The research was lead in two experiments with the objective of to identify methods to superation of dormancy in seeds of Leucaena leucocephala, Cunningham variety, and to verify the effect of light and temperatures in germination of this species. In first the seeds were submitted the nine methods to superation of dormancy: immersion in water under ambient temperature during 24, 48 and 72 hours, immersion in hot water under temperatures of 60, 80 and 100oC, immersion in sulfuric acid per 5 and 10 minutes, beyond of the witness. In second experiment, after treatment with sulfuric acid for 10 minutes, the seeds were sowed in tabledoch paper type Germitest and put to germinate under ten combinations: continue light and constant temperature of 20, 25, 30 and 35oC; dark continue and constant temperature of 20, 25, 30 and 35oC; alternated temperature of 20-30 and 25-35, both with fotoperiod of eight hours. Conclusion the specie Leucaena leucocephala presents seeds dormancy, detach-itself the sulfuric acid as efficient method to the superation of dormancy; the seeds of leucena are insensitive to the light and your germination was not influenced by the temperatures useds.

This research had as objective determination the floristic composition and some parameters phytosociological of the herbaceous vegetation of caatinga. The studied area is located in the located in the experiment station of UFPB, in the county of São João do Cariri, Paraíba, Brazil. Three caatinga physionomy were selected where were plots fixed of 10mx10m, an open one and another closed, containing 5 plots of 1m x1m total of 30m². Being a represented by the covering vegetable less conserved (Area I), other constituted by an area in intermediate apprenticeship of conservation (Area II), and the third area being represented by the covering vegetable more conserved (Area III). The herbaceous flora was represented by 31 genera, 40 species and 21 families with 3.091 ind.m² distributed in the three areas. The areas II and III presented larger wealth and diversity, expresses so much for the number of families as of identified species. The families, Convolvulaceae, Euphorbiaceae and Fabaceae presented larger number of species in the open and closed plots. Aristida adscensionis, (area I and II) and Cyperus uncinulatus (area III) the species that presented were larger value of importance in the closed and open plots were.

The objective of this work was to evaluate the influence of crescents phosphorus levels in two hybrids of forage sorghum cultivated on "Zona da Mata" region, State of Alagoas. The treatments were two hybrids of forage sorghum: BRS304 e BRS310, and four phosphorus levels: 0, 25, 50 e 75 kg ha-1. The statistical design was the complete randomized block with four replications in a split plot scheme. Each experimental plot was constuited for five row of 4.5 m, spaced of 0.70 m. The soil of experimental area received lime to increase basis saturation to 60%. During the sowing, all experimental area received 100 and 120 kg ha-1 of N and K, respectively. The plants were collected 40, 50, 60 e 70 days after emergence. The mass collected was separaeted in leaves photosynthetic active and remaining of the plant. When the grains were on the "farináceo duro" stage, the yield was evaluated in 1.4 m2 on plots center. The phosphoted fertilization increases linearly the sorghum production until 75 kg ha-1 level of P. The phosphorus provides better grain participation on total dry matter of sorghum plants.

Seeds of Caesalpinea ferrea Mart. ex Tu. var. leiostachya Benth. present low and irregular germination due to dormancy caused by the impermeability of the tegument. With the purpose to determine an efficient method to accelerate and uniformize seed germination, they were submitted to different immersion periods (0, 5, 10, 15, 20, 25 and 30 minutes) in sulfuric acid (95-98%), influence emergency and vigor (first count, speed index, medium time and relative frequency of emergency, length and dry matter of the seedlings). The experiment was carried out under greenhouse conditions with an experimental design of completely randomized, with seven treatments and four replications. The pre-conditioning of the seeds with immersion in concentrated sulfuric acid was efficient to overcoming seed dormancy, by increasing the percentage and speed emergency, the first count of emergency, length and dry matter of seedlings and reduction in the medium time for emergency. The efficiency of this chemical treatment with concentrated sulfuric depends on the immersion time, and 10 to 20 minutes were the most adequate to provide larger emergency uniformity percentages and vigor.

Zizyphus joazeiro tree is a typical semi-arid region of northeastern Brazil, is mainly in the areas of crystalline basement in lower parts, where soils are deeper. It is endemic to biome caatinga, has great economic potential and importance to the semi-arid region, both in terms of socio-environmental, adds several species of bees, insects and birds, and for animal feed as fodder. The objective was to evaluate the possible effects of water stress and salt in the germination of seeds of Zizyphus joazeiro. The number of seeds in 100 per treatment, 04 repetitions of 25 seeds were placed to germinate on filter paper soaked with different solutions of NaCl and PEG 6000 (2.5 share the weight of paper: 1.0 solution or water) in potential 0.0 (control distilled water); -0.3, -0.6; and -0.9 MPa. Then were placed in the germination chamber at a temperature of 30 ºC in the presence of light. The results led to the conclusion that salt stress provides further reduction in the germination and speed of germination of Zizyphus joazeiro seeds than the water stress, regardless of the substance used for stress induction, germination limit was 0.6 to -0.9 MPa.

The objective of this study was to evaluate the accumulation of matter, dry matter content of Brix and two varieties of sugar cane, influenced by the phosphorus cultivated on "Zona da Mata" region, State of Alagoas. The experiment, a factorial 2 x 6, was composed of two varieties of cane; RB867515 and RB92579 and six phosphorus levels: zero, 30, 60, 90, 120 and 150 kg ha-1, with the source of the phosphorus triple superphosphate . Was also used nitrogen and potassium in doses equivalent to 100 and 200 kg ha-1 and K, respectively. The soil of the experimental area was set to raise the base saturation to 60%. At the beginning of the first rainfall of the rainy season of 2006 was performed with micro fertilization in coverage, in doses equivalent to 6,0; 6,0 and 7,0 kg ha-1 of Cu, Zn and Mn, respectively. Was The chemical control of weeds. Every month, from August to October 2006, samples were collected in the cane plant. There was initially the number of plants m2, followed by weighing the material. It was subsequently withdrawn a subsample containing ten plants for weighing. After weighing the material was passed in horsemanship and homogenized, again drew up a sample of approximately 300g, leading them to forced ventilation oven at 65 ºC, to obtain constant weight. Resulting in the production of natural (MN) and dry matter (DM). In July, we analyzed the levels of Brix% juice in the refractometer Brix. The average values of production of natural (MN), dry matter (DM) and contents of Brix% were subjected to analysis of variance and regression for variables. The accumulation of dry matter and were influenced by fertilization. The contents of Brix% in two varieties did not suffer significant influence of fertilization.

An experiment was carried out at a greenhouse of Plant Science Department of the Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró-RN, in the period of May to June of 2008, with the evaluate the agronomic performance of rocket in function of their times of decomposition of Ipomoea asarifolia incorporated. A completely randomized desing with six treatments and four replications. The treatments consist of: T1 (45 days incorporated); T2 (30 days incorporated); T3 (15 days incorporated); T4 (0 days incorporated); T5 (336g vaso-1bovine manure); T6 (Control no fertilized soil). The rocket cultivar grown was cv. Cultivada. The evaluated traits were: plant height, number of leaves per pot, dry mass and yield of grains. All the times traits were significantly affected by the amounts of Ipomoea asarifolia incorporated. Height mean value for plant height, dry mass and yield of grains were obtained in the time 11,8 days incorporated of 18,3 days for number of leaves.

The ground pods of mesquite (GPM) was submitted to different thermal treatments for two hours after wanted temperature stabilization, for making of the treatments: A = ground pods of mesquite without heat treatment (approximately 30ºC); B = The ground pods of mesquite treated at 60ºC; C = The ground pods of mesquite treated at 80ºC; D = The ground pods of mesquite treated at 100ºC and E = The ground pods of mesquite treated at 120ºC. Soon after, samples were collected for accomplishment for chemical analyses and in vitro digestibility. A completely randomized design with three replications was utilized. The DM, CP, NFE, CF, ADF, celluloses, lignin, ash and CE values, did not were affected (P>0.05) by temperature. It was observed a quadratic effect (P<0.01) on the contents of EE, decreasing linear effect (P<0.01) on the CC and increasing linear effect on the NDF (P<0.01) and Hemicellulose (P<0.05) contents. The in vitro dry matter digestibility and the in vitro organic matter digestibility were not affected (P>0.05) by temperature. On the other hand the in vitro protein digestibility level, showed a quadratic effect (P<0.05), decreasing after 54ºC.

In sight of scarcity of references and information on the atemóia, this work considered to evaluate some chemical and physical analyses in intention to characterize two maturation stages. The used fruits in the experiment had been gotten in the Agropólo Mossoró-Assú, in the state of the Great River of the North. For this, the following analyses had been carried through: length and diameter of the fruit, total firmness of the pulp, soluble solids, pH, titulável total acidity and vitamin level C total. Differences between stadiums of maturation with degradation of the cellular components and the reserves of the fruits had been observed, thus reducing the firmness of the pulp and liberating simple sugars, respectively. It occurred increment in the acidity and consequence decrease in the value of pH. The vitamin C level didn't suffer significant alterations between such stages.

The castor bean is a demanding culture in fertility of the soil, especially of phosphorus, that is one of the nutrients more limitation the agricultural production. This experiment was carried with the objective of evaluating the answer of the castor bean during her initial development to different phosphorus doses. The used design was it entirely randomized, with five treatments and three repetitions, where the treatments consisted of different phosphorus doses (0, 3, 6, 9, 13 e 15 g planta-1). The plants were collected at 65 days after sowing for evaluation. The evaluated characteristics were: the number of leaves, leaf area, height, stem diameter, matter dries of the aerial part, of the system roots and total. The castor bean showed response to phosphate fertilizer in all characteristics evaluated, presenting consider increasing the parameters of growth. The best results were found with a dose of 9 g planta-1 P.