خيارات البحث
النتائج 581 - 590 من 2,330
DEGRADAÇÃO DA CAATINGA: UMA INVESTIGAÇÃO ECOGEOGRÁFICA
2009
Jose Jakson Amancio Alves | Maria Aparecida de Araújo | Sebastiana Santos do Nascimento
The domain geographical ecology of the caatinga occupies an area of about 750.000 Km² and it includes parts of the territories the states of Maranhão, Piauí, Ceará, Rio Grande do Norte, Pernambuco, Paraíba, Alagoas, Sergipe, Bahia and part of Minas Gerais. Its area corresponds at 54% of the Northeast and 11% of the brazilian territory and it constitutes it calling Polygon of the Droughts. The use of the caatinga as extensive pasture comes causing strong degradations and for irreversible times in that ecosystem. They are already found extensive areas whose vegetation already meets very impoverished; having lost the diversification vegetation that is it typical. Even so, the regeneration cannot almost always happen because of the intense and constant human pressure. This, once ceased, it would allow, the medium or long term, that the vegetation if it reconstituted. So that that was possible it would be precise to take in bill the factors such geographical ecology as: location, soil types, rock-mother, indexes precipitation and duration of the station evaporates. Of what concisely was exposed, it can be ended that the degrading activities as, especially the extensive cattle creation, contributed to structural alterations of the caatinga and that these they are reflected in its polymorphism, but they are not the only factors. However that was the purpose of that work of presenting a vision geographical ecology of the caatinga submitted to the human, special activity the cattle creation, and the consequences impacts for the vegetable covering in the semi-arid brazilian.
اظهر المزيد [+] اقل [-]AVALIAÇÃO DE PARÂMETROS DE QUALIDADE FÍSICO-QUÍMICOS DE POLPAS CONGELADAS DE ABACAXI, ACEROLA, CAJÁ E CAJU
2009
Antônio José Ferreira Gadelha | Clarice Oliveira da Rocha | Fernando Fernandes Vieira | George do Nascimento Ribeiro
In food analysis, it is of utmost importance the determination of a specific component of the food as it is the case of the determination of the centesimal composition. Are procedures carried through with the purpose to supply information on the chemical composition, physicist-chemistry and, or, physics of a food. It can have different purposes, as: nutritional evaluation of a product; quality control of the food; development of new products and the monitoration of the legislation. In such a way, this work was carried through with intention to -chemical evaluate physicist the quality of pulps congealed with regard to the effective norms of the product. It was verified that, in a generalized manner, the pulps had taken care of the Brazilian legislation, excepting the values of pH and soluble solids (ºBrix) of the cashew pulp.
اظهر المزيد [+] اقل [-]FERTIRRIGAÇÃO COM VINHAÇA E SEUS EFEITOS SOBRE EVOLUÇÃO E LIBERAÇÃO DE CO2 NO SOLO
2009
Tânia Marta Carvalho dos Santos | Márcio Aurélio Lins dos Santos | Cícero Gomes dos Santos | Valdevan Rosendo dos Santos | Dayse dos Santos Pacheco
With base in the context, the objective of the present work was to study the effect of the fertirrigation of the vinasse and to accompany the decomposition of the same incorporate to the soil, in evolution terms and liberation of CO2. They were appraised effects of the application with in nature vinasse on the soil, where the same was treated with three vinhaça levels: 200, 400 and 600m3.ha-1), with humidity maintained around 70% of the capacity of retention of water. For the liberation of CO2 they were made precipitations and titulation with HCl to 1N. Considering by base the appraised levels, the study lead to the following conclusions: 1. After the in nature vinasse addition they didn't detect significant differences in the amount of CO2 liberated by the microorganisms to the 30 and 90 days of incubation; 2. The analyses of the results for 60 days of incubation had significant alterations, where it was verified that there was a reduction in the amount of liberated CO2 of 51 and 42,5% in the respective levels of 200 and 400 m3.ha-1, an increment of 63% was also detected for the level of 600 m3.ha-1; 3. However for 120 days of incubation the in nature vinasse addition provoked significant alterations with increment in the liberation of CO2 78,3; 38,7 and 72,6% for 200, 400 and 600m3.ha-1 respectively.
اظهر المزيد [+] اقل [-]ABSORÇÃO DE NUTRIENTES EM MUDAS DE BERINJELA CULTIVADAS EM PÓ DE COCO VERDE
2009
Alexandre Bosco Oliveira | Fernando Felipe Ferreyra Hernandez | Raimundo Nonato de Assis Júnior
This study aimed to carry through chemical caracterization of the coconut fiber powder and evaluate its effect on the absorption of nutrients in the as medium substrate on the production of eggplant seedling. The experiment was conducted for forty days under greenhouse, and it was used seeds of the Florida Market cultivar were cultivated in polyetilene strays with 54 cells and irrigated with nutritive solution two times for day. The substrates were used dust and fiber green coconut coir fibre, in the proportions of 100% of dust, 75% of dust + 25% of fiber and 50% of dust + 50% of fiber, washed and not washed; dry coconut coir fibre not washed; rind of green coconut grinded (fiber and dust mix from machine) washed end not washed (fiber and dust mix from machine); commercial substrate not fertilized and control (green coconut coir fibre not washed and not fertilized). It was used a statistical randomized block design with eleven treatments and four replications, with 25 plants per replications. The chemical characterization of substrates was carried through and was valuated nutrient total contents of the plant upper parts. The best results were observed for the seedlings grown in dry coconut coir fibre not washed, followed by commercial substrate and green coconut coir fibre washed.
اظهر المزيد [+] اقل [-]FOLIAR NUTRIENT CONTENTS AND FRUIT YIELD IN CUSTARD APPLE PROGENIES
2009
Paulo Sérgio Lima e Silva | Thiago de Araújo Sousa | Keny Henrique Mariguele | Khadidja Dantas Rocha de Lima | Paulo Igor Barbosa e Silva
Foliar nutrient contents are evaluated in several fruit trees with many objectives. Leaf analysis constitutes a way of evaluating the nutritional requirements of crops. Due to the positive impact that fertilizers have on crop yields, researchers frequently try to evaluate the correlations between yield and foliar nutrient contents. This work's objective was to present fruit yields from the 4th to the 6th cropping seasons, evaluate foliar nutrient contents (on the 5th cropping season), and estimate the correlations between these two groups of traits for 20 half-sibling custard apple tree progenies. The progenies were evaluated in a random block design with five replicates and four plants per plot. One hundred leaves were collected from the middle third of the canopy (in height) of each of four plants in each plot. The leaves were collected haphazardly, i.e., in a random manner, but without using a drawing mechanism. In the analysis of variance, the nutrient concentrations in the leaves from plants of each plot were represented by the average of four plants in the plot. Fruit yield in the various progenies did not depend on cropping season; progeny A4 was the most productive. No Spearman correlation was found between leaf nutrient concentrations and fruit yield. Increased nutrient concentrations in the leaves were progeny-dependent, i.e., with regard to Na (progenies FE5 and JG1), Ca (progeny A4), Mg (progeny SM7), N (progeny A3), P (progeny M), and K contents (progeny JG3). Spearman's correlation was negative between Na-Mg, Na-Ca, and Mg-P contents, and positive between Mg-Ca and N-K contents.
اظهر المزيد [+] اقل [-]CORRELAÇÕES ENTRE CARACTERÍSTICAS DE MELOEIRO
2008
Glauber Henrique de Sousa Nunes | Anne Katherine de Araújo Barros | Manoel Abílio de Queiroz | Rogério Alexandrino da Silva | Lonjoré Leocádio de Lima
O objective this work was to estimated genotypic, phenotypic and environmental among traits of melon. Six hybrids of melon and their fifteen populations in diallel crosses were evaluated in a randomized complete block design with three replications. The traits assessed were yield, number total of fruits, average fruit weight, longitudinal diameter, transversal diameter, pulp thickness, pulp firmness and soluble solids content. The correlations between yield and total number fruit and yield and average fruit weight were positives. The total number exhibited negative correlation with average fruit weight and solids soluble content. The correlations of the solids soluble content with average fruit weight, pulp thickness and pulp firmness ware positives. However, pulp firmness and pulp thickness exhibited association negative. The undesirable associations detected in the present work were not sufficiently strong, indicating that is possible to obtain recombinants individuals in the segregating populations evaluated.
اظهر المزيد [+] اقل [-]ALELOPATIA DE Arctium minus BERNH (ASTERACEAE) NA GERMINAÇÃO E CRESCIMENTO RADICULAR DE SORGO E PEPINO
2008
Valdenir José Belinelo | Márcio Paulo Czepak | Sidney Augusto Vieira Filho | Luis Fernando Tavares de Menezes | Claúdia Masrouah Jamal
The objectives of this work were identified and characterize the allelopatic activity of extracts obtained from Arctium minus (Hill) Bernh (Asteraceae). The fitotoxic activity of organic extracts (1 e 100 mg.L-1) and aqueous extract (5,00 e 0,05% m/v) on the germination and radicular growth of the monocotyledon Sorghum bicolor L. (sorghum), and the dicotyledon Cucumis sativus L. (cucumber) were evaluated. The results showed the presence of allelopatic activity variable in according to the extract concentration and with the target plant. The intensity of induced inhibitory effect was higher for the ethanolic extract in concentration of 100 mg.L-1 for Sorghum bicolor L. The results also indicates the existence of the potential use of Arctium minus (Hill) Bernh ethanolic extract as a natural herbicide and open perspectives for the research of the constituent(s) with higher allelopatic activity.
اظهر المزيد [+] اقل [-]INTERAÇÃO GENÓTIPO x AMBIENTE EM MELANCIA NO ESTADO DO RIO GRANDE DO NORTE
2008
José Robson da Silva | Glauber Henrique de Sousa Nunes | Maria Zuleide de Negreiros | Joge Ferreira Torres | Mara Suyane Marques Dantas
The present work aimed to study the environment genotype interaction and estimate the componentssimple and complex of interaction as well as identify watermelon cultivars with phenotypic stability. Seven cultivars of watermelon were evaluated in six environments during the years of 1996, 1997 and 1998 in two location of Rio Grande do Norte State. The trait evaluated was the commercial fruits yield. The interaction Cultivar x Year wasn¿t significant, amount only to 3, 26 % of the total sum of square sum total of the source of variation. There wasn't interaction Cultivar x Location significant, however it explained 11,68 % of the total variation. The triple interaction was significant and explained 13,67 % of the total observed variation. The simple component was responsible for the most part of Cultivar x Environment interaction with about 61% of the total variation. The hybrid Jetstream had the best perfeormance with linear regression coeficient equal to unit, with regression deviation not significant, high coeficient of determination and average yield above the check.
اظهر المزيد [+] اقل [-]ISOTERMAS DE ADSORÇÃO DE COBRE POR BENTONITA
2008
Gilvanise Alves Tito | Lúcia Helena Garófalo Chaves | Susane Ribeiro | Ramara Sena Souza
In environmental studies is important to know the adsorption process of heavy metals in clay minerals, since they are able to immobilize these metals. Knowing the cations adsorption is influenced for several factors, the objective of this research was to study the copper adsorption process by bentonite clay and to evaluate the electrolyte type and pH influence on this process. In order to quantify the adsorbed copper, 2 g of bentonite clay were equilibrated for 24 hours with 20 mL of a NaNO3 (0,01 mol L-1) solution and with 20 mL of water containing different quantities of copper (5, 10, 20, 40, 60, 80, 100,120 mg L-1) as background solutions of pH values 4 and 6. Langmuir's adsorption equation in its linearized form was applied and the values of the maximum capacity and those of the constant related to the bonding energy were obtained. Langmuir isotherms presented two distinct adsorption regions at both pH 4 and pH 6, showing that the adsorptive phenomenon occurs in two distinct stages. The adsorption of copper depends on pH and ionic strength and it increased with an increase in pH and decreased slightly with an increase in ionic strength. The maximum capacity of adsorption and the bonding energy varied with the pH, with electrolyte used and with the adsorption regions.
اظهر المزيد [+] اقل [-]COMPORTAMENTO EQÜINO DURANTE O PERÍODO DE ÓCIO COM DIETAS DE DIFERENTES QUALIDADES NUTRICIONAIS
2008
Leonir Bueno Ribeiro | Carlos Eduardo Furtado | Cleiton Luiz Tonello | Orlando Rus Barbosa | Roberta Ariboni Brandi
The objective was to evaluate the horse behavior during the total time at leisure in testing of metabolism. Four male crossbred horses, with average age of eight years and alive weight of 376,09 kg, were used in an experimental delineation in Latin square (4 x 4), lodged in individual boxes. The treatments had been constituted by four diets: Alfalfa hay + Concentrated (ACSP); Tifton hay (low nutritional quality) + Concentrated (TCSP); Tifton hay (low nutritional quality) + Concentrated with Probiotic (TCCP); Alfalfa hay + Concentrated with Probiotic (ACCP). It was observed a statistical difference (P<0.05) in the percentages of total resting time, alert and head low, in the (ACSP) treatment, showing elevate value 76,85; 4,65 and 1.49%, respectively. The inquietude either showed a significative difference (P<0.05) showing values 5.29% for (ACCP) and (TCCP), respectively. The alimentary activities either showed a statistical difference (P<0.05) for (ACSP and ACCP), showing 10,45% average values. During prolonged resting times, the appeared of behavior disturbs were evident.
اظهر المزيد [+] اقل [-]