images, in which a macro, named PhenoXray, was developed for use in ImageJ® software. With this macro, the digital processing of the radiographic images of the seeds was performed, from which different morphometric descriptors and tissue integrity parameters were obtained. The seeds that were radiographed were subsequently submitted to the germination test, from which were obtained variables related to their physiological quality. The data were grouped by the Scott-knott test, submitted to Pearson's linear correlation analysis and to multivariate analysis, using principal components analysis. The results demonstrated that the automated analysis of radiographic images is efficient to obtain morphometric and tissue integrity data of melon and Brachiaria ruzizienses seeds. Among the parameters obtained, relative density, integrated density and fill were closely related to physiological attributes of seeds. It is concluded that the method of phenotyping proposed by processing radiographic images using PhenoXray was efficient. It is a simple, fast, robust and totally free alternative for seed quality assessment. This methodology also allowed to obtain information regarding physical characteristics of the seeds and to generate parameters capable of predicting germination and seedling length.

Objetivou-se avaliar o desempenho agronômico e a dinâmica da água no solo no consórcio milho-braquiária em resposta a diferentes densidades de semeadura da braquiária. Conduziu-se experimento na Fazenda Barbosa, em Brejo, MA. Os tratamentos constaram da combinação de dois híbridos simples de milho (Pioneer 30F 53VYHR e Syngenta Status Viptera 3) e quatro densidades de semeadura da Brachiaria ruziziensis (2, 4, 6 e 8 kg ha-1 de sementes), em consórcio com o milho, bem como ambas as culturas em monocultivo. No milho foram determinados por ocasião da colheita: altura de plantas, altura de inserção de espigas, massa de cem grãos, produtividade de espigas e produtividade de grãos. Na braquiária determinou-se a densidade de plantas, altura de plantas, massa verde e massa seca total. O desempenho do consórcio foi avaliado pelo uso eficiente da terra em cada sistema de cultivo avaliado. Durante o ciclo das culturas, realizou-se a análise de crescimento e o monitoramento da umidade do solo, em duas profundidades (0 a 0,3m e de 0,3 a 0,6 m), com o uso da TDR (Time Domain Reflectometry). Avaliou-se o armazenamento de água no solo em quatro sistemas de cultivo (milho solteiro, braquiária solteira, milho consorciado com braquiária nas densidades de semeadura de 2 e 8 kg ha-1), em quatro períodos de monitoramento. Os tratamentos foram arranjados em parcelas subdivididas, com os sistemas de cultivos nas parcelas e as profundidades de medição nas subparcelas, cujos dados foram submetidos ao teste de Tukey (p

Aims: The objective of this work was to evaluate the agronomic efficiency of the bone meal under acidification in the production of dry matter of Brachiaria ruziziensis in relation to a soluble source. Study Design: The experiment was conducted in a completely randomized design with seven treatments and three replications. Treatments included a control, single superphosphate (SS), bone meal (BM), BM treated with 10% oxalic acid, BM treated with 10% acetic acid, and BM treated with 1% to 0.5% hydrochloric acid. Place and Duration of Study: The experiment was carried out from October 2014 to February 2015, at the Experimental Farm of the Federal University of Rondônia (UNIR), located 15 km from the city of Rolim de Moura, Rondônia, Brazil. Methodology: The bone meal used in the experiment was produced manually, where bovine bones were collected and burned for carbon removal and particle reduction. The oxalic acid, acetic acid and hydrochloric acid were used to increase the solubility of the bone meal for application to the soil for growth of B. ruziziensis. Parameters evaluated were the agronomic efficiency index (AEI), phosphorus conversion efficiency (PCE), shoot dry matter (SDM), and root dry matter (RDM). Results: AEI obtained for acid treatments was above 60% and PCE satisfactory when compared to the soluble source, except for 0.5% hydrochloric acid and significantly above the BM without acid treatments. There was higher production of SDM and RDM with the soluble source (SS), however the acid treatments promoted dry matter production above the BM without acid treatments. Conclusions: The application of acids in bone meal promoted satisfactory agronomic efficiency gains for Brachiaria ruziziensis.

El presente trabajo se desarrolló en los terrenos del fundo Zungarococha (Jardín Agrostologico) – Propiedad de la Facultad de Agronomía-UNAP, ubicado en el caserío de Zungarococha a 45 minutos de la ciudad de Iquitos, con el objetivo de determinar cuatro tiempos de corte y su efecto en la producción (altura, materia verde, materia seca), eficiencia fotosintética y captura de carbono del pasto Ruzzi (Brachiaria ruziziensis). Se utilizó el diseño de Bloques Completos al Azar (DBCA), con tres repeticiones y cuatro tratamientos y prueba de Tukey, con los resultados obtenidos se llegó a las siguientes conclusiones: Que existe un efecto significativo de la edad corte del forraje, en la producción de materia verde y eficiencia fotosintética; mas no así en la captura de carbono en donde podemos observar que la diferencia estadística es mínima en esta última variable estudiada. La edad de corte influencio sobre la eficiencia fotosintética en el pasto Brachiaria ruziziensis. Siendo el tratamiento T3 (corte a la 12ava semana) que tuvo el mejor promedio según el Orden de Mérito (con 4.38%), resultando significativo para los demás tratamientos en estudio. También la edad de corte influencio sobre captura de carbono en el pasto Brachiaria ruziziensis. Siendo el tratamiento T3 (corte a la 12ava semana) que también obtuvo el mejor promedio según el Orden de Mérito (con 0.26 g de C/m2), pero este valor no resulta significativo estadísticamente para los demás tratamientos en estudio. Que el tratamiento más sobresaliente resulto ser el tratamiento T3 (12ava semana de evaluación) ya que tuvo los mejores promedios según el Orden de Mérito tanto para producción de materia verde, eficiencia fotosintética y captura de carbono respectivamente. The present work was developed in the lands of the I found Zungarococha (Garden Agrostology) - Property of the Ability of Agronomy-UNAP, located in the village of Zungarococha to 45 minutes of the city of Iquitos, with the objective of determining four times of court and its effect in the production (height, green matter, dry matter), efficiency fotosintética and capture of carbon of the grass Ruzzi (Brachiaria ruziziensis). the design of Complete Blocks was used at random (DBCA), with three repetitions and four treatments and test of Tukey, with the obtained results you reached the following conclusions: That a significant effect of the age exists it cuts of the forage, in the production of green matter and efficiency fotosintética; but I didn't seize in the capture of carbon where we can observe that the statistical difference is minimum in this last studied variable. The court age influences about the efficiency fotosintética in the grass Brachiaria ruziziensis. Being the treatment T3 (it cuts to the 12ava week) that had the best average according to the Order of Merit (with 4.38%), being significant for the other treatments in study. The court age also influences on capture of carbon in the grass Brachiaria ruziziensis. Being the treatment T3 (it cuts to the 12ava week) that also obtained the best average according to the Order of Merit (with 0.26 g of C/m2), but this value is not significant statistically for the other treatments in study. That the most excellent treatment turns out to be the treatment T3 (12ava week of evaluation) since he/she had the best averages according to the Order of so much Merit for production of green matter, efficiency fotosintética and capture of carbon respectively. Tesis

Livestock production in the lowlands of Eastern Oromia of Ethiopia depends mainly on natural pastures and crop residues which are of poor quality and the yield is generally low during the dry season. Therefore, there is a need to introduce alternative forages of high quality that are adapted to the region. The objective of this study was to identify and select the best Brachiaria grass accession/s for dry matter (DM) yield and nutritive quality in lowlands of Eastern Oromia. The experiment was conducted in the lowlands of Fedis and Dire-Dawa districts during 2018 to 2020. The experimental materials were brachiaria decumbens accessions 1087, 13205, 14721, 14720 and brachiaria ruziziensis accessions 13332, 14743, 14771, 14774, 14813. These grass accessions were compared with one local check, a locally cultivated brachiaria grass. Plant established successfully at both sites for the last three years. Tiller numbers, plant height, forage dry matter yield and plot covers were recorded at 16 weeks after planting. Significant (p

A supressão da forrageira e posterior dessecação da biomassa em sistema de consórcio com milho é fundamental para garantir rentabilidade das culturas. Nesse sentido, o trabalho teve como objetivo avaliar o desempenho do milho consorciado com Brachiaria ruziziensis e tempo de dessecação da biomassa sobre a cultura da soja em sucessão. Foram instalados dois experimentos idênticos na safrinha de 2016 utilizando delineamento experimental de blocos ao acaso com três sistemas de cultivo: milho, milho + braquiária e braquiária, com 16 repetições. Foram avaliados o desempenho das culturas e produção de biomassa. Em sucessão, foi semeado duas cultivares de soja com arquiteturas distintas (NA 7337 RR® com maior capacidade de engalhamento e ANTA 82 RR® sem essa característica) utilizando delineamento experimental de blocos ao acaso, com quatro repetições, em arranjo fatorial 3x4, sendo três sistemas de cultivo (milho, milho + braquiária e braquiária) e quatro épocas de dessecação (0, 7, 14 e 21 dias antes da semeadura da soja (DAS)). Nestes experimentos foram avaliados o desempenho agronômico da soja. Os resultados obtidos mostraram que a braquiária em consórcio com o milho não reduz a produtividade da cultura desde que o solo apresente adequada fertilidade. Para a cultivar Anta 82 RR®, recomenda-se efetuar o manejo da dessecação em torno de 15 DAS para o cultivo milho e milho + braquiária e 23 DAS para o sistema somente com braquiária. A cultivar NA 7337 RR® demonstrou ser mais interessante para ser cultivada em sucessão a braquiária (em consórcio ou isolada).