The objective of the present study was to evaluate the effects of different pre-treatments on the germination of the seeds as well as the emergence velocity of the seedlings of Erythrina velutina and Erythrina falcata. The treatments utilized for the evaluation of germination were intact seeds (control); mechanical scarification with sandpaper number 120 in the opposite side of the embryo; and immersion in water at room temperature for 6, 12, 24 and 48 hours. Four replications of 25 seeds each were used per treatment and the experimental design was completely randomized, and the comparison among the averages was made using the Tukey test at 5% of probability. The percentage of germination, the emergence velocity index and the relative frequency of germination were calculated 31 days after sowing. For both species, better percentages of germination and values of emergence velocity were obtained with the mechanical scarification of seeds. That treatment was efficient in the uniformization and anticipation of the germination process. However, the tests done with seed immersion in water at room temperature for up to 48 hours do not increase the percentage of germination of E. velutina and E. falcata seeds.

The accelerated process of environmental degradation in the São Francisco Drainage Basin (BHSF) has generated a high demand for seeds destined to the production of plant propagules. However there is no information about the commercial value of the diaspores of forest species which occur in the BHSF. The objective of this study is to propose a system to evaluate the worthiness of the kilogram of seeds for 22 plant species of the Caatinga, based in the following parameters: geographic distribution, endemism, level of threat, functional group, processing, collection effort, classification of seeds and number of seeds per kilogram. Field studies were conducted in five municipalities of the the region of the central valley of the São Francisco River and on five islands located in the main channel of the São Francisco River, from August 2007 to September 2008. The prices calculated using our system varied from R$ 10.00 for Syagrus coronata Mart. Becc. (Arecaceae) and R$ 44.15 for Handroanthus spongiosus (Rizzini) S.O.Grose (Bignoniaceae). From a 50% cut percentage in a cluster multivariate analysis we identified the occurrence of three groups: a group with seeds of lesser commercial value (average value of R$ 18.80.Kg-1), a second group with intermediate commercial value (R$ 28.21.Kg-1) and a third group with seeds of higher commercial value (R$ 32.85.Kg-1). We hope that this study will contribute to the process of conservation and ecological restoration of Caatinga, and also to the improvement of the socio-economic conditions of the local population from the commercialization of these seeds.

The use of phosphates fertilizers can increase the trace element concentration in the soils, with an eventual transfer to human chain food. As indispensable tool, models can be used to identify the risks and to evaluate the effects of preventive actions. The goal of this study was to applied a mass model for trace elements, developed at the University of California - Riverside, (USA) in two cerrado soils (LVdf, a clayey soil and NQ, a Sandy Soil). The model was used as an instrument to evaluate the risks of cadmium and lead accumulation in different soils and in soybean plants, upon the application of different phosphorous sources in the soils. The simulate cadmium content after ten years of application of the reactive phosphate FR3, it reached 2.97 mg kg-1 in the LVdf. The cadmium content in the RQo was more available for the soybean plants. The model showed a greater accumulation of Cd and Pb in the clayey soil (LVdf), after ten years of application high doses of these elements through the phosphates fertilizers FR3 and FN2.

The knowledge about the magnitude of the genetic variability of collection is great importance to the success and longevity of plant breeding programs. Same authors affirm to exist genetic variability in elephant grass (Pennisetum purpureum), being expanded with the use of millet (P. glaucum) in the hybridization. This work presents considerations on genetic variability in elephant grass germplasm and the main methodologies used to assess this variability. Based on the works studied, the methodologies (principal component, canonical variables and agglomerative methods, based in the euclidian and Mahalanobis distances; Jaccard' index and cluster' methods, based in the Ney & Li distances) were efficient in to determine the genetic variability in most genotypes studies in Brazil and other countries, both biometric and molecular level, way be exploited by breeding programs through methods of selection intra and interspecific hybridizations.

This work aimed to evaluate the effect of the use of calcium nitrate on the reduction of stress in the melon plants exposed to excess salt in the irrigation water. The experiment was carried out at the Centro de Ciências e Tecnologia Agroalimentar (CCTA/UFCG), Pombal-PB, from 09/19/2009 to 11/20/2009, using the hybrid melon 'Hales Best Jumbo'. The treatments consisted of the use of two levels of salinity of the irrigation water (0.3 and 5.0 dS m-1) versus rates of N in the form of calcium nitrate (5.5; 6.25; 7.0; 8.5 g N per plant). The experimental design was in randomized blocks, in factorial scheme 2x4, with four repetitions. The highest rates of photosynthesis, stomatic conductivity, transpiration, leaf area, total dry mass and the fruit yield per plant were observed in melon plants irrigated with water of low salinity (0.3 dS m-1) compared to the ones with the saline water (5.0 dS m-1), and for the rates of N between 6.10 and 8.5g of N per plant for both levels of salinity. The suply of N in the form of calcium nitrate was effective on reducing the stress in melon plant the caused by the salinity of the irrigation water up to the rates of 6.20g of N per plant. In absolute terms we can affirm that the best performance of the melon plant was achieved with the dose of 6.25g of N per plant when irrigated with water of low salinity.

This study aimed to evaluate the influence of S. platensis as a food supplement for Nile tilapia post-larvae. Two trials was running. In the first, was used two treatments, one offered freshwater microalgae (green water) and other offered microalga S. platensis. In the second trial, were evaluated the effect of without copepods, administration of copepods alone and copepods enriched with S. platensis. Throughout the study, all animals were fed diets with masculinizing hormone 17-K-methyl-testosterone. It was evaluated the growth in weight and length, the survival rate and the rate of sex reversal of tilapia (mean +,- SD). In the first trial, the fish that received the S. platensis and receiving freshwater microalgae showed as result, 0.21 +,- 0.042 g; 2.50 +,- 0.091 cm; 97.5 ± 1,00% and 0.11 +,- 0.022 g; 1.91 +,- 0.419 cm; 98.33 +,- 0.70%, respectively. In the second trial, when the copepods were utilized, with and without S. platensis, the post-larvae as result, 0.221 ± 0.008 g; 2.70 ± 0.070 cm; 86.67 +,- 1.03% and 0.211 +,- 0.014 g; 2.56 ± 0.121 cm; 77.50 +,- 1.33%, respectively. The animals that received only commercial had as result, 0.190 +,- 0.008 g; 2.22 +,- 0.215 cm and 79.17 +,-0.21%. Using S. platensis resulted in better growth in weight and length, but did not affect survival and rates of sex reversal Nile tilapia post-larvae of exposed to natural food.

The present study was carried out aiming to evaluate the effects of potassium, copper and zinc on the growth and seed yield of castor (Ricinus communis L.), cultivar BRS Nordestina and BRS Paraguaçu. Two experiments were conducted in a greenhouse, in Campina Grande, Paraiba State, Brazil. The experimental was conducted 2 x 2 x 2 factorial design completely randomized amounting in each experiment, a total of 24 experimental units, subjected to the following levels of fertilization: potassium (150 and 250 kg ha-1), copper (16 and 32 mg dm-3) and zinc (32 and 64 mg dm-3). Plant height, stem diameter, number and length of leaves were measured at 21, 42, 62, 82, 102 e 123 days after planting (DAP). Number and weight of seeds were measured. Potassium, copper and zinc did influence BRS Paraguaçu and BRS Nordestina growth and BRS Paraguaçu production. The highest yield of seed weight of BRS Paraguaçu corresponded to 250 kg ha-1 K2O, 16 and 32 mg dm-3 Cu and Zn, respectively.

The objective of this study was to evaluate the utilization effects of two native cacti named mandacaru (Cereus jamacaru DC.) and xiquexique [Pilosocereus gounellei (A. Weber ex K. Schum.) Bly ex Rowl.] associated with sabiá (Mimosa caesalpiniifolia Benth.) and flor de seda (Calotropis procera (Ait.) R.Br.) about the nutrient intake, daily weight gain, and feed conversion in sheep feedlot. Twenty Morada Nova male hair sheep with an average weight of 15.40, were allocated in a randomized block design, with four treatments and five replicates. The experimental treatments consisted of four diets (30% native cacti + 30% shrub hay + 40% concentrate, on dry matter basis): T1- xiquexique + sabiá hay; T2- xiquexique + flor de seda hay; T3- mandacaru + sabiá hay e T4- mandacaru + flor-de-seda hay. The concentrate consisted of 100.0% algaroba (Prosopis juliflora (Sw) DC) pods. No significant difference was observed for daily weight gain which averaged 88.77 g, and also for voluntary intakes of dry matter, organic matter, ether extract, total carbohydrates, nonfiber carbohydrates, total digestible nutrients and digestible energy in relation to g/day, %BW and g/kg0.75. Significant differences were observed for intake of water in g/day.

The aim of this study was to evaluate the production of Freshwater Angelfish (Pterophyllum scalare) in different stocking densities in cages polycultured with Amazon River Prawn (Macrobrachium amazonicum). Four treatments were evaluated (1; 2; 3 and 4 fish.10 L-1) using two ponds and 24 experimental units. Water quality parameter reached adequate levels for the species. Production data were submitted to ANOVA. Fish produced in the lowest density showed higher values of final weight and standard length, and lower total biomass in comparison with the others treatments. Feed conversion rate, survival, batch uniformity and body factor were not significant different among treatments. The highest density tested produced more fish and gross yield than the others treatments. The density 20 fish.10L-1 is recommended to produce Freshwater Angelfish in cages polycultured with Amazon River Prawn.

This work aimed to evaluate the effect of cut height on jurema-preta control. Thus, two trials were carried out, one in September 15th and other in December 15th of 1997. The experimental area had 1,400 m². Treatments were the height cuts of 25; 50; 75 and 100 cm from the soil. Evaluations were done when more than half of plants were showing 50% of their regrowth with a diameter of 0.7 cm. The experimental design was in randomized blocks with split-plot, being the height cut the parcel and the cut the sub-parcel. In the first trial and at the end of the 3rd cut, the higher mortality of 84.6% was found among plants cut at 75 cm and the higher number of regrowth was observed in plants cut at 100 cm, but the stem diameter was not affected by treatments. In the second trial and at the end of the 3rd cut, the higher mortality of 50% was found among plants cut at 100 cm and the other variables were not affected by cut height. The control of jurema-preta may be done in September, cutting the plants at 75 or 100 cm from the soil and always cutting the regrowth plants when they reach 0.7 cm of diameter. The jurema-preta control by standardization cut in December was inefficient regardless the cut height.