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The stud article aimed to assess the accumulation and rates of nutrients in the biomass of the consortium of millet and leguminous plants for green fertilisation. The treatments were consortia of millet with four different leguminous plants: Cajanus cajan, Canavalia ensiformis, Mucuna aterrima, and Dolichos lablab. The treatments were distributed in a completely randomised design with four replications. The species of each consortium were planted in a line, at a distance of one metre apart. The aerial part of the plants was harvested after 90 days to determine the botanical composition, intercropping biomass, and the amount and accumulation of macronutrients in the biomass. The Millet mass did not differ among the consortia. However, among the legumes, M. aterrima has the highest mass (2806.31 kg/ha DM), which is reflected in the lower ratio of leguminous grasses in the millet consortium with M. aterrima (4.61). The consortia affected the rate and accumulation of P, B, and Fe. The biomass of the millet consortium with C. cajan presented the lowest rate. In addition, the accumulation of K, Mg, and Zn was low in this consortium. The biomass of millet intercrops with M. aterrima, D. lablab and C. ensiformis showed higher accumulations of K, Ca, and Mg. The highest accumulation of N was observed in the biomass of the consortium with M. aterrima (50.71 kg/ha). The rates and accumulations of Cu and Zn were higher in the consortium with M. aterrima. The consortium of millet with the leguminous plants is a sustainable alternative for fertilisation. The consortia with M. aterrima and D. lablab are the most promising ones, due to the higher proportion of plants. Made available in DSpace on 2022-09-26T12:07:47Z (GMT). No. of bitstreams: 1 Intercrops-of-grass-with-legumes-as-green-manure-for-agroecological-systems.pdf: 435873 bytes, checksum: 008661efd892111368fa303762807db6 (MD5) Previous issue date: 2022

Forage peanut (Arachis pintoi) is considered a legume ideotype for use in mixed pastures in humid tropical regions, but its adoption has been hindered by low availability and high prices of commercial seeds. However, there is a concern if breeding of high seed-yielding cultivars could result in loss of compatibility with grasses. This study compared the competitive ability and spreading ability of 12 forage peanut genotypes with contrasting seed-yielding potential in mixtures with Brachiaria humidicola in northern Brazil. These genotypes were previously selected for high performance under clipping in pure stands. Twenty-five rooted stolons of forage peanut were transplanted to the central area (1 × 1 m) of each plot (5 × 5 m) seeded 35 days before with B. humidicola. The experiment used a randomized complete block design with five replicates per genotype and was evaluated under grazing from 6 to 30 months after pasture establishment using the intermittent stocking method. All genotypes persisted and increased their proportion in botanical composition over time. Spread of forage peanut stolons into surrounding B. humidicola sward varied from 0.56 to 1.46 m/year. Cultivar BRS Mandobi had the greatest competitive ability and cultivar Belomonte the greatest spreading ability. Two genotypes (cv. BRS Mandobi and accession BRA-00064752-9) were selected combining high seed-yielding and high compatibility with B. humidicola. This is evidence that both traits (compatibility with grasses and seed yield) can be simultaneously improved in this legume. The results are discussed in terms of the ecology of grass-legume mixtures and breeding of forage peanut. Made available in DSpace on 2021-11-24T15:00:58Z (GMT). No. of bitstreams: 1 27231.pdf: 944492 bytes, checksum: 03f8b704a1a014bc3b79634eb8c127ca (MD5) Previous issue date: 2021

Forage grasses cultivation in production system with soybean and maize is an alternative to improve tropical weathered soils quality in Brazil. The aim of the study was to evaluate the effects in the production systems involving cultivation of Urochloa brizantha cv. Piatã, in monoculture or in succession with soybean and maize crops, on organic matter and structuring of soil in Brazilian savanna. The experiment was implemented in the 2010/2011 season. The treatments consisted of nine production systems and a native forest (savanna) as a reference area. In March 2017, soil sampling was carried out for C and N analysis, physical and chemical fractionation of SOM and aggregate stability. Production systems influenced total organic carbon (TOC) and aggregate stability, mainly in the surface layers, leading to changes in SOM quality. TOC was 31% lower in monoculture soybean production system, when compared to native savanna area, in the 0.00?0.20 m layer. The agricultural production systems influence organic matter quality and soil aggregates stability. For the Brazilian savanna conditions, grain cultivation systems under no-tillage that integrate Urochloa brizantha cv. Piatã contribute to the soil quality improvement. Soybean monoculture generally provides worse soil quality indices compared to other agricultural production systems. Made available in DSpace on 2022-07-13T13:19:36Z (GMT). No. of bitstreams: 1 Soil-organic-matter-and-aggregate-stability.pdf: 893257 bytes, checksum: de19f838d04dfb26ebf3d86448e0cef5 (MD5) Previous issue date: 2022

This study aimed to evaluate the physiological parameters and the biomass flow and structural characteristics of BRS Massai and BRS Tamani grasses under different irrigation conditions. The rating of gas exchange, biomass flow and structural characteristics were performed in dry periods and dry/rainy season, under the water supply of 30; 60; 90 and 120% of the reference evapotranspiration (ETo). The experimental design was completely randomized in a factorial arrangement 4x2 (water supply and grass). The experiment was conducted in pots with capacity for 7.5 dm³, using as substrate layer of 0-0.2 m soil. There was no effect (P < 0.05) between the gas exchange in the dry period, having the largest growing parameters of irrigation schemes. In the transition period of dry/rainy, we observed a reversal behavior in relation to the dry period, showing a rapid recovery of grasses under the minor water supply. It was observed quadratic behavior to concentrations of CO2 in the leaf mesophilic (Ci) with maximum point to the BRS Massai grass and minimum point to the BRS Tamani grass, where the major and minor Ci were 119 and 48 ppm in the water supply of 107 and 35% of ETo, respectively. In relation to the biomass flow, the BRS Tamani grass presented greater stem elongation rate and leaf senescence rate in relation to BRS Massai in both periods assessed. In the dry period, we observed a higher biomass production of green leaf blades in the BRS Tamani grass, while in the transition dry/rainy season, the results for this variable were similar, and at the same time that observed higher accumulation of green culm biomass to the BRS Tamani grass, which certainly affected its structure. It is concluded that the application of a minimum daily water supply of 30% of ETo allows the maintenance of BRS Massai and BRS Tamani grasses without incurring the death of tillers and reduction of regrowth vigor, whereas the water supply of 90% of ETo favors the morphophysiological characteristics, especially of BRS Tamani grass. [Morfofisiologia de gramíneas tropicais sob diferentes regimes hídricos em duas estações de crescimento: II. capins BRS Massai e BRS Tamani]. Resumo: Objetivou-se avaliar os parâmetros fisiológicos, as características morfogênicas e estruturais dos capins BRS Massai e BRS Tamani sob diferentes condições hídricas. As avaliações de trocas gasosas, do fluxo de biomassa e das características estruturais foram realizadas nos períodos seco e de transição seca/ águas, sob os regimes de lâminas de irrigação de 30; 60; 90 e 120% da evapotranspiração de referência (ETo). Utilizou-se o delineamento inteiramente casualizado em arranjo fatorial 4x2 (lâminas de irrigação e gramíneas). O experimento foi conduzido em vasos com capacidade para 7,5 dm³, utilizando como substrato a camada de 0-0,2 m do solo. Houve efeito (P < 0,05) entre as trocas gasosas no período seco, onde os crescentes regimes de irrigação proporcionaram melhores resultados. No período de transição seco/chuvoso observou-se uma inversão de comportamento em relação ao período seco, evidenciando rápida recuperação das gramíneas sob os menores tratamentos de irrigação. Observou-se comportamento quadrático para variável concentrações de CO2 no mesófilo foliar (Ci), com ponto de máximo para o capim massai e de mínimo para o capim-tamani, onde as maiores e menores Ci de 119 e 48 ppm nas lâminas de irrigação de 107 e 35% da ETo, respectivamente. No tocante ao fluxo de biomassa, o capim-tamani apresentou maior taxa de alongamento das hastes e de senescência foliar em relação a cultivar BRS Massai em ambos os períodos avaliados. No período seco, observou-se maior produção de biomassa de lâminas foliares verde no capim-tamani, enquanto que no período de transição seca/águas, os resultados para esta variável foram semelhantes, ao mesmo tempo em que se observa maior acúmulo de biomassa de colmo verde no capim-tamani, o que afetou sua estrutura. Conclui-se que a aplicação de uma lâmina mínima diária de 30% da ETo possibilita a manutenção das gramíneas BRS Massai e BRS Tamani sem incorrer em morte de perfilhos e redução do vigor de rebrotação, ao passo que a lâmina de 90% da ETo favorece as características morfofisiológicas, em especial do capim-tamani. Made available in DSpace on 2021-08-04T12:04:26Z (GMT). No. of bitstreams: 1 CNPC-2021-Art-13.pdf: 486559 bytes, checksum: 929bf3fb3ded6ca0719c3d55c68c130d (MD5) Previous issue date: 2021

Adequate potassium (K) fertilization is essential for agricultural production in soils of the Brazilian Savanna (Cerrado biome) due to the high demand by crops (especially cotton), likelihood of leaching losses, and the dependence on fertilizer importations. Therefore, sustainability requires improvements in the soil efficiency management. This study evaluated the influence of soil management and crop succession or rotation combinations with cotton on K dynamics and exchangeable reserves in the soil profile, and the partial balance of K after nine years of cultivation in a clayey Oxisol in the Cerrado. The soil was sampled in layers up to 100 cm depth in four cotton production systems treatments: 1) conventional soil tillage (CST) with cotton monoculture; 2) CST with annual cotton-soybean-cotton succession; 3) CST with cotton/soybean/maize rotation; and 4) no-tillage system (NTS) with cotton/soybean/maize rotation and Urochloa ruziziensis (ruzigrass) as a cover crop in the off-season after grain crops. The experiment was conducted using a randomized block design with four replications. CST with cotton monoculture favored the leaching of K surplus from fertilization. Crop rotation including ruzigrass in the NTS allowed better control of K dynamics, ensuring its circulation in the soil-plant compartments and reducing leaching. The increased organic matter (OM) in this system enlarges the storage capacity of K in the topsoil. The adoption of no-tillage crop systems integrating ruzigrass is viable to improve the efficiency of K fertilizers in cotton cultivation in highly weathered tropical soils. Made available in DSpace on 2021-08-26T02:06:32Z (GMT). No. of bitstreams: 1 Exchangeable-potassium-reserve.pdf: 945319 bytes, checksum: 12bd4d45abb01fd87ac85affcd27d3b1 (MD5) Previous issue date: 2022

We aimed to measure the efficiency of visual selection of plant vigor for green biomass production of U. ruziziensis using single- and multitrait approaches to maximize the predictive accuracy of the genetic value. The green biomass production and plant vigor of 254 U. ruziziensis clones were measured over nine evaluation cuttings to determine the efficiency of these approaches for production improvement. Individual and multicutting analyses were performed under single-trait and multitrait approaches using mixed models. The efficiency of visual selection was assessed by measuring plant vigor based on direct and indirect genetic gains. Plant vigor showed a high genetic association with green biomass and could be selected for production, especially in the initial phases of breeding programs. The multitrait approach was superior to the single-trait approach in predicting the genetic value of the clones, and it can be used in U. ruziziensis breeding programs. Made available in DSpace on 2022-08-25T18:19:22Z (GMT). No. of bitstreams: 1 Efficiency-of-indirect-selection-for-green-biomass.pdf: 397687 bytes, checksum: ec35d48775bd35e36079a87ccdddb536 (MD5) Previous issue date: 2022

Prolonged storage of seeds may lead to decreases in seed quality, negatively affecting germination and vigor and preventing the obtaining of a promising stand. Seed quality is a critical factor, and the performance of the lot can be altered by vigor, dormancy and, mainly, by the time and conditions in which the seeds were stored. In the experiment, the physiological quality of seeds 14 genotypes of buffel grass (Cenchrus ciliaris L.) genotypes stored for a period of thirteen years in cold conditions was evaluated. The seeds were subjected to germination induction treatment with potassium nitrate (KNO3) and evaluated to identify seeds with presence and absence of embryos. The seed storage period affected their germination capacity and the use of KNO3 did not increase seed germination. A low number of full seeds was found for genotype 613 (12%). The relative germination percentages did not underestimate the buffel grass seed germination potential, as it is usually calculated, providing an improved distinction between the evaluated genotypes. The use of KNO3 increased the seedling root and shoot weights of some genotypes, as well as the dry matter weight of seedlings, an important characteristic for forage production. The prolonged storage affects the physiological quality of buffel grass seeds. The production of seeds without embryo is a problem found for this species, which affects the final quality of the seed lots produced. Resumo: O armazenamento prolongado pode levar a perda da qualidade das sementes, influenciando negativamente na germinação e vigor e impedindo a obtenção de um estande promissor. A qualidade das sementes é um fator crucial, e o desempenho do lote pode ser alterado pelo vigor, dormência e principalmente, pelo tempo e condições em que as sementes ficaram armazenadas. No experimento foi avaliada a qualidade fisiológica de sementes de 14 genótipos de capim-bufel (Cenchrus ciliaris L.) armazenados por treze anos em câmara fria. As sementes foram submetidas a tratamento para indução da germinação com nitrato de potássio (KNO3), e posteriores avaliações para identificação da presença e ausência de embrião. O período em que as sementes ficaram armazenadas afetou sua capacidade de germinação e o KNO3 utilizado não induziu aumento na germinação das sementes. Baixo número de sementes cheias foi verificado para o genótipo 613 (12%). As porcentagens de germinação relativa não subestimaram o potencial de germinação das sementes de C. ciliaris, como usualmente é calculada, fornecendo distinção melhorada entre os genótipos avaliados. O KNO3 incrementou positivamente nas partes das plântulas de alguns genótipos, bem como na biomassa seca destas, sendo uma característica importante para a forragicultura em geral. O armazenamento prolongado afetou a qualidade fisiológica das sementes de C. ciliaris. A produção de sementes sem embrião é um problema encontrado nessa espécie, interferindo na qualidade final dos lotes produzidos.

This study aimed to evaluate the physiological parameters, the productive characteristics, structural and chemical composition of Megathyrsus maximus (syn. Panicum maximum) cultivars BRS Massai and BRS Tamani submitted to different periods of deferment and moments of use. The experimental design was randomized complete block design in a factorial scheme 2 x 2 x 3, being two grass cultivars (Massai grass and Tamani grass), two deferment periods (rainy season and dry-rainy transition) and three sealing times (40, 80 and 120 days). Both cultivars had higher leaf transpiration rate when used for 40 days of deferment (0.63 μmol/m2/s). It was observed that the cultivar BRS Massai presented higher photosynthetic rate (P

Spittlebugs are among the main insect pests of forage grasses in Brazil. In February 2021, a spittlebug infestation was verified in Xaraés palisadegrass (Brachiaria brizantha cv. Xaraés) in the municipality of Senador Guiomard, Acre state, Brazil. The specimens were captured with an entomological sweep net and identified as Notozulia entreriana (Berg) and Mahanarva spectabilis (Distant) (Hemiptera: Cercopidae). Notozulia entreriana is frequently captured in studies with spittlebugs in Acre state, though this is the first record of M. spectabilis in the state. This new record expands the species known geographical distribution in Brazil and the number of species of Mahanarva occurring in Acre state. Made available in DSpace on 2021-10-25T15:00:23Z (GMT). No. of bitstreams: 1 27216.pdf: 563387 bytes, checksum: ca4b79e0e63db7608f2adc5138c09b51 (MD5) Previous issue date: 2021

Cattle production is one of the main economic activities in the state of Roraima, and insect pest attacks in pastures have a negative effect on this sector in the region. Little is known about the species that cause damage to forage fields in the state. This study presents the first report of the occurrence of the chinch bug Blissus pulchellus Montandon (Hemiptera: Blissidae) in Roraima, Brazil and a description of the population dynamics of this pest in pasture areas in this state. Pasture areas were sampled in nine municipalities of Roraima to detect the insect. The population dynamics study was conducted for two years in Alto Alegre municipality, two of which have Brachiaria brizantha cv. Marandu and one of Megathrysus maximus cv. Mombaça (Poaceae) crops. Blissus pulchellus was found in all sampled areas, except in Rorainópolis and São João da Baliza. High densities of this bug were found in in Alto Alegre. This is the first report of B. pulchellus in Brazil. The factors that affect the population dynamics and the damage caused by this insect pest to pastures as well as the risk of dispersal of this pest in Brazil are discussed. Made available in DSpace on 2021-08-04T18:00:22Z (GMT). No. of bitstreams: 1 Elisangela-first-occurrence.pdf: 3635711 bytes, checksum: f3f21f629cd0afcb5a6f2f26e5845a10 (MD5) Previous issue date: 2021

Aiming to compare integrated crop, livestock (ICL) and forest (ICLF) systems in relation to ingestive behavior of dairy heifers, a 2 × 2 crossover trial was conducted with two periods and two systems. Eight Girolando (3/4holstein × 1/4 Gyr) heifers were evaluated in pasture of Xaraés palisade grass (Urochloa brizantha 'Xaraes' syn Brachiaria brizantha) managed with intermittent stocking. The ICLF systemhad eucalyptus trees planted in tiers with 65% crown cover. Ingestive behavior parameters were obtained using acoustic data collected with mP3 recorders for 48hours. Statistical analysis was performed using the mixed procedure of SAS, and means were compared using the Tukey-Kramer test at 5% significance. The dry mater intake (DMI), number of daily grazing sessions, and the duration of the grazing sessions did not differ (P

This study aimed to evaluate the physiological parameters, the productive characteristics, structural and chemical composition of Urochloa Brizantha cultivars BRS and BRS Piatã submitted to two deferment periods and three using times. The experimental design was randomized complete block design in a factorial scheme 2 x 2 x 3, being two grass cultivars (Paiaguás grass and Piatã grass), two deferment periods (rainy season and dryrainy transition) and three sealing times (40, 80 and 120 days). It was observed that, in the rainy season, the grasses had higher leaf transpiration rate when used for 40 days of deferment (1.66 ?mol m2/s). During the rainy season, the Stomatal conductance was detected only in the grasses used with shorter seal, with an average of 0.07 ?mol m2/s. In contrast, in the period of transition, the concentration decreased to 0.02 ?mol m2/s. In a general way, the BRS Paiaguás presented lower content of NDF. The shorter cycle provided greater biomass production of total forage during the period of rain, approximately 2.78 times more than the same pasture grass deferred during the transition period. Generally, the periods of deferment and moments of use cause effects on structural characteristics of pasture, being that the period of deferment of the transition period and used for 40 and 80 days may be a strategy for keeping animals in critical periods. [Trocas gasosas, características produtivas e composição química de gramíneas tropicais diferidas II: cultivares BRS Paiaguás e BRS Piatã]. Resumo: Objetivou-se avaliar os parâmetros fisiológicos, as características produtivas, estruturais e composição química da Urochloa Brizantha cultivares BRS Paiaguás e BRS Piatã submetidos a dois períodos de diferimento e três momentos de utilização. Utilizou-se o delineamento de blocos completos casualizados, em esquema fatorial 2 x 2 x 3, sendo duas cultivares de gramíneas (capim-paiaguás e capim- piatã), dois períodos de diferimento (período chuvoso e transição chuvoso-seco) e três tempos de vedação (40, 80 e 120 dias). Observou-se que, dentro do período chuvoso, as gramíneas tiveram maior taxa de transpiração foliar quando utilizadas aos 40 dias de diferimento (1,66 ?mol m2/s). Neste mesmo período, a condutância estomática foi detectada somente nas gramíneas utilizadas com menor tempo de vedação, apresentando média de 0,07 ?mol m2/s. Em contrapartida, no período de transição, a concentração diminuiu para 0,02 ?mol m2/s. De forma geral, a cultivar BRS Paiaguás apresentou menor teor de FDN. O menor tempo de vedação proporcionou maior produção de biomassa de forragem total durante o período da chuva, cerca de 2,78 vezes mais forragem que o mesmo pasto diferido durante o período de transição. De modo geral, ambos os períodos de diferimento e tempos de vedação causam efeitos nas características estruturais da pastagem, sendo que o diferimento no período de transição por um tempo de 40 e 80 dias pode ser uma estratégia para manutenção dos animais em períodos críticos. Made available in DSpace on 2021-08-04T13:00:39Z (GMT). No. of bitstreams: 1 CNPC-2021-Art-14.pdf: 3695715 bytes, checksum: e481a0e3e91429f0dc8226bfd723a237 (MD5) Previous issue date: 2021

The aim of this study was to evaluate the chemical composition, digestibility, gas production kinetics and in vitro methane (CH4) production of Urochloa brizantha cv. Marandu under two stocking methods over three consecutive stocking cycles. The stocking methods were (1) a fixed-time stocking cycle of 33 days (33-SC) with a 30-day rest period and a 3-day grazing period, and (2) a variable stocking cycle, with the end of the rest period when the canopy intercepted 95% of the light and a 3-day grazing period (95-LI). The average rest period was 24.5-day (standard deviation of 5.2-day) for 95-LI. The in vitro dry matter digestibility (IVDMD) was higher (p < .01) for 95-LI (646 g/kg) relative to 33-SC (628 g/kg). Crude protein concentration was higher (p < .01) for 95-LI (154 g/kg) relative to 33-SC (136 g/kg). The ADF (303 g/kg DM) and aNDF (623 g/kg) were higher (p < .01) for 33-SC compared to 95-LI (287 and 605 g/kg respectively). The gas production potential from non-fibrous carbohydrates was 9.4% higher for 33-SC. The in vitro CH4 production per unit of degraded dry matter (DDM) was higher (p < .01) for 33-SC (19.9 CH4 ml/g), compared to 95-LI (17.9 CH4 ml/g). The 33-SC management resulted in rest periods that were too long for the time needed for optimal regrowth. The variable SC based on the 95-LI was more favourable, because it resulted in maximum yield of dry matter with improved forage nutritive value, while decreasing CH4 yield. Made available in DSpace on 2021-09-24T12:00:27Z (GMT). No. of bitstreams: 1 Nutritive-value-in-vitro.pdf: 685130 bytes, checksum: c7339a38b9d8ea774945c3306e5b3ed5 (MD5) Previous issue date: 2021

The physiological quality of seeds is influenced by the climatic factors of production fields. The identification of the best conditions of P. maximum cv. Mombasa production fields allows the improvement of the seed sector. The aim of this work was to identify which climatic conditions of production fields can affect the physiological quality of P. maximum cv. Mombasa seeds. Nineteen plots from states of São Paulo (six from municipalities of Auriflama and three from Guzolândia) and Goiás (eight from Quirinópolis and two from Serranópolis), were collected by soil sweeping. The following parameters were evaluated: water content, germination rate, first germination count and germination rate index, seedling emergence in sand and field. Completely randomized design was used for all variables, with the exception of seedling emergence in field, since this variable required block design. Means were compared by the Scott-Knott test, at 5% probability. For the identification of the influence of climatic conditions on the physiological quality of seeds, multivariate statistical analysis was applied through Group and Principal Component Analysis. Production fields of Panicum maximum cv. Mombasa seeds presenting maximum temperatures above 32 ºC at flowering and natural fall stages produce seeds of low physiological quality. Production fields in which precipitation and high temperatures occur during natural fall and harvest of P. maximum cv. Mombasa seeds are not favorable to the production of seeds with high physiological quality. A qualidade fisiológica das sementes é influenciada pelos fatores climáticas dos campos de produção. A identificação das condições dos melhores campos de produção de P. maximum cv. Mombaça permite aprimoramento do setor de sementes. O objetivo desse trabalho foi identificar quais condições climáticas dos campos de produção podem afetar a qualidade fisiológica das sementes de P. maximum cv. Mombaça. Foram avaliados dezenove lotes procedentes do estado de São Paulo (seis de Auriflama e três de Guzolândia) e Goiás (oito de Quirinópolis e dois de Serranópolis), colhidos por varredura do solo. Foram avaliados por meio dos seguintes parâmetros: teor de água, germinação, primeira contagem de germinação e índice de velocidade de germinação, emergência de plântulas em areia e em campo. Adotou-se delineamento inteiramente casualizado para todas as variáveis, com exceção da emergência de plântulas em campo, pois neste adotou-se delineamento em blocos. As médias foram comparadas pelo teste Scott-Knott, a 5% de probabilidade. Para a identificação da influência das condições climáticas na qualidade fisiológica das sementes aplicou-se análise estatística multivariada por meio de Análise de Agrupamento e Componentes Principais. Campos de produção de sementes de Panicum maximum cv. Mombaça que apresentam temperaturas máximas superiores a 32 ºC nas épocas de florescimento e degrana produzem sementes de baixa qualidade fisiológica. Campos de produção em que ocorram precipitações e altas temperaturas durante a degrana e à colheita de sementes de P. maximum cv. Mombaça não são favoráveis a produção de sementes com alta qualidade fisiológica.

Our objective was to compare herbage accumulation and nutritive value of Urochloa decumbens (Stapf) R. Webster managed under pre-grazing canopy light interception (LI) targets of 90%, 95% and 100% in silvopastoral system (SPS) and 95% in open pasture (OP; U. decumbens under full sunlight) to establish a pre-grazing target for SPS of ~43% shade. The evaluations were made during two rainy seasons and one dry season. The total herbage accumulation in SPS was lower than in OP at all LI targets and seasons. However, the difference in total herbage accumulation between SPS and OP was reduced when SPS was harvested at 95% LI, with reductions of 20% and 28% in both rainy seasons (12,191 × 15,324 kg DM/ha and 11,158 × 15,424 kg DM/ha respectively). Moreover, under 95% LI in SPS, crude protein concentration was 18% and 19% greater than that in OP in both rainy seasons (155 × 131 g/kg DM and 144 × 121 g/kg DM respectively), thus representing the optimal pre-grazing LI target for U. decumbens in SPS. In addition, a canopy height of 20 cm was necessary for 95% LI in OP and a height of 40 cm in SPS. Therefore, U. decumbens should be grazed at 40 cm canopy height, in SPS with ~43% shade to keep 95% LI as the target. However, this target will only be effective if the shade level is maintained, which will reduce height variation over time. Made available in DSpace on 2021-09-26T02:02:45Z (GMT). No. of bitstreams: 1 Grazing-management.pdf: 1544913 bytes, checksum: 30a40f16f786643001a461fc8bfc4a59 (MD5) Previous issue date: 2020

The aim of this study was to evaluate the effects of plant growth-promoting rhizobacteria effects on anatomical characteristics and nutritional value of Brachiaria (Syn. Urochloa) brizantha cv. BRS Piatã. The experimental design applied was completely randomized design with three treatments: (1) non-inoculated unfertilized-control plants (C-), (2) non-inoculated fertilized-control plants (C+) and (3) B. brizantha inoculated with Pseudomonas fluorescens (BRM-32111) and Burkholderia pyrrocinia (BRM-32113). The following parameters were evaluated at 35 days after seedling emergence: biomass production, plant height, net photosynthesis (A), water-use efficiency (WUE), chlorophyll (SPAD), anatomical and nutritional. The rhizobacteria modified the anatomy of the leaf, culm and roots of B. brizantha. They also increased the chlorophyll content, A, WUE, total soluble carbohydrates, starch and crude protein contents, N, P, Mg and Fe concentrations, plant height, root area and biomass production. Therefore, we conclude that co-inoculation with P. fluorescens (BRM-32111) and B. pyrrocinia (BRM-32113) modified the anatomy and biochemistry of B. brizantha, promoting growth and nutrient accumulation. Therefore, these findings set up the basis for additional exploratory studies, using these rhizobacteria as biotechnological innovation with potential of use as biofertilizer in B. brizantha, aiming higher productivity and nutritive value in a more eco-friendly and sustainable pasture production system. Made available in DSpace on 2020-02-29T00:36:05Z (GMT). No. of bitstreams: 1 16077590281PB.pdf: 842800 bytes, checksum: 6e5ecbbe9b57a90462c8a1cb9fd6825f (MD5) Previous issue date: 2020

Compreender as respostas da vegetação à herbivoria têm sido um dos focos na ecologia de plantas nas últimas décadas. Estas estão ligadas a fatores tais como a intensidade e frequência de desfolha, bem como respostas espécie específicas. Dentro de ambientes pastoris heterogêneos, como os Campos presentes no bioma Pampa, essas respostas podem ser um indicativo do funcionamento individual das espécies. O presente experimento foi conduzido na Estação Experimental Agronômica da Universidade Federal do Rio Grande do Sul (EEA-UFRGS), dentro de um protocolo experimental de longa duração (desde 1986) caracterizado pela utilização de diferentes níveis de oferta de forragem de uma pastagem natural característica do Bioma Pampa. O objetivo do presente trabalho foi definir as respostas de plantas de Andropogon lateralis Nees., espécie altamente representativa do estrato superior de plantas destas pastagens, com base em características funcionais (altura das touceiras, projeção da copa e perímetro da base), bem como definir, através de análise de agrupamento, grupos de touceiras de A. lateralis com características similares. As ofertas de forragem aqui utilizadas foram fixas 8%, 12% e 16% (kg de matéria seca para 100 kg de peso vivo animal), além de uma variável 8-12% (8% na primavera e 12% nas demais estações do ano). Foi utilizado método de pastoreio contínuo e o delineamento experimental de blocos casualizados (com 4 tratamento e duas repetições cada) com medidas repetidas no tempo, sendo o fator de bloqueamento os diferentes tipos de solos do experimento. Para as medições utilizou-se dez touceiras por unidade experimental onde as amostragens dos caracteres acima citados foram repetidas ao longo cinco meses (de março a julho, sendo uma medição por mês). Nossos resultados indicam que as touceiras apresentaram um padrão de diminuição das dimensões altura e projeção da copa conforme passamos do final do verão até inverno, enquanto o perímetro da base apresenta comportamento inverso. Análises de grupamento indicaram a formação de dois grupos para o primeiro período enquanto que para os demais períodos houve a formação de três grupos distintos. Este trabalho nos traz novos indicativos de como a relação planta-animal se manifesta no Campos Sulinos, onde respostas na estrutura de Andropogon lateralis (altura e projeção da copa) são função direta da OF empregada. Understanding vegetation responses to herbivory has been a focus in plant ecology in recent decades. These are linked to factors such as the intensity and severity of defoliation, as well as specific species responses. Within heterogeneous pastoral environments, such as the Campos in the Pampa biome, responses may be indicative of the individual functioning of the species. The experiment resulting in this work was carried out at the Agricultural Experimental Station of the Federal University of Rio Grande do Sul (EEA-UFRGS), within a long-term experiment (since 1986) characterized by the use of different levels of forage allowance in a characteristic natural pasture of the Pampa Biome. The objective of the present work was to define the responses of Andropogon lateralis Nees., a representative upper strata plant species of these pastures, based on functional traits (tussocks height, canopy projection and basal perimeter), as well how to define, through cluster analysis, groups of plants with similar characteristics. The forage allowances used here were fixed 8%, 12% and 16% (kg of dry matter for 100 kg of live animal weight), in addition to a variable 8-12% (8% in spring and 12% in other seasons of the year). Grazing method was continuous stocking, and the experimental design used was randomized blocks (with 4 treatments and two repetitions) with repeated measures over time. The blocking factor was different soil types. For the measurements, ten tussocks per experimental unit were used where the sampling of the characters mentioned above were repeated over five months (from March to July, one measurement per month). Results indicate that tussocks showed decreasing pattern in height and canopy projection as we went from late summer to winter, while basal perimeter showed the opposite behavior. Cluster analyzes indicated the formation of two groups for the first period, while for the other periods there was the formation of three distinct groups. This work brings us new indications of how the plant-animal relationship manifests in Campos Sulinos, where responses in the structure of Andropogon lateralis (height and canopy projection) are a direct function of the FA employed.

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 knowledge of gas exchanges in forage plants is essential for a better understanding of the process of forage biomass production in pasture. This study evaluated the gas exchange in massai grass fertilized with increasing levels of nitrogen fertilizer (control - without nitrogen fertilizer; 400; 800 and 1200 kg ha-1 year-1) and under rotational grazing by sheep, in a completely randomized design with repeated measures in time. The rest period was approximately 1.5 new leaves per tiller, as determined in the pre-test at the beginning of the experiment, providing interval of 22; 18; 16 and 13 days for the levels 0.0 - control; 400; 800 and 1200 kg ha-1 year-1 nitrogen, respectively. The animals used to lower the sward height to the recommended residual height were sheep (½ Morada Nova x ½ undefined breed), placed in paddocks of 42.3 m2. As the animals grazed, the height of the sward was monitored with a ruler until the canopy reached the recommended residual height of approximately 15 cm, corresponding to the residual LAI of exit of the animals from the paddock at approximately 1.5, as determined in a pre-test to set up the experiment. The variables stomatal conductance, leaf photosynthesis rate, leaf carbon dioxide concentration, photosynthesis/transpiration ratio, chlorophyll relative index and nitrogen sufficiency index revealed a positive linear response to nitrogen fertilization. Nitrogen fertilization level at 1200 kg ha-1 year-1 caused an increment of 92.3% in leaf photosynthesis rate in relation to the control. The leaf temperature and photosynthesis/conductance ratio were reduced with increasing nitrogen levels. The leaf transpiration showed a quadratic response with maximum point with increasing nitrogen levels. Nitrogen fertilization favor the gas exchange in massai grass up to the last level tested. O conhecimento das trocas gasosas em plantas forrageiras é essencial para melhor entendimento de como ocorre o processo de produção de biomassa de forragem na pastagem. Objetivou-se avaliar as trocas gasosas no capim-massai submetido a crescentes doses de nitrogênio (controle - sem nitrogênio; 400; 800 e 1200 kg ha-1 ano-1) e sob lotação rotativa com ovinos, num delineamento inteiramente casualizado com medidas repetidas no tempo. O período de descanso adotado foi de aproximadamente 1,5 novas folhas por perfilho, conforme determinação em pré-ensaio quando do início da instalação do experimento, propiciando um intervalo de 22; 18; 16 e 13 dias para as doses 0,0 – controle; 400; 800 e 1200 kg ha-1 ano-1 de nitrogênio, respectivamente. Os animais utilizados para rebaixamento do pasto até a altura residual preconizada foram ovinos (½ Morada Nova x ½ SPRD), alocados em piquetes de 42,3 m2. À medida que os animais pastejavam, a altura do pasto foi monitorada com auxílio de uma régua, até que o dossel atingisse a altura residual preconizada de aproximadamente 15 cm, correspondendo ao IAF residual de saída dos animais do piquete de aproximadamente 1,5, conforme determinação em pré-ensaio para instalação do experimento. As variáveis: condutância estomática, taxa de fotossíntese foliar, concentração interna de CO2, relação fotossíntese/transpiração, índice relativo de clorofila e índice de suficiência de nitrogênio responderam de forma linear crescente ao incremento nas doses de nitrogênio. Verificou-se aumento de 92,3% na taxa de fotossíntese para a dose de N de 1200 kg ha-1 ano-1 em relação à ausência de nitrogênio. A temperatura da folha e a relação fotossíntese/condutância foram reduzidas com o aumento das doses de nitrogênio. A adubação nitrogenada proporcionou resposta quadrática com ponto de máximo sobre a taxa de transpiração foliar. A adubação nitrogenada favorece as trocas gasosas em capim-massai até a última dose estudada.

The aim of this study was to assess the effect of soil management and planting spacing on establishment performance of mixed swards of purple stargrass (Cynodon nlemfuensis cv. BRS Lua) and forage peanut (Arachis pintoi cv. Belmonte). The treatments comprised two methods of soil management (conventional tillage, with desiccation followed by harrowing; and no-tillage, with sequential desiccation with glyphosate) and two planting spacing (50 and 100 cm between rows). The experimental design was in randomized blocks, arranged in split-plot. Both methods of soil management ensured rapid pasture establishment, with canopy cover greater than 94 % at 84 d after planting, with the no-tillage surpassing the conventional tillage, and at a cost of no-tillage 7 % lower. Reducing planting spacing from 100 cm to 50 cm accelerated canopy cover and reduced weed incidence. The initial contribution of forage peanut in the botanical composition was relatively small, declining by 3.8 % on average at 36 d after planting to less than 1.2 % at 84 d. No-tillage was as efficient in establishing mixed swards as conventional tillage. Made available in DSpace on 2020-02-28T18:10:32Z (GMT). No. of bitstreams: 1 26980.pdf: 450963 bytes, checksum: 94144b8a51b55e0bf30351175f6a0d9a (MD5) Previous issue date: 2020

SOWING DENSITY, ESTABLISHMENT AND DRY MATTER PRODUCTION OF CEVADILHA VACARIANA. ABSTRACT: Bromus auleticus Trinius or cevadilha vacariana, is a perennial hibernal species native to the fields of southern Brazil, Uruguay and Argentina. The slow establishment is one of the problems pointed out in most works as the main difficulty for its use as perennial winter pasture. The present work aimed to study the effect of sowing density on the establishment and production of dry matter in B. auleticus, in the first and second year of pasture production. The applied treatments were sowing densities of 570 (T1), 840 (T2), 1,100 (T3), 1,350 (T4) and 1,700 (T5) viable seeds.m-2. There was no significant difference between treatments for the number of seedlings up to 35 days, nor for plant height up to 100 days after sowing and also for the number of days between sowing and first cut. Dry matter production was not affected by treatments either. In this experiment the sowing density had no influence on any of the evaluated characteristics. It was also not possible to establish an association between number of plants and dry matter production in the first cut in the year of establishment. Keywords: Bromus auleticus; Native forage; Temperate grass; Seeds Made available in DSpace on 2021-01-23T09:10:48Z (GMT). No. of bitstreams: 1 Artigo-RCR-Joao-Carlos.pdf: 505414 bytes, checksum: c88239461bb8c48757dd6dff3dda524d (MD5) Previous issue date: 2020

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.

This study aimed to assess the performance of intact and castrated beef cattle on the pasture of Brachiaria humidicola alone and intercropped with Arachis pintoi cv. BRS Mandobi. The experiment was carried out from February to June 2016 on the private property of a partner of Embrapa Acre. The experimental design was completely randomized in a 2×2 factorial arrangement, with two sex classes (intact and castrated) and two types of pasture (alone and intercropped). The leaf to stem ratio was high (P0.05) to intact animals. O objetivo deste trabalho foi avaliar o desempenho de bovinos de corte castrados e não castrados em pasto exclusivo de Brachiaria humidicola e consorciado Arachis pintoi cv. BRS Mandobi. O experimento foi conduzido em propriedade particular de produtor parceiro da Embrapa Acre, de fevereiro a junho de 2016. O delineamento experimental foi inteiramente casualizado, em arranjo fatorial 2x2, sendo duas classes sexuais (castrados e não-castrados) e dois tipos de pasto (exclusivo e consorciado). A relação folha/caule foi superior (P0,05) a animais não castrados. Made available in DSpace on 2020-12-16T09:04:16Z (GMT). No. of bitstreams: 1 27081.pdf: 1242609 bytes, checksum: ab64e138a6fd3ee2a61f91886317d2ef (MD5) Previous issue date: 2020

The breeding program of Urochloa ruziziensis evaluates many genotypes in initial phases. Evaluations through grades might make the selection less costly. The aim of this study was to verify the efficiency of visual selection for green biomass yield in relation to different selection strategies, such as mass selection by phenotypic mean, BLUP (Best Linear Unbiased Prediction) and at random. For this purpose, 2,309 regular genotypes were evaluated in an augmented block design in two cuts. The evaluators gave grades for plant vigor, and later, the plots were measured for green biomass yield. The coincidences of the selected genotypes were estimated by different selection strategies. Then, 254 clones of the genotypes selected in different strategies were evaluated in a clonal test in a triple lattice design in four cuts. The statistical analyses were performed in SAS using the Mixed procedure. The regular genotype level and clone-mean basis heritabilities were 31.16 and 62.91%, respectively, for green mass yield. The expected selection gains were 21.09% (visual), 25.43% (phenotypic mean), and 27.5% (BLUP). Moreover, the realized heritabilities for these strategies were 15.58, 11.87, and 15.86%, respectively, which might be associated with genotype by environment interaction. Therefore, the visual selection could be a useful strategy in initial phases of a U. ruziziensis breeding program because the efficiency was moderate to high in relation to phenotypic mean and BLUP. Made available in DSpace on 2021-08-18T19:00:36Z (GMT). No. of bitstreams: 1 Visual-selection.pdf: 509733 bytes, checksum: c82be484c697d4dcb07c3b8e2dfe31b5 (MD5) Previous issue date: 2020

The SPAD-502 (Soil Plant Analysis Development) chlorophyll meter is a simple diagnostic tool that instantly measures the chlorophyll content of plant leaves without damaging the leaf blade. This study aimed to evaluate the efficacy of the SPAD index as a tool for discriminating elephant grass acessions from different morphological groups. One hundred genotypes of the elephant grass Pennisetum purpureum from the Active Germplasm Bank at Embrapa Dairy Cattle, Minas Gerais, Brazil were evaluated. Following uniform cutting, six SPAD readings were taken from each accession every 60 days. Measurements were taken for two years. The experimental design was a 10 × 10 simple lattice with two replications. Joint deviance analysis for six SPAD measurements revealed great genetic variability between genotypes. SPAD values of Cameroon and Napier accessions were, on average, significantly different. The SPAD index was effective in detecting genetic variability between elephant grass acessions. However, it should not be used alone as a morphological descriptor, but in combination with other descriptors. Made available in DSpace on 2021-08-18T18:00:22Z (GMT). No. of bitstreams: 1 Use-SPAD.pdf: 243409 bytes, checksum: 40251aac2c5a2efb7d2590e73f1e7009 (MD5) Previous issue date: 2020 Short communication.

Made available in DSpace on 2020-06-19T04:11:51Z (GMT). No. of bitstreams: 1 Marcelo-Ayres-low-cytomolecular.pdf: 2539728 bytes, checksum: 9435c8b829edb6b876ae70c3157e189a (MD5) Previous issue date: 2020

The quality of seeds of forage species can be influenced by the different harvesting methods used. The aim of this study was to evaluate the physical and physiological quality of seeds of Panicum maximum, cultivars ‘Massai’ and ‘Mombaça’, obtained by the methods of ground sweeping and direct heading (cutting of the panicles) of different farmers in the year 2014. The test consisted of three lots of each cultivar from seed farmers in the state of Goiás, Brazil. The experimental design was completely randomized, in 3 x 2 factorial scheme (farmer x harvesting methods) with four replicates. The following variables were analyzed: physical purity, 1000-seed weight; germination and first count of germination. At the end of the germination the percentage of dormancy and dead seeds were evaluated by the tetrazolium test of the remaining seeds, in addition to the abnormal seedlings. The data were submitted to analysis of variance and the means of the treatments were compared by Tukey test at 0.05 probability level. Seeds of P. maximum ‘Massai’ and ‘Mombaça’ collected by ground sweeping have superior physiological quality despite the low level of purity of the lots, compared to direct heading method. RESUMO A qualidade de sementes de espécies forrageiras pode ser influenciada pelos diferentes métodos de colheita utilizados. Nesta pesquisa objetivou-se avaliar a qualidade física e fisiológica de sementes de Panicum maximum cultivares Massai e Mombaça, obtidas pelos métodos de colheita no cacho (corte das panículas) e varredura do solo, de diferentes produtores no ano de 2014. O ensaio constituiu-se de três lotes de cada cultivar oriundas de produtores de sementes do Estado de Goiás, Brasil. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 3 x 2 (produtor x método de colheita) com quatro repetições. Foram avaliadas: pureza física, massa de mil sementes; germinação e primeira contagem de germinação. Ao final do teste foram avaliadas as porcentagens de sementes dormentes e mortas, pelo teste de tetrazólio das sementes remanescentes, além das plântulas anormais. Após a obtenção dos dados, os mesmos foram submetidos à análise de variância e as médias dos tratamentos foram comparadas pelo teste de Tukey, a 0,05 de probabilidade. As sementes de P. maximum cultivares Massai e Mombaça colhidas por varredura do solo tem melhor qualidade fisiológica, apesar do baixo nível de pureza dos lotes quando comparadas à colheita no cacho.