Eficiência de utilização de nutrientes por cultivares de batata

The use of cultivars efficient in nutrient use is essential to increase yield and reduce production costs. The objective of this study was to evaluate absorption and nutrients use efficiency on five potato cultivars. The experiment was conduced in Itaí, São Paulo State, Brazil, in winter cropping season of 2008 on Oxisol. The experimental design was randomized blocks with split-plots and four replications. Plots comprised the five potato cultivars and subplots were established by sampling times, performed at planting and every seven days after emergence. At 97 DAP was calculated the nutrients use efficiency for dry matter production and at 122 DAP were calculated the nutrients use efficiency for fresh tuber and tuber dry matter yield. Mondial and Asterix cultivars showed greater dry matter production, higher fresh tubers yield and nutrients accumulation. Nutrients use efficiency for total dry matter and tubers dry matter, was similar among cultivars, but Ágata was more efficient in nutrients use efficiency for fresh tubers yield.

Acúmulo de biomassa em variedades de cana-de-açúcar inoculadas com diferentes estirpes de bactérias diazotróficas

The objective of this study was to evaluate the contribution of inoculation with diazotrophs, applied both individually and in combination, in commercial varieties of sugarcane. The experiment was carried out at the experimental grounds of Embrapa Agrobiologia, in Seropédica, Rio de Janeiro, Brazil. The experimental design was of randomised blocks, with sub-divided plots and six replications. Six varieties of sugarcane with six treatments were used: control, control with nitrogen, inoculation of the individual strains: BR 11512, BR 11724 and BR 11411, in addition to inoculation with a cocktail consisting of five strains of diazotrophs. Differences were observed between varieties and between treatments, and an interaction observed between the treatments and varieties. For all the parameters evaluated, no response was observed in the sugarcane varieties RB855536 and RB92606. In the variety RB918639, the only difference was in the accumulation of green biomass. No difference was observed between the treatments for total nitrogen accumulation. The most responsive variety to inoculation was RB867515, differing in the accumulation of fresh and dry biomass. This study showed that inoculation promotes the accumulation of biomass, the contribution being different for the varieties and strains of bacteria, suggesting an interaction between the factors studied. The variety RB867515 is promising for use in studies of inoculation with diazotrophs.

Consumo, digestibilidade aparente de nutrientes e balanços de nitrogênio e hídrico de ovinos alimentados com silagens de cultivares de capim-búfel

The objective of this present experiment was to determine intake and apparent digestibility of dry matter and nutrients, nitrogen (NB) and water balances (WB) of sheep fed with buffel grass silages. The buffel grass cultivars used were Tanzania, Buchuma and Biloela. 21 male, castrated, crossbred Santa Ines x Non defined genotype sheep, with initial body weight of 31.8±3.16kg were used, kept in metabolic cages. The experimental design was completely randomized with seven replicates. No differences were observed in dry matter intake in g/day (919.2) and % of body weight (2.9). In general, digestibility coefficients of dry matter varied from 37.7% to 60.0%. The NB and WB were positive, with higher NB values in sheep fed with Tanzania (5.1g/day) and Biloela (3.9g/day) and higher WB in animals fed with Buchuma (1.38kg/animal/day) and Biloela (1.42kg/animal/day). All cultivars of buffel grass evaluated (Tanzania, Buchuma and Biloela) presented adequate chemical composition, where the silage of buffel grass used corresponded to 60% of the total daily water intake by sheep.

Consumo e digestibilidade aparente dos nutrientes em ovinos alimentados com dietas contendo diferentes quantidades de farelo de linhaça

The aim of this research was to evaluate the intake and apparent digestibility of nutrients in sheep fed with diets containing different amounts of linseed meal. The treatments evaluated were: corn silage exclusive (control); corn silage + concentrate; corn silage + concentrate + 5% of linseed meal; corn silage + concentrate + 10% of linseed meal. The dry matter (DM) intake has increased in diets containing concentrated if compared to diet exclusively with corn silage (P<0.05), however, there was no effect of the inclusion of linseed meal in diets (0; 5 and 10%). As it was expected, the diets containing 5 and 10% of linseed meal resulted in an increase of ether extract (EE) intake. A higher apparent digestibility of DM, organic matter (OM) and neutral detergent fiber (NDF) in the animals fed with diets containing the concentrate was observed, independently of linseed meal proportion. According to the experimental conditions under which the experiment was developed, itis recommended to provide the diets containing until 5% of linseed meal, because there is no negative effect on dry matter and nutrients intake, as well as on apparent digestibility.

Acúmulo de nutrientes no colmo de cana-de-açúcar em função de fontes e doses de manganês

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Acúmulo e exportação de nutrientes em cenoura 'Forto'

In order to quantify the growth, accumulation and exportation of macronutrients by carrot 'Forto', and obtain equations that best represent them, it was conducted an experiment in the São Gotardo (MG), from May to September 2004. Samples were taken at 40, 50, 60, 70, 80, 90, 100, 110 and 120 days after sowing (DAS) to determine dry matter and accumulation of macronutrients in leaves and roots. At 40 DAS, five days after thinning, the plants had 0.18 g and 0.04 g in dry leaves (LDM) and of roots (RDM), respectively. From then, until 88 DAS, the partitioning of photoassimilates and accumulation of matter in the shoots were more pronounced. The RDM was low until 80 DAS, which corresponded to two thirds of the crop cycle, from when the amount of material allocated in this part of the plant had strong growth, surpassing, at 88 DAS, the amount of LDM. The nutrient accumulation was small in the first 60 DAS, coinciding with the period of lower dry matter accumulation. The order of decreasing macronutrient accumulation by the crop were: K > N > Ca > P > S > Mg, in the amounts of 906.7, 438, 155.46, 87.4, 58 and 37.63 mg plant-1, respectively. The root participated with 60.5% of the accumulation of N, 86.1% of P, 58% of K, 25.5% of Ca, 55.6% of Mg and 65.5% of S. Considering a population of 590,000 plants per hectare, the total quantity of nutrients by the crop of carrots was 258.3, 51.6, 534.8, 91.7, 22.2 and 34.2 kg N ha-1, P, K, Ca, Mg and S, respectively.

Produção e teores de nutrientes no capim braquiária adubado com nitrogênio e enxofre

Among the production factors, adequate fertilization is an important tool to raise the productivity of pastoral systems and consequently increase the share of Brazil in the supply chain of primary agricultural products at the global level. The objective of this study was to evaluate the interaction of nitrogen and sulfur fertilization in Brachiaria decumbens Stapf. The experiment in pots with Dystrophic Oxisol was evaluated in a completely randomized design with four replications in a 5 x 3 factorial arrangement, involving five N doses (0, 100, 200, 400, and 800 mg dm-3) in the form of ammonium nitrate and three S doses (0, 20 and 80 mg dm-3) in the form of calcium sulfate, with a total of 15 treatments. In the treatments with low S dose, calcium was provided as calcium chloride, to ensure a homogeneous Ca supply in all treatments. The results showed that the tiller production and dry weight of green leaves and of stems + sheaths and total dry weight were favored by the combination of N and S fertilizer, while the proportion of dry leaves was reduced. Nitrogen fertilization raised the N contents in green leaves and stems + sheaths and reduced K contents in fresh and dry leaves. The response to S rates in the N content of green leaves was quadratic.

Extração e exportação de nutrientes em cultivares de feijoeiro, sob níveis de adubação: I - Macronutrientes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Extração e exportação de nutrientes em cultivares de feijoeiro, sob níveis de adubação: II - Micronutrientes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito da inulina e de probióticos sobre a digestibilidade dos nutrientes e balanço do nitrogênio em leitões

This study aimed to evaluate different inulin and probiotic levels as supplement in diets for piglets on nutrient digestibility and nitrogen balance. Twenty four crossbred barrows (Pietráin × Landrace × Large White), with initial average weight of 18.00 ± 0.38 kg, were individually housed in metabolic cages. The experimental design was a completely randomized block, in a 2 × 3 factorial scheme (probiotic levels: 0.30 and 0.60 %; inulin levels: 0.00, 0.25 and 0.50 %), with four replications. The probiotic used was a mix of Lactobacillus acidophillus, Streptococcus faecium and Bifidobacterium bifidum. The inulin was the prebiotic used in this study, characterized as an indigestible carbohydrate formed by fructooligosaccharides. Inulin levels provided a quadratic effect (p<0.05) on the digestibility coefficients of dry matter, organic matter and ether extract, and the better responses were obtained supplementing 0.194, 0.185 and 0.188 %. Quadratic effects were observed for the nitrogen excreted in feces, total nitrogen excretion, nitrogen efficiency use and nitrogen digestibility. The inulin levels of 0.194 and 0.216 %, in piglet diets, were the better for dry matter digestibility and total nitrogen excretion, respectively.

Efeito residual de fontes de fósforo nos atributos químicos do solo, nutrição e produtividade de biomassa da cana-de-açúcar

In tropical regions, the residual effect of phosphate fertilizer source is of crucial importance. This study aimed to evaluate the effects of application of P sources in chemical properties of soil, nutrition and productivity of sugarcane plant and during the first and second ratoon. The sources of P applied in furrows at planting were, triple superphosphate, Arad phosphate, bone meal (100 kg ha-1 P2O5 total) and a control without P, the varieties of sugarcane studied were IAC86-2480 and SP79-1011. A randomized block design in a 4 × 2 factorial was used, with four replications. The study was conducted in the municipality of Alta Floresta-MT, Brazil, in Typic Hapludox. After each cutting, in soil P content, pH and Ca were evaluated. In the plant, the production of green and dry matter of shoots, the concentration of P in the biomass harvested, the export of P and agronomic efficiency of the sources of P were determined. The bone meal had a higher agronomic efficiency resulted in greater accumulation and export of P by crop, higher content of available Ca and P and increase soil pH. The Arad reactive phosphate increased its agronomic efficiency between crop cycles.

Crescimento, produtividade, acúmulo e exportação de nutrientes em cultivares de batata (Solanum tuberosum L.)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Crescimento, alocação de recursos e requerimento de nutrientes em Heteranthera reniformis Ruiz e Pav

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Métodos híbridos de pontos interiores e de programação inteira 0-1 para problemas de custo de colheita da cana-de-açúcar e de custo de coleta e geração de energia relacionados à sua biomassa

Pós-graduação em Engenharia Elétrica - FEB

Efeitos dos poluentes gerados pela queima de biomassa no transporte mucociliar nasal e percepção da qualidade de vida de cortadores de cana

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)