339 resultados para axillary shoots
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The modern tomato production, either for fruit table production or for processing, has required quality seedlings, able to withstand environmental adversities after planting and maintaining the standard genotype productive. The aim of this study was to evaluate the effect of three concentrations of PBZ (0, 50 and 100 mg L-1) and two methods of application (seed treatment and watering seedlings) on seedling emergence and seedling production of tomato growth indeterminate. We adopted a completely randomized in a 2x3 factorial scheme with four replications. We evaluated the seedling emergence, the rate of speed of emergence, seedling height and diameter of hypocotyl and their absolute growth rate (TCA), leaf area, dry weight of shoots, roots and total, and reason leaf area (RAF). Results were subjected to analysis of variance and the mean levels of the factor methods of application compared by Tukey test at 5% and the mean levels of the factor concentrations subjected to regression analysis. The application of paclobutrazol via seedlings watering did not affect seedling emergence, significantly reduced the rate of seedling growth and, consequently, the size of the seedlings without affecting the diameter of hypocotyl, plus allow accumulation of dry roots. A concentration of 50 mg L-1 was shown to be sufficient to obtain seedlings more compact, subject to leaf area, the application via watering, beyond allowing an increase of about 37% in dry weight of roots.
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The aim of this study was to assess the risk of metabolic syndrome (MetS) in postmenopausal breast cancer survivors as compared with postmenopausal women without breast cancer. METHODS: In this cross-sectional study, 104 postmenopausal breast cancer survivors were compared with 208 postmenopausal women (controls) attending a university hospital. Eligibility criteria included the following: amenorrhea longer than 12 months and aged 45 years or older, treated for breast cancer, and metastasis-free for at least 5 years. The control group consisted of women with amenorrhea longer than 12 months and aged 45 years or older and without breast cancer, matched by age and menopause status (in a proportion of 1:2 as sample calculation). Clinical and anthropometric data were collected. Biochemical parameters, including total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, glucose, and C-reactive protein, were measured. Women showing three or more diagnostic criteria were diagnosed as having MetS: waist circumference of 88 cm or larger, blood pressure of 130/85 mm Hg or higher, triglycerides level of 150 mg/dL or higher, high-density lipoprotein cholesterol level lower than 50 mg/dL, and glucose level of 100 mg/dL or higher. For statistical analysis, Student's t test, χ2 test, and logistic regression (odds ratio [OR]) were used. RESULTS: The mean (SD) age of breast cancer survivors was 60.6 (8.6) years, with a mean (SD) follow-up of 9.4 (4.4) years. A higher percentage of breast cancer survivors (46.2%) were obese as compared with controls (32.7%; P < 0.05), and a smaller percentage showed optimal values for low-density lipoprotein cholesterol, glucose, and C-reactive protein versus controls (P < 0.05). MetS was diagnosed in 50% of breast cancer survivors and in 37.5% of control group women (P < 0.05). Among the MetS diagnostic criteria, the most prevalent was abdominal obesity (waist circumference >88 cm), affecting 62.5% and 67.8% of the participants, respectively. In the control group, breast cancer survivors had a higher risk for MetS (OR, 1.66; 95% CI, 1.04-2.68), dysglycemia (OR, 1.05; 95% CI, 1.09-3.03), and hypertension (OR, 1.71; 95% CI, 1.02-2.89). CONCLUSIONS: Postmenopausal breast cancer survivors present a higher risk of developing MetS as compared with women without breast cancer. © 2012 by The North American Menopause Society.
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This work aimed to evaluate the effects of liming and phosphate fertilizer for the production of sabiá (Mimosa caesalpiniifolia Benth.) seedlings without thorns under a greenhouse. Seedlings 10 days old were transferred to plastic bags containing 2.0 kg of psamitic Dystrophic Red-Yellow Latosol (Typic Haplustox) collected from 40 to 70 cm layer. The experiment was carried out in Teresina county, Piauí state, Brazil, from July to October of 2008. Two liming doses (with and without liming) and five phosphorus doses combined in a 2 x 5 factorial scheme were used. The experimental design used was the randomized blocks with four replications having each plot three seedlings. The calculated lime amount was enough to elevate the base saturation to 50 % and the phosphorus doses were: 0, 30, 60, 90, and 120 mg kg-1 of soil. One seedling per pot was cultivated and the pot dimension was 10 by 23 cm. The evaluated variables were height, diameter, leaves number, leaf area, and shoot and roots dry matter. For the studied soil condition, the liming is not necessary to produce 'Sabiá' seedlings. The application, on average, from 72 to 107 mg kg-1 of P promote, respectively, from 90 to100 % of maximum values of height, diameter, leaf area and shoots and roots biomass.
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The use of biofertilizers is interesting for agriculture as being an economical alternative as well as it is environmentally friendly by using organic waste and reducing the application of mineral fertilizers. The aim of this study was to evaluate the effect of biofertilizer doses of bovine origin (biodigester effluent) applied on the ground and two levels of irrigation on lettuce. The experiment was conducted under protection of a greenhouse in pots, applying to the soil different doses of biofertilizer of bovine origin obtained from anaerobic reactor (10, 20, 40 and 60 m3 ha-1) and mineral fertilizer as a witness in two irrigation levels calculated at 50 and 100% of reference evapotranspiration. The lettuce plants were analyzed in their: Height, leaves number, crown diameter, fresh weight and dry weight of shoots. The biofertilizer treatments showed better results than the mineral fertilizer and has increased with increasing doses of biofertilizer, the highest dose (60 m3 ha-1) showed the best results in all variables. For dry, mineral fertilization showed higher values. The irrigation levels had no effect on plant growth.
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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.
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An efficient cryopreservation protocol was developed for mature seeds of Oncidium flexuosum Sims. Seed morphology, protocorm formation, and early seedling development were also assessed. The effects of phloroglucinol and Supercool X-1000® as cryoprotectant additives in the vitrification solution were investigated. Dehydration using the plant vitrification solution 2 (PVS2) for 60 and 120 min prior to immersion in liquid nitrogen promoted the highest frequency of in vitro seed germination 6 weeks following culture on half-strength Murashige and Skoog (1/2 MS) medium. Mature seeds submitted to vitrification for 120 min in PVS2 and 1 % phloroglucinol at 0 °C enhanced germination by 68 %, whereas in PVS2 and 1 % Supercool X-1000® germination was just moderately enhanced (26 %). In vitro-germinating seedlings developed healthy shoots and roots without the use of plant growth regulators. After 6 months of growth, there were no differences between in vitro- and ex vitro-grown seedlings for various phenotypic characteristics, including shoot length, number of leaves, number and length of roots, and fresh and dry weight. Seedlings were transferred to greenhouse conditions and successfully acclimatized, further developing into normal plants with over 90 % survival. Comparative analysis of seedlings from control and vitrified seeds using flow cytometry indicated that no change in ploidy levels occurred as a result of cryopreservation, therefore maintaining seedlings genetic stability. In this study, vitrification with PVS2 for 120 min with the addition of 1 % phloroglucinol offers a simple, safe, and feasible protocol for cryopreservation of O. flexuosum mature seeds. © 2013 Springer Science+Business Media Dordrecht.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Tillandsia gardneri Lindi, is a herbaceous perennial with ornamental value. However, in Brazil there is no report about this species' cultivation on a commercial scale. The low multiplication rate of T. gardneri (in average one offshoot/plant/year) leads to illegal over-collection in the wild to meet commercial demands. The development of protocols for in vitro propagation of T. gardneri may be useful for increasing multiplication rate, producing enough plants to supply the ornamental market and also to reduce the pressure over plants collection in the wild. The present study evaluated the effect of growth regulators (6-benzylaminopurine-BA alone or in combinations with naphthaleneacetic acid-NAA) on shoots development from seedlings pre-established in vitro, from seed germination on 1/4 MS medium without growth regulators. Seedlings (with about 1.0 cm long) were re-cultured to solid 1/2 MS media supplemented with growth regulators. After 30 days on the induction medium seedlings were re-cultured to MS basal medium. The experiment was conducted in a complete randomized design with four replications and ten treatments: control (free of growth regulators), BA (0.5, 1.0 and 2.0 mg/L), BA (0.5 mg/L) + ANA (0.1 mg/L), BA (1.0 mg/L) + ANA (0.1 mg/L), BA (1.0 mg/L) + ANA (0.5 mg/L), BA (2.0 mg/L) + ANA (0.1 mg/L), BA (2.0 mg/L) + ANA (0.5 mg/L), and BA (2.0 mg/L) + ANA (1.0 mg/L). The outgrowth of shoots did not occur on medium devoid of growth regulators (control). Regression analysis for some evaluated parameters, such as percentage of seedlings responsive to shoot formation and number of shoots/seedling, and regulators concentrations (BA or ANA) were significant, allowing the establishment of the growth regulators concentration for obtaining the best multiplication rate. Some seedlings maintained in media with ANA (0.5 or 1.0 mg/L) were completely converted into callus masses that turned dark brown leading to seedlings death.
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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.
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Irregular production is a major problem in mango. In an attempt to overcome irregular bearing, effects of two antigibberellins on flowering were evaluated, uniconazole (0.25 g of active ingredient per meter of canopy tree diameter) and paclobutrazol (1.0 g of active ingredient per meter of canopy tree diameter). Treatments were applied as a soil drench using 2 L of solution per tree, in a commercial orchard of 'Tommy Atkins' mango. Treatments were applied after the second vegetative flush commenced, subsequent to pruning. Branch growth was evaluated every 30 days after treatment application up to a maximum period of 90 days. The flowering percentage was recorded at 130 days. Ammonium nitrate (NH4NO3) as a foliar spray (concentration of 0.75%) was applied five times at seven day intervals from 95 to 100 days after treatment application as a dormancy breaking treatment. It was found that both paclobutrazol (PBZ) and uniconazole (UCZ) significantly inhibited the development of vegetative growth compared to the control. Both treatments resulted in identical rates of flowering shoots, 87%; based on results, it can be concluded that the application of antigibberellins (PBZ and UCZ) inhibit vegetative development in mango 'Tommy Atkins', and promote high levels of flowering. Additional tests are being carried out in other farms to confirm these findings, for different cultivars and seasons. © ISHS 2013.
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Paclobutrazol applied to the soil is used for the production management of mango in most of orchards on the semiarid region. However, it is necessary to identify other plant growth regulators that might be applied to the leaves, so as to minimize the risk of residues in the soil and plant. The present paper has the purpose to evaluate the effect of plant regulators in the management of vegetative growth on mangoes 'Tommy Atkins'. Three plant growth regulators, sprayed to the leaves, were evaluated: prohexadione-Ca, ethyl-trinexapac and chlormequat chloride, applied in two dosages, and compared to paclobutrazol applied to the soil. In order to compare the effects of the treatment, data were recorded on the vegetative growth (number and length of the shoots). Furthermore, the levels of gibberellins in the apical area of the shoots of 'Tommy Atkins' were quantified, from the beginning of the experiment until the beginning of floral induction. The results showed that sprayings with prohexadione-Ca, trinexapac-ethyl and chlormequat chloride in a dosage of 1.5 g a.i. plant-1 plant was as efficient as a dose of 4.0 g a.i. plant-1 of paclobutrazol applied to the soil, regarding the regulation of vegetative growth of 'Tommy Atkins'. © ISHS 2013.
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The aim of this study was to evaluate the growth and yield of soybean cultivar M-8766 in consortium with Brachiaria brizantha. BRS Piata and Brachiaria ruziziensis at different densities and sowing dates. The experimental design was randomized blocks with treatments arranged in a factorial 2 × 2 × 3 with four replications. Used as factors grass species (Brachiaria brizantha Piata and Brachiaria ruziziensis BRS) intercropped with soybean M-8766, sowing dates (12 and 24 days after soybean emergence) and three seeding rates (0, 5, 10 kg ha-1 of seed). At 71 days after soybean emergence were evaluated plant height, stem diameter, dry mass of leaves, stems and shoots, and 4 months after sowing determined the weight of 100 grains and soybean yield. The results showed that when seeded at a density of 10 kg ha-1 at 12 and 24 DAE soy, Brachiaria brizantha. BRS Piata caused reduction in yield in the order of 6.71% and 3.03% respectively, while the Brachiaria ruziziensis was one that caused a greater reduction in productivity in the order of 13.42 and 16.23%, respectively, of these values expression when considering the price of soybean sack. B. ruziziensis expressed less competitive with soybean. However, the large biomass production of this grass provides deployment system till the next harvest.
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The way of applying zinc can influence the zinc uptake and productivity of crops, especially cereals that have high demand for this nutrient. The aim of this study is to evaluate methods of Zn application on soil, nutritional status and productivity of maize. For this, an experiment was undertaken at FCAV/UNESP, Jaboticabal-SP, in Oxisol clay (DTPA on Zn: 0.5 mg dm-3) with maize (hybrid Simple Impact), from December through May 2009. Nine treatments with three doses of Zn in soil banded application (in furrows) and three doses of Zn by incorporation in soil (0-20 cm depth), foliar application, seed application and control (no Zn). The treatments were arranged in a randomized block design with four replications. Regardless of the method, Zn application promoted higher contents of this micronutrient in soil and higher accumulation in the shoots as well as increasing Zn in the maize grain. However, it did not affect the nutritional status and yield of the maize. The Zn application in the soil resulted in a greater Zn uptake by plants and maize yield, compared to Zn application in the plant by seed or foliar.
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Pós-graduação em Microbiologia Agropecuária - FCAV
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)