Ecosystem's aquatic metabolism comprises three main levels: production, consumption and decomposition. For the aquaculture fundament the knowledge and accompaniment of the biotic and abiotic factors for a sustainable production. The study evaluated the dynamics of variables limnologics in ponds: Colossoma macropomun (CM) and Pseudoplatystoma corruscans (PC), during a 24hs. The work was accomplished in the Station of Fish farming of Chesf, Paulo Afonso-BA. The variables oxygen (O2), temperature (T°C) and pH were measured every two hours, shines and transparency. Samples of water were analysis ammonia, nitrite, nitrate, inorganic and organic phosphate, total phosphors, chlorophyll a, identification of the plankton and phytobenthos were collected at 09:00, 15:00 and 21:00hs. All the variables physical-chemistries were inside of the ideal for culture species. The group phytoplankton most frequent no CM was Cyanophyta and Bacillariophyta. while in PC was Xanthophyta. The group phytobentic most frequent no CM was Xanthophyta, while in PC was Bacillariophyta. The group of Copepods was the most evident zooplankton in CM and there was absence of Rotifers in PC.

The soil fertility and plant nutrition are influenced by electrochemical reactions occurring on the surface of soil colloids. The point of zero salt effect (PZSE) is an important parameter to study the surface charge of those colloids, since, it allows to determine the net surface charge of soil particles. This paper aimed to determine the PZSE and the net electrical charge of twelve soils from Paraíba State, which samples were collected at the depth of 0-30 cm. The point of zero salt effect was determined using program computational PZSE for Windows version 1.0. The method adopted was the potentiometric titration with different ionic strength using electrolyte NaCl in concentrations 0.1; 0.01 and 0.001 M. The use of the program has a better analysis and accuracy of the values obtained for the PZSE, which ranged from 3.06 to 5.41. All soils had values of PZSE smaller than the pH in water, being, therefore, electronegative. All soils had the potential and the electrical charge negative, possibly due to the effect of organic matter once it presented significant correlation with PZSE.

Corn yield losses caused by weeds may reach up to 80%. Reducing the use of herbicides is one of agriculture's major goals and several alternatives are currently being investigated, including intercropping. In the Brazilian Northeast, corn intercropping with cowpea (Vigna unguiculata (L.) Walp.) is extensively practiced, and there is interest in evaluating weed control under this type of intercropping. The objective of this work was to evaluate the effects of different cowpea planting times, intercropped with corn, on green ear yield of two corn cultivars. The experiment was carried out under randomized design blocks with four replications. AG 1051 and AG 2060 corn cultivars were submitted to the following treatments: no hoeing, two hoeings (20 and 40 days after planting), and cowpea planting (BR 4 - Mulato cultivar, with indeterminate growth) at corn planting and at 5, 10, and 15 days later. Twenty-eight weed species were found in the experiment area. In all characteristics evaluated, except for plant height, ear height, and total number of green ears, where no difference occurred between treatments, the lack of weeding determined the smallest means, while weed control determined the highest. In plots where cowpea was sown, intermediate means were obtained for number and weight of marketable unhusked green ears and for number and weight of marketable husked ears. This suggests that cowpea controlled weeds to a certain extent, especially when it is planted earlier, which was, however, insufficient to avoid green ears yield loss. The corn cultivars evaluated were not different among themselves, except with regard to ear height. The cowpea grain yields were practically null in all plots.

Espinheira Santa (Maytenus truncata Reis) it is a plant used for medicinal ends in the hiperacidez treatment, gastric ulcerations, cutaneous disease as, eczems, constipation and cancers. She possesses properties analgesic, antiseptic and healing, being found in the proximities of Rio de Contas in Jequié - BA. Due to the intense use for the population and exploration for the erveiros, the species is disappearing of the area. With that, it is made to study the species in molecular level seeking to subsidize a strategy of protection of the same. Aiming at to evaluate and to adapt a methodology as tool to be used in studies of molecular biology was tested four protocols of extraction of DNA, and the protocol that obtained the best results in the tests of quantification of DNA in agarose gel and photometer spectrum was it of Ferreira & Grattapaglia (1998) with modifications in the act of the maceration and of the centrifugation. DNA was isolated I integrate and in great been presenting in it measured a degree of purity (A260/A280) in photometer spectrum of 1,78 and a concentration of 1846 ng/ml.

This assay was conducted at the Departamento Ciências Vegetais of Universidade Federal Rural do Semi-Árido, with the objective to evaluate the tolerance of the jitirana (aegyptia Merremia L.), in saline solution. The used experimental delineation was the inteiramento casualizado with four treatments and four repetitions. The treatments had evidenced of four levels of salinity: testemunha (0,614ds/m) and the three saline solutions the 10, 20 and 30ds/m. The seeds had been incubadas in the sand esterilizada in caixotes wooden with capacity of 100 sementes.O parameter germination percentage were used as identification character of resistance. Ahead of the displayed one one concludes that the jitirana is tolerant the salinity since the same dS/m came to present reduction in the germination only in the C.E=30.

This work had as objective studying the extraction of cadmium and evaluate four extractors as conventional chemical: Mehlich-1, Mehlich-3, TEA-DTPA and CaCl2 as indicators of the availability of cadmium in plants (Zea mays) in soils of the state of Rio Grande do Norte. The soils were submitted to the correction of pH and chemical and physical analysis. The determination of total cadmium in samples of soil, were made through the technique of digestion digesters in tubes containing nitric acid with the ratio of 3:1 v / v (aqua regia). The extracts were read by the atomic absorption spectrometry, setting up the total concentration of cadmium in the samples. For the extraction of cadmium in the plant samples were submitted to digestion nitric-perclórica will ratio of 3:1 (v / v). Statistical analyses were made in the programme Statistic 6.0, where the data were submitted to the analysis of variance and correlation, is adopting levels of significance of 1% and 5% probability. The capacidae recovery of extractors used followed the following order: Water Régia> Mehlich-1> Mehlich-3> DTPA-TEA> CaCl2. The aqua regia was a good extractor for phytoavailability, presenting the second highest correlation coefficient. The CaCl2 was given the best extractor due to the availability has presented better correlation between the cadmium content in dry plant maize and extracted by extratoras tested solutions. On average the Neossolo Quartzarênico led to better absorption of cadmium by plants of maize and Neossolo Flúvico and Haplic Cambisol the minors.

In order to determinate the floristic check-list of a inselberg at the Fazenda Timbaúba (35o52'50.3", 7o1'0.8"), municipality of Esperança/PB, Agreste da Borborema Microregion, were realized the present study. The inselberg flora comprise 127 species, 101 genera and 53 families of wich the Leguminosae family with 17 species showed the higher richness, followed by the Asteraceae (9 spp.), Poaceae (7 spp.), Euphorbiaceae and Orchidaceae (6 spp.) families. Bromeliaceae and Cactaceae, despite of not be the higher richness, are covering extents areas, suggesting a higher importance for those families in inselbergs colonization. Comparing the families with other inselberg floras, 29 of them also were raising in Quixadá/CE, 28 in Pão de Açúcar and 24 in Serra do Mar/RJ inselbergs. The majority of species showed xenomorphic adaptations due hydric stress observed in the Southern and Northeastern Brazilian inselbergs. The differences in the floristic composition, especially at genus and species level seem to result of different speciation pressure what aid the taxa with better adaptation at these environments.

The knowledge of the parameters of the growth of a culture is of fundamental importance for a rational and efficient nutritional handling. An experiment was carried out during the period of october to december of 2005, in farm of the producing melons region of Assu-Mossoró, with the objective of analyzing the growth of the melon plant Gália fertirrigation with different doses of nitrogen and potassium. The randomized blocks in a factorial scheme (3 x 3), with three replications. The Treatments consisted of combination the three nitrogen doses (N1-42, N2-84 e N3-126 kg ha-1) and potassium (K1-106, K2-212 e K3-322 kg ha-1), being the levels N2 e K2 are most recommended in technical literature, applied for fertirrigation with different irrigation depths (L1 = 1,1.NTI, L2 = 0,9.NTI and L3 = 0,7.NTI). The appraised variables were index of leaf area (IAF), matter dries of the aerial part (MSPA) and the reason of leaf area (RLA). The index of leaf area and I accumulate it of matter dries can be dear for equations polynomials of the second degree. The index of leaf area and the matter accumulation dries were influenced positively by the increment in the doses of applied nutrients and for the irrigation depths. The reason of leaf area of the melon plant is reduced during the cycle of the culture, being influenced by the irrigation depths than for the levels of nitrogen and potassium.

Manihot pseudoglasiovii is considered an excellent forage, as for its nutritional value as for the high degree of palatability. Like as other native plants of the semiarid regions it, can be considered a resource of important strategical use. It is an alternative not only for the dry period the entire year, in a conservation system. This work had as objective of study the growthof maniçoba in relation is density (1,5 x 1,5 and 2 x 2) and fertilization (manure of bovine, goat/sheep and without fertilization). It was used an experimental desing of blocks casualizaed with treatments distributed in 2 x 3 factorial. The experiment was out through in the Department of Zootecnia of Center of Agrarian Sciences of the UFPB, in Campus II in Areia-PB. There had been evaluated morphologic characteristic (Height of plant, diameter of caule, area of the pantry, leaf number and number of bifurcations) and productive characteristic (leaf production, production of branches, production of total fitomass substance and total dry substance)The analyses of variance were made employng the SAEG program. The and analyses of regression of the morfological characteristics on the time. Were mande visig SAEG program too. In accordance with the results obtaimed in this study, the different densities had not presented significant difference. However by total production for area the results were favorable to the higher density (1.5 x 1.5). Already the fertilizations with bovine and goat/sheep manures, although had shown no between them difference, had present statistical difference from treatment without fertilization, shoung higher pr.

Physiognomic parameters and floristic composition of woody plants were compared in four areas located in three different physiognomies of caatinga (sensu stricto): two shrub-arboreal caatingas, one in Fasa farm (FA), and the other in Poço do Ferro farm (PF), Floresta municipality, and one arboreal (BE) and one open arboreal (BD) caatinga, both in Boa Vista farm, at Custódia municipality, Pernambuco state. All alive and standing dead plants with total height ¿ 1 m and stem diameter at soil level ¿ 3 cm present in twenty-five 10 x 10 m plots, in each area, were sampled. Lianas and bromeliads were excluded. Sixty one species, belonging to 41 genera and 21 families, were found in the four areas, being 27, 27, 26 and 30 species in FA, PF, BE and BD, respectively. They had densities of 1876, 2172, 1076 and 1872 plant/ ha and basal areas of 16.51, 14.62, 34.29 and 20.28 m2/ ha, respectively. The patterns individualize tree physiognomies: arboreal, open arboreal and shrub-arboreal. Independent of the physiognomy, the woody floras of the four areas were similar to those of other areas of caatinga sensu stricto, located in the large sertaneja depression region, with some particularitities defined for each specific habitat.