990 resultados para Shoot pruning


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The objective of this study was to evaluate the feasibility of the biosolids used as substrate component for seedlings production of Eucalyptus. This way, different proportions of biosolid/carbonized rice (80/20, 70/30, 60/40, 50/05 and 40/60) were tested as substrates in mixture, which were compared to the common substrate used by forest nursery (Multiplant®), as control. The experiment was established with Eucalyptus grandis where growth seedlings-related parameters were assessed: shoot height, collar diameter, accumulation of dry matter on the shoot and root, chemical analysis of the vegetal tissue of aerial part and root, foliar area and chlorophyll content. The results revealed that Eucalypts seedlings developed in substrate with 50% biosolid were similar to the control in relation to the evaluated parameters, concluding that the use of biosolids for seedlings production is quite promising.

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The Brazilian Cartography presents great deficiency in cartographic products updating. This form, Remote Sensins techniques together Digital Processing Images - DPI, are contributing to improve this problem. The Mathematical Morphology theory was used in this work. The principal function was the pruning operator. With its were extracted the interest features that can be used in cartographic process updating. The obtained results are positives and showed the use potential of mathematical morphology theory in cartography, mainly in updating.

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Stryphnodendron adstringens (Mart.) Coville (barbatimão), belonging to Mimosaceae family; it is used as ornamental and the wood is used in civil buildings, edification in wet places, lathe and joinery jobs, being very used also in home-made medicine against hemorrhage, diarrhea, hemorrhoids, conjunctivitis, injury cleaning, uterus hemorrhage, ulcerous hurt and excessive oily skin. The objective of this research was to determine the allelopathic potential of an aqueous extract, boiled or not of S. adstringens (Mart.) Coville, in the Cucumis sativus germination and initial development. Thus, the aqueous vegetable extract was extracted from the shoot, which was triturated in 1L of distilled water to 100g of leaf, being the extract filtrated and separated in boiled and not boiled. The treatments used were distilled water (0%) and boiled and not boiled extracts, in the concentrations of 50 and 100%. The cucumber seeds were put to germinate in Gerbox, having filter paper as substrate, which was wet with 25mL from different treatments, in constant temperature of 25°C. The reading germination was accomplished in breaks of 24 hours, for a period of five consequently days after the beginning of the experiment, considering germinated the seeds that showed 2mm of root, approximately. To dry matter determination, the seedlings with five days after the germination were separated in shoot and root, dried during three days to a constant weight in a 60°C forced draft oven. Through results, it can be concluded that the extract of S. adstringens affected more the Cucumis sativus seedling development than the germination, and it didn't show difference if boiled or not.

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The aim of this study was to evaluate the influence of different types of rhizomes utilized as seed and the effects of mulch in the culture of Turmeric. This work was conducted in the experimental cultivation area of the Universidade de Ribeirão Preto - UNAERP, in Ribeirao Preto, state of Sao Paulo, Brazil from September/1997 to July/1998. The experiments were arranged in a randomized complete block with a factorial arrangement 2x3, design with 4 replications (32 plants each). The treatments consisted of the use of types of rhizomes utilized to proliferation (head and finger) and types of mulch (absent, grass and leaves/branches). This study investigated proliferation (61, 88 and 124 days after installation), length, shooting and number of leaves of the mother plant besides the number of leaves of the shoot (112, 146 and 233 days after installation), number of finger rhizomes and head rhizomes, fresh and dry biomass of rhizomes and the yield of essential oil (after harvest - July 1998). Obtained results showed a great influence of the type of rhizome used to proliferation. Head rhizomes produced, in weight, about 30% more, when compared to plants from finger rhizomes. Mulching almost duplicated rhizome productivity from 2338 kg.ha -1 of dry rhizomes to 4499 kg.ha -1, when rhizome used to proliferation was finger and from 3046 kg.ha -1 to 5943 kg.ha -1, when using head rhizomes. The yield of essential oil did not show any alteration, independently of the treatments realized.

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Micropropagation of Calendula officinalis L. is usually propagated through seeds and therefore shows high diversity in flower size and colour, what causes quantitative and qualitative chemical variability. A micropropagation protocol was established for clonal propagation of this species to achieve homogeneous biomass, more appropriate for the production of phytotherapics. Explants harvested from capitula were the most appropriate for the micropropagation process. MS culture medium supplemented with 1.0 mgL-1 BAP and 6.0 gL-1 Phytagel™ enhanced shoot proliferation, while MS medium supplemented with 0.5 mgL-1 Kinetin and 6.0 gL-1 Phytagel™, increased shoot elongation. Plantlets (80%) cultured in MS/2 medium supplemented with 1.0 mgL-1 de IBA rooted.

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The objective of this work was to evaluate different concentrations of nutritional solution in the hydroponic cultivation of Viola x wittrockiana Gams. The experiment was conducted in DFT hydroponic system, in a completely randomized design with a 5×4 factorial scheme and five nutrient solution concentrations (50, 75, 100, 125 and 150%), four evaluation periods with three replications of three plants for each treatment. Plant height, root length, number of leaves, flowers and floral buttons; fresh and dry weight of shoot and root were determined. The results were submitted to variance analysis, Tukey's test for evaluation periods and regression analysis for nutrient solution. A decrease in the development of the shoot and root was observed with an increase of the number of cultivation days; the greatest number of floral buttons occurred in the third week of cultivation. A reduction in the plant height, root system length, the number of leaves and the fresh and dry weight of shoot was observed generally with the increase of nutrient solution concentration.

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There are several papers on pruning methods in the artificial neural networks area. However, with rare exceptions, none of them presents an appropriate statistical evaluation of such methods. In this article, we proved statistically the ability of some methods to reduce the number of neurons of the hidden layer of a multilayer perceptron neural network (MLP), and to maintain the same landing of classification error of the initial net. They are evaluated seven pruning methods. The experimental investigation was accomplished on five groups of generated data and in two groups of real data. Three variables were accompanied in the study: apparent classification error rate in the test group (REA); number of hidden neurons, obtained after the application of the pruning method; and number of training/retraining epochs, to evaluate the computational effort. The non-parametric Friedman's test was used to do the statistical analysis.

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This paper evaluated the critical level, responsivity and boron use effciency on growth and the biomass production in six Eucalyptus grandis x Eucalyptus urophylla clones (Ca, Cb, Cc, Cd, Ce and Cf). An experiment was carried out in pots containing ground silicon, under greenhouse conditions using four boron rates per solution (0; 0.135; 0.27; 0.54 mg L -1 of B). The treatments were combined in a randomized block experimental design in a 4 × 6 factorial scheme with three replications. Plant height, stem diameter, dry matter production in the shoots of the plant and boron use effciency in the leaves, stem and total dry matter at the 8th month of age were evaluated. Due to boron fertilization, growth and shoot biomass were observed in the Eucalyptus plants after 240 days of being planted in pots. The increases in growth and biomass were 35 to 54% and 21 to 64%, respectively. The boron rates that promoted major growth of the plants were 0.33 to 0.44 mg L -1 of B and in this range the most effcient clone for dry matter production of leaves was Cf and the least effcient one to stem biomass production and the shoot biomass was Cd, no signifcant differences among other clones were observed. The critical level of boron in solution was 0.09 to 0.24 mg L -1 of B in the growth of the plants.

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The aim of this work was to evaluate the effect of soil compaction caused by tractor wheel traffic on the limiting water range (LLWR), shoot growth and levels of compaction and four replications in a completely randomized experimental design. Soil samples with preserved structure were collected in the layers: 0.02-0.05; 0.08-0.11; 0.15-0.18 and 0.22-0.25m to determine macroporosity, microporosity, total porosity, bulk density, resistance to penetration and LLWR. The evaluated corn parameters were: plant and first spike height, steam diameter, number of spikes per plant, plant dry matter, dry matter of 1000 seeds and seed productivity. The soil compaction restricted all corn parameters except the number of spikes per plant and dry matter of 1000 seeds. The LLWR was reduced by the soil resistance to penetration, even in the tilled soil with bulk density of 1.12 Mg m-3. Only the treatment with 11 Mg tractor, repeated four times on the area, demonstrated bulk density above critical bulk density in the LLWR that was 1.37 Mg m-3, where the seed productivity was significantly smaller.

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Caesalpinia ferrea is a species used a lot as a medicinal plant, for urban arborization and landscape design in the state of Amapa. Yet there is not much ecophysiological information available on it. Light is an important environment factor that controls processes associates with the accumulation of dry matter, contributing thus for plant growth. The object of this research was to study the effect of different luminosity levels on the growth of seedlings of this species. The seedlings were transplanted to plastics bags containing a mixture of soil and sand (2:1), which were maintained in the full sun, under artificial shade with reduction of 50% and 70% of the luminosity and under natural shade of a closed canopy of forest. The experimental design was completely randomized with five replicates. Seedlings submitted to natural shade showed strong growth inhibition. In the full sun, the seedlings presented higher net assimilatory rate (NAR), lower shoot/root ratio (SRR) and lower leaf area ratio (LAR). The results showed little difference in the growth and biomass allocation between seedlings kept in 50 and 70% shade; the seedlings submitted to this treatment presented higher values of SRR and LAR. This indicates plasticity which influences a possible increase in light capture and is important, therefore, to keep the seedling growth and survival under low light levels. The results as a whole showed morphological and physiological adjustment to different light levels in Caesalpinia ferrea.

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Soil compaction reduces root growth, affecting the yield, especially in the Southern Coastal Plain of the USA. Simulations of the root restricting layers in greenhouses are necessary to develop mechanisms which alleviate soil compaction problems. The selection of three distinct bulk densities based on the Standard Proctor Test is also an important factor to determine which bulk density restricts root penetration. This experiment was conducted to evaluate cotton (Gossypium hirsutum L.) root volume and root dry matter as a function of soil bulk density and water stress. Three levels of soil density (1.2, 1.4, and 1.6 g cm-3), and two levels of water content (70 and 90% of field capacity) were used. A completely randomized design with four replicates in a 3×2 factorial pattern was used. The results showed that mechanical impedance affected root volume positively with soil bulk density of 1.2 and 1.6 g cm-3, enhancing root growth (P>0.0064). Soil water content reduced root growth as root and shoot growth was higher at 70% field capacity than that at 90% field capacity. Shoot growth was not affected by the increase in soil bulk density and this result suggests that soil bulk density is not a good indicator for measuring mechanical impedance in some soils.

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The effect of phosphorus levels on seedling growth, dry and fresh matter production, and in vivo acid phosphatase activity was studied in Lychnophora ericoides cultivated during 130 days after transplanting in a greenhouse. Experimental design was completely randomized, with four P 2O 5 levels (0; 40; 80; 160 mg dm -3 as triple superphosphate) and five replicates of four plants each. The used soil was dystrophic acid dark red latosol. Lychnophora ericoides is responsive to phosphate fertilization with modification in daily relative growth rate, dry matter production and distribution among the plant parts. Acid phosphatase activity had significant and negative correlation with total, leaf and stem dry matter production, as well as with P levels accumulated in the leaf tissue. On the other hand, acid phosphatase activity had significant and positive correlation with root/shoot ratio.

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Although the management of the coffee crop is well established in Brazil, there is still room for its improvement in relation natural resources available in each region, aiming the increase in productivity. Here are presented results regarding the fate of the fertilizer nitrogen (N) applied to a coffee plantation related to the prevailing soil water conditions. Soil water balances are discussed, which allowed evaluation of the root distribution, determinations of the crop coefficient and of the soil water conditions during the development of the crop. Approximately, 60% of the root system was distributed in the 0-0.3 m soil layer and the average crop coefficient was 1.1 for 3 to 5 year old plants. Using an N label, the 15N, it was possible to study the distribution of N in the plant and in the soil and establishes general N balances, which also include losses like leaching and volatilization. After two years of ammonium sulfate application, at rates of 280 (1st year) and 350 (2nd year) kg.ha-1 of N, in four equal application performed during the period of positive growth rate, the recuperation of fertilizer N were 19.1% by the aerial plant part and 9.4% by the roots, 12.6% remained in the soil and 11.2% in the litter; 0.9% was lost by volatilization and 2.3% by leaching; 26.3% was exported through harvesting and 18.2% remained in non evaluated compartments. From the applied 630 kg.ha -1 of N during the two years, 180 kg.ha -1 of N were found in the plant (shoot and root), which corresponds to 28.6%; 150 kg.ha -1 of N remained available for the next years(soil and litter), and only 20 kg.ha -1 of N were effectively lost (volatilization and leaching).

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The objective of this work was to evaluate the effect of omission of macronutrients in the growth and the nutritional state of elephant-grass plants (Pennisetum purpureum Shum cv. Mott). The experiment was developed in the FCAV/UNESP, in Jaboticabal-SP,Brazil, using nutrient solution. The experimental design was completely randomized blocks, with seven treatments (the complete solution proposed by Hoagland & Amon (1950) and the individual omission of N, P, K, Ca, Mg and S, in these solution), in three repetitions. Pre-germinated plants were placed in pot (5 dm3), containing the nutrient solution, which was aerated constantly during the experimental period and the respective treatments, with three replications each. Weekly, the height of the plants, the leaf number, apex diameter and number of tillers were evaluated as well as plant nutritional state. The omission of N, P, K, Ca, Mg and S limited the production of dry weight of shoot the elephant grass, compared to the full treatment. The deficiency of a macronutrient, in addition to promoting reduction of its content in the shoot, resulted in reducing the accumulation of most macronutrients, with resultant morphological changes, translated as characteristic symptoms of deficiency.

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It was aimed to assess the effects of zinc in the development and nutrition of Tanzania grass. The experimental design used was fully randomized, consisting of six doses of zinc (0, 15, 30, 60, 120 and 240 mg dm'3) and four repetitions. The experimental unit was formed in a vase filled with a Red Latosol dystrophic (Zn = 0.4 mg dm). There were two cuts, the first after 53 days of transplanting seedlings and the second 35 days after the first cut. Was evaluated the concentration of zinc in the soil, the content of zinc leaf, the number of tillers, number of leaves, plant height, the dry mass of the shoot, root system and the whole plant. The doses of zinc influenced the concentration of zinc in soil and plant, and production of dry mass of Tanzania grass, especially the first cut. The Tanzania grass shows high tolerance to the toxicity of zinc, and toxic critical level of 273 mg kg-1.