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The objective of this work was to evaluate crops for their ability to phytoremediate diclosulam residues in the soil and produce lignocellulosic ethanol. Physiological characteristics, biomass production, soil cover rate, fermentable sugar production and lignocellulosic ethanol production potential of the crops were evaluated in soil with diclosulam residues. The experimental design was a randomized block with four replications. The treatments were arranged in a 4 × 2 factorial scheme with the following crops as the first factor:Phytoremediation of soils with herbicide residues is a viable tool and has been increasingly widespread throughout the world. The use of plant species capable of making the soil feasible for successive plantings sensitive to previously applied residual herbicides is a way to optimize agricultural production. However, there are few studies in which vegetable biomass used in the phytoremediation process is used. Thus, our study is innovative because it seeks to combine phytoremediation with the production of bioethanol, ensuring even more sustainable agriculture.

The goal of this study was to evaluate the morphogenetic, physiology, and forage mass characteristics of Mavuno brachiariagrass (Urochloa brizantha × Urochloa ruziziensis) under shading. The experiment was analyzed as split-plot. Whole plots were two growing seasons (spring/summer and fall/winter) and the subplots were shade levels (0, 30, 45, and 73%). There is a linear positive effect of shade on leaf elongation rate, leaf blade lengths, canopy height, chlorophyll indices, leaf percentage, and leaf to stem ratio. Shade linearly decreased stem and inflorescence percentages and tillers number. There was a quadratic effect of shade on growing cycle length, forage mass, and photosynthesis. Regarding to seasons, spring/summer presented higher rates of leaf appearance, leaf elongation, and stem elongation compared to fall/winter. In conclusion, Mavuno brachiariagrass harvested at 95% LI presents great adaptation to shading of 30%, without impairing the forage mass although increasing leaf size, chlorophyll indices, and canopy height.

The objective of this study was to evaluate the effects of different crop arrangements and weed management in integrated crop–forage–forestry systems on weed incidence, yield of maize and forage grass, quality of total harvested and tree development. The experiment was analyzed as split-plot and as randomized complete block design. Whole plots were crop arrangements containing maize, Marandu palisadegrass, Basilisk signalgrass, Piata palisadegrass, eucalyptus and acacia, and subplots were the weed management (1.5 kg ha−1 of atrazine and 1.5 kg ha−1 of atrazine + 0.006 kg ha−1 of nicosulfuron). Planting was done under no-tillage system and herbicides were applied 22 days after maize emergence. The weeds incidence was not affected by treatments. Applying the mixture of atrazine and nicosulfuron reduced the grasses yield. However, the total dry mass harvested was not affected. The average yield of whole-plant corn in the intercropping systems was 12.9 t ha−1 of dry mass. The simultaneous establishment of the integrated crop–forage–forestry systems does not reduce the productivity and quality of whole-plant corn nor the production of the tree component at the first cultivation year. Despite the reduced grasses yield, the application of nicosulfuron and atrazine does not improve the production and quality of whole-plant corn in relation to the application of atrazine alone.

The objective of this work was to evaluate the morphogenetic, structural, physiological, and productive traits of forage peanut (Arachis pintoi) subjected to different levels of artificial shading in the field. The 'Amarillo MG-100' forage peanut was planted in April 2015, and the evaluations were carried out from May 2017 to April 2018. The treatments were: 0, 30, 45, and 75% of artificial shading. There was no significant effect of shading on the morphogenetic traits of forage peanut. Shading increased final leaf length and canopy height and decreased the leaf area index and number of stolons. Photosynthesis, transpiration rate, stomatal conductance, chlorophyll b, and leaf temperature increased quadratically as a function of shading. There was a linear positive effect on the growing cycle length and a quadratic effect on the production of dry matter mass, with the maximum at 30% shade. Forage peanut harvested at 95% light interception (11-cm height) shows adaptation to shading up to 45%, with increased leaf size, canopy height, photosynthetic rate, stomatal conductance, transpiration rate, and chlorophyll b. In addition, plants at 30% shading show a higher yield than those growing under full sun. Resumo: O objetivo deste trabalho foi avaliar as características morfogenéticas, estruturais, fisiológicas e produtivas do amendoim-forrageiro submetido a diferentes níveis de sombreamento artificial no campo. O amendoim-forrageiro 'Amarillo MG-100' foi plantado em abril de 2015, e as avaliações foram realizadas de maio de 2017 a abril de 2018. Os tratamentos foram: 0, 30, 45 e 75% de sombreamento artificial. Não houve efeito significativo do sombreamento sobre as características morfogenéticas do amendoim-forrageiro. O sombreamento aumentou o comprimento final da folha e a altura do dossel e diminuiu o índice de área foliar e o número de estolões. A fotossíntese, a taxa de transpiração, a condutância estomática, a clorofila b e a temperatura das folhas aumentaram quadraticamente em função do sombreamento. Houve efeito linear positivo sobre o tamanho do ciclo de crescimento e efeito quadrático sobre a produção de massa de matéria seca, com o máximo a 30% de sombra. O amendoim-forrageiro colhido a 95% de interceptação luminosa (11 cm de altura) apresenta adaptação ao sombreamento de até 45%, com aumento do tamanho das folhas, da altura do dossel, da taxa fotossintética, da condutância estomática, da taxa de transpiração e da clorofila b. Além disso, as plantas sob sombreamento de 30% apresentam maior rendimento do que aquelas que crescem sob a luz do sol.

CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Outra Agência The aim of this work was to study the effect of sub-doses of herbicide nicosulfuron on the levels of chlorophyll and growth of marandu-grass in an forest-livestock integration system. The treatments consisted of eucalyptus consortium with sorghum (BRS 655 hybrid) and forage Urochloa brizantha cv. Marandu (marandu-grass) at 12×2 and 12×3 m spacings in agroforestry systems, in addition to sorghum + marandu-grass and marandu-grass in monoculture. The doses of nicosulfuron applied at the marandu-grass were 0, 15 and 30 g ha-1. At 30 and 120 days after the application of nicosulfuron, chlorophyll a and chlorophyll b were measured usinf a portable chlorophyll meter, with six measurements per plant. Afterwards, the total chlorophyll content and chlorophyll a/b were calculated. We also measured the mass of the total dry matter of marandu-grass and growth rate of the culture. Marandu-grass plants cultivated in monoculture showed higher quantities of chlorophyll and the highest growth rates. The levels of chlorophyll a, b and chlorophyll a/b and the growth rate of marandu grass were similar between systems integrated with eucalyptus (12x2 and 12x3 m). The increase of herbicide dose negatively influenced on chlorophyll content in marandu-grass in all treatments evaluated. The use of nicosulfuron in doses of 25 and 50 g L-1 reduced the growth rate of marandu grass only when grown in monoculture.

Tithonia diversifolia (Tithonia) is performed as an invasive species with a high adaptive potential that can be used for several purposes, including an alternative source of forage for different animal categories. The use of Tithonia is growing rapidly as farmers recognize its high accumulation of biomass, good nutritional value and adaptation to tropical environments. However, the effects of irrigation and nitrogen on the characteristics of Tithonia have been poorly studied. In this context, the objective of this study was to identify changes in the productive characteristics and morphophysiology of Tithonia under different irrigation simulations and nitrogen fertilization rates, seeking to understand its adaptive potential in different water and nutritional scenarios, improvements in the efficiency of the use of water and nitrogen and its potential for use in a global context. Field trials was a split-plot design with three replicates. Whole plots were irrigation rate (0%, 25%, 50%, 75% and 100% of crop evapotranspiration - ETc) and the subplots were the nitrogen fertilizer rate (0, 50, 100 and 150 kg ha−1). There were significant effects of irrigation, nitrogen, and their interaction on dry biomass accumulation, nitrogen- and water-use efficiency, plant height, chlorophyll index, and photosynthetic rate. Irrigation and nitrogen rates increased the dry biomass accumulation. The highest dry biomass accumulation was 7.32 Mg ha−1 in cycle I and 10.4 Mg ha−1 in cycle II. The greatest nitrogen-use efficiency was observed at a rate of 100 kg of nitrogen ha−1, and the greatest water-use efficiency was observed at irrigation 75% ETc. Irrigation and nitrogen also increased plant height, chlorophyll index, and photosynthetic rate. Tithonia proved to be a plant adapted to the humid temperate climate and sandy-loam texture soil, presenting great dry biomass accumulation potential even without irrigation and nitrogen fertilization. However, the greatest dry biomass accumulation was obtained with water replacement of 100% of ETc, the crop evapotranspiration, and nitrogen fertilization of 150 kg ha−1.

The objective was to evaluate the productive and economic performances of 32 Nellore bulls kept in a feedlot provided with different levels of sugarcane tops as a substitute for sugarcane, in diets containing 33% of roughage. Four levels of substitution were evaluated: T0 = no addition of sugarcane tops; T33 = 33% substitution; T67 = 67% substitution; and T100 = total substitution of sugarcane by sugarcane tops. Shrunk body weight was measured at the beginning and end of the experiment. Dry matter, crude protein (CP), neutral detergent fiber (NDF), ether extract (EE) and non-fibrous carbohydrate (NFC) intakes, total body weight gain, average daily gain, and feed conversion ratio were evaluated. In addition, economic parameters (total revenue, effective operating cost, total operating cost, gross margin, and net margin) were assessed, and indexes previously reported in the literature were utilized in the determination of feedlot costs. The CP, NDF, EE, and NFC intakes were different (P 0.38) among treatments. All treatments presented a positive net margin, which represents that the utilization of any level of sugarcane tops is viable. However, the 33% substitution provided the greatest numerical net margin value. In conclusion, partial or total substitution of sugarcane by sugarcane tops in diets containing 33% of roughage does not affect the performance of feedlot young bulls; moreover, it is recommended to substitute sugarcane by sugarcane tops at 33% since, at this level, a numerical reduction of production costs and greater numerical gross and net margins are obtained when compared with other levels of substitution.

Integrated systems have been gaining prominence in recent years, especially the crop-livestock-forestry, which, in addition to being an alternative income per area, increase fertility and organic matter content in the soil, and protect animals against weather conditions. However, there is still a lack of knowledge about the management of pastures under such conditions. Therefore, the aim of this research was to evaluate the grazing management and nitrogen fertilization in Marandu palisade grass consorted with Eucalyptus to obtain the greater of forage production. The experimental design was a randomized block, arranged in split-plot, the plots were composed of two eucalyptus spacing (12 x 2 or 12 x 3) and Marandu monoculture, the subplots were composed of the nitrogen fertilization rate (0, 100, 200 kg N/ha using ammonium sulfate). The higher DM accumulation rate was observed at 200 kg N ha-1 (69.29 kg DM ha-1 day), while there was no difference between the treatments without fertilization and 100 kg N ha-1 (P > 0.001). DM accumulation rate increased by 30.01% when fertilization increased from 100 kg N ha-1 to 200 kg N ha-1. Marandu palisade grass with 200 kg N ha-1 showed the highest production (28.82 t ha-1) independent of spacing. In the silvopastoral system, the greater accumulation of forage was observed when handled with 80% of the light interception (LI), corresponding to a height of 67 cm. Therefore, we conclude that Marandu grass in a silvopastoral system, without N fertilization, should be managed with a pre-grazing height of 60 cm and 73% LI. Marandu grass in a silvopastoral system, with 100 kg N ha-1 fertilization, should be managed with a height of 68 cm and 84% LI, and, with 200 kg N ha-1, should be managed at 80% of LI for the greater pasture utilization and development.

O benefício do silício (Si) no crescimento de plantas cultivadas tem sido observado em vários trabalhos. O objetivo deste estudo foi avaliar os efeitos de Si no crescimento de mudas de cafeeiro cv. Catuaí Vermelho. O experimento foi conduzido em vasos, e as plantas crescidas em casa de vegetação, sem restrição hídrica. A partição de matéria seca entre raízes, caule e folhas, os teores de nutrientes e Si nos tecidos vegetais e no solo e as trocas gasosas foliares foram avaliados em plantas submetidas a doses de silicato de cálcio correspondentes a 0 (controle), 1,5 e 6 Mg ha-1. O delineamento experimental foi em blocos casualizados, com três tratamentos e 3, 4 ou 18 repetições, dependendo da variável considerada. Cada parcela experimental era composta por uma planta. Em relação à altura e matéria seca total, as plantas de todos os tratamentos apresentaram desenvolvimento satisfatório, com incrementos diários compatíveis com o esperado em cafeeiros bem nutridos. Os tratamentos com silicato de cálcio causaram aumento nos teores de Ca no solo e na planta e de Si no solo. Considerando que o único nutriente alterado pelos tratamentos foi o Ca e que os teores observados na planta podem ser considerados não prejudiciais, as respostas descritas a seguir são consequência do alto teor de Si no solo. Após 130 dias do início do experimento, as plantas tratadas com 6 Mg ha-1 de silicato de cálcio apresentaram menor acúmulo de matéria seca nas raízes e aumento da relação entre a matéria seca da parte aérea e a do sistema radicular. Embora as plantas tenham apresentado menor crescimento radicular na maior dose de silicato de cálcio, a assimilação de CO2 e a condutância estomática não foram alteradas. Cafeeiros arábica cv. Catuaí Vermelho submetidos a alta dose de silicato de cálcio apresentam redução do crescimento radicular, porém sem comprometimento da funcionalidade e do desenvolvimento da parte aérea das plantas cultivadas sob boa disponibilidade hídrica e nutricional. Several studies have confirmed the benefits of silicon (Si) for crop growth. The purpose of this study was to evaluate the effects of Si on the initial growth of coffee plants cv. Catuaí Vermelho. This study was carried out with potted plants grown in a greenhouse, without water deficiency. Dry matter partitioning of roots, stems and leaves as well as the chemical composition of plant tissues and soil and leaf gas exchange were evaluated in plants treated with 0 (control), 1.5 and 6 Mg ha-1 of calcium silicate. The experiment was arranged in a randomized block design, with three treatments, and 3, 4 or 18 replications, depending on the evaluated variable. Each plot consisted of one plant. Regarding height and total dry matter, the plant growth was satisfactory in all treatments, with daily increases similar to the expected for well-fertilized coffee plants. The treatments resulted in increased soil and plant Ca and Si concentrations. Considering that only leaf Ca concentration was affected by treatments and its concentration was not deleterious, the observed responses are consequences of the high soil Si concentrations. Root dry matter of plants treated with 6 Mg ha-1 of calcium silicate decreased and the ratio between shoot and root dry matter increased 130 days after the beginning of the experiment. Despite the decreases in root growth and in Ca use efficiency, leaf CO2 assimilation and stomatal conductance of the coffee plants were not affected. In summary, high soil concentrations of calcium silicate decrease the root growth of Arabica coffee plants cv. Catuaí Vermelho; however, the functionality and development of shoots in well-nourished plants growing under well-watered conditions are not affected.

Phytomass production is a result of physiological processes occurring at plant canopy level, with canopy architecture affecting the availability of solar radiation to photosynthesizing tissues. The aim of this study was to identify a possible association between light availability, canopy photosynthesis and plant growth in three sugarcane varieties under field conditions. As a hypothesis, higher canopy photosynthesis and plant growth are probably found in sugarcane varieties with higher light availability at bottom canopy positions. Measurements of diurnal course of leaf gas exchange were taken in two canopy positions of the sugarcane varieties IACSP93-2060, IACSP95-3028 and IACSP95-5000, maintaining the natural leaf inclination. All sugarcane varieties exhibited similar values of diurnal CO2 uptake at the upper canopy position. On the other hand, the bottom canopy position had an important role on photosynthesis of IACSP95-3028 sugarcane, with slight changes in leaf inclination causing significant variation of photosynthetic active radiation at the bottom canopy positions. High light availability at the bottom canopy position of IACSP95-3028 caused increased photosynthesis and improved plant vegetative growth, given by increases in tillering, leaf area and leaf and stalk phytomass accumulation.

Objetivou-se avaliar as exigências nutricionais de proteína e energia de vacas nelores em lactação no período de 0 a 180 dias. Foram utilizadas 20 vacas primíparas com peso corporal médio ao parto de 362±25 kg. Quatro vacas foram abatidas logo após o parto e foram consideradas grupo referência. Do parto aos 90 dias, quatro vacas receberam alimentação restrita na proporção de 1,5% do peso corporal (PC), em porcentagem da matéria seca (MS), e 12 foram alimentadas à vontade. Aos 90 dias do pós-parto, foram abatidas oito vacas (quatro de cada oferta alimentar). Dos 90 aos 180 dias, quatro vacas foram realocadas para mantença (1,8% PC em MS) e quatro continuaram em consumo voluntário, sendo todas abatidas ao final do período. Os conteúdos corporais de proteína e energia foram estimados pelo equação Y = a . Xb, em que X é o peso de corpo vazio (PCVZ) e a e b os parâmetros da equação. Foram obtidas relações médias de 0,894 para PCVZ/PC e de 0,936 para ganho de PCVZ (GPCVZ)/ganho de PC (GPC). As exigências líquidas de energia para mantença (ELm) foram de 97,84 kcal/PCVZ0,75 e as de energia metabolizável para mantença (EMm), 140,17 kcal/PCVZ0,75. As eficiências de utilização da energia para mantença e ganho de peso foram 0,70 e 0,44, respectivamente. Os conteúdos corporais de proteína diminuíram com o aumento do PC, enquanto os de energia aumentaram. No leite das vacas, foram determinados teores médios de 3,71; 3,88; e 4,74%, respectivamente, de proteína bruta, gordura e lactose. A exigência de ELm para lactação de vacas nelores é de 97,84 kcal/PCVZ0,75, enquanto a de EMm é de 140,17 kcal/PCVZ0,75 e a de proteína metabolizável, de 52,8 g. Para produzir 1 kg de leite com 4% de gordura, vacas nelores necessitam de 0,300 kg de NDT. This study was conducted to evaluate the nutritional requirements of protein and energy of primiparous lactating Nellore cows from 0 to 180 days after calving. A total of 20 lactating primiparous cows with average body weight at calving of 362±25 kg were used. Four cows were slaughtered soon after calving and were considered as reference group. From calving to 90 days post partum four cows were fed restricted at 1.5% of body weight (BW) in dry matter (DM) basis and 12 were fed ad libitum. At 90 days post partum eight cows were slaughtered (four from each feeding system). From 90 to 180 days, four cows were realocated for maintenance (1.8% BW in DM) and four remained in voluntary intake, and all were slaughtered at the end of the period. The contents of protein and energy were estimated by the equation Y = a. Xb, in which X is the empty body weight (EBW), and a and b are the parameters of the allometric equation. Ratios obtained for empty body weight (EBW)/BW and empty body gain (EBWG)/BWG were 0.894 and 0.936, respectively. The net energy for maintenance (NEm) were 97.84 kcal/EBW0.75 and the metabolizable energy for maintenance (MEm) were 140.17 kcal/EBW0.75. The efficiencies of energy use for maintenance and gain were 0.70 and 0.44, respectively. The content of protein and minerals, except calcium, decreased with the increase in BW while the energy increased. The milk of cows had average contents of 3.71, 3.88 and 4.74%, respectively, for crude protein, fat and lactose. The NEm requirement for lactating Nellore cows is 97.84 kcal/EBW0,75, while MEm is 140.17 kcal/EBW0,75 and metabolizable protein requirement is 52.8 g. To produce 1 kg of milk with 4% fat Nellore cows need 0.300 kg TDN.

O objetivo deste trabalho foi avaliar de que maneira a alta disponibilidade de fósforo no solo afeta a fotossíntese e o crescimento de mudas de cafeeiro arábica (Coffea arabica). Mudas da cultivar Ouro Verde com aproximadamente quatro meses de idade, cultivadas com boa disponibilidade hídrica, foram submetidas a três tratamentos quanto à disponibilidade de fósforo: quantidade recomendada de P, na literatura (PA); duas vezes a dosagem utilizada em PA (P+); e sem adição de P ao solo (P-). Após 70 dias da aplicação dos tratamentos, foram avaliados: as trocas gasosas, a atividade fotoquímica, o potencial de água da folha, a condutância hidráulica da planta (K L), a partição de matéria seca na planta, os teores de pigmentos e carboidratos, e a composição química das folhas. O tratamento P- influenciou negativamente a fotossíntese, e levou à restrição do crescimento das plantas. As plantas do tratamento P+ apresentaram maior teor foliar de P (~1,9 g kg-1), com incrementos na assimilação de CO2, na eficiência instantânea de carboxilação e na atividade fotoquímica - maior eficiência do fotossistema II e maior transporte aparente de elétrons - em relação às plantas do tratamento PA. Houve aumento em K L, maior teor de carboidratos foliares e maior teor de clorofila nas plantas que receberam o dobro da dose recomendada de P, as quais apresentaram maior produção de matéria seca em relação às de PA e P-. The objective of this work was to evaluate how high soil phosphorus (P) availability affects the photosynthesis and growth of young coffee arabica plants (Coffea arabica). Four months old coffee seedlings of the Ouro Verde cultivar, cultivated in good hydric conditions, were exposed to three P availability treatments: P dosage recommended in the literature (RP); two times the recommended dosage (P+); and without P (P-). Seventy days after treatment application, evaluations of leaf gas exchange, photochemical activity, leaf water potential, plant hydraulic conductance (K L), dry matter partitioning, leaf contents of pigments and carbohydrates, and leaf chemical composition were done. The treatment without P caused reduction in photosynthesis, leading to lower plant growth. The plants of the P+ treatment showed the highest leaf P concentrations (~1.9 g kg-1), with increasing leaf CO2 assimilation and instantaneous carboxylation efficiency, and higher photochemical activity - higher effective quantum efficiency of photosystem II and apparent electron transport rate - when compared to plants exposed to RP treatment. Plants exposed to the double P recommended dosage exhibited higher K L, higher leaf carbohydrate content and higher chlorophyll content, resulting in higher dry matter production as compared to RP and P-.