The objective of this work was to obtain informatio n about the best sources and doses of nitro- gen and potassium fertilizers for obtaining vigorou s rootstocks umbuzeiro in Northeastern Brazil. In s eparate experiments, we tested two sources of nitrogen, ure a and ammonium sulfate and five N rates (0, 350, 70 0, 1400 and 2800) mg.dm -3 , and two sources of potash fertilizer (potassium c hloride and potassium sulfate) in five doses of K20 (0, 1.800, 3.600, 5.400 and 7.200) mg. dm -3 substrate. The experimental design was in random- ized blocks in factorial 2 (sources) x 4 (doses), w ith ten treatments and four replications and ten pl ants per plot. Parameters were evaluated for the growth of seedlin gs. Doses of nitrogen and potassium applied to soi l had a negative influence in the survival of seedlings, shoot length, stem diameter and root fresh weight of seedlings.

This study had the objective to evaluate the action of aqueous (EAC), ethanolic (EEC) and decoction (EDC) extracts of juremapreta bark Mimosa tenuifloraand aqueousroot extract (EAR) on the control of alternaria black spot on watermelon, as well as evaluating the mode of action of these extracts, either by presenting toxicity to the pathogen and the ability to alter the metabolism of the host by activating protective enzymes. M.tenuiflora extracts were tested for inhibition of germination, mycelial growth and sporulation of A.cucumerina in vitro. Under controlled conditions (in vivo), the plants were sprayed with the four extracts in three concentrations (05, 4.0 and 10 mg.mL-1) 48 hours before inoculation. The evaluations were based on disease severity and determination of enzymatic activity. In the field the four extracts were sprayed at two concentrations (4.0 and 10 mg.mL-1), evaluating the severity of the disease with the help of descriptive scale. The EAC inhibited 100% germination, mycelial growth and sporulation of A.cucumerina in vitro. The EAC induced synthesis of β-1,3 glucanase and peroxidase, reducing 97% of the disease, in a controlled environment and 31% in the field, being superior to the other extracts and commercial fungicides: copper oxychloride which controlled 79% and 21% for environmental controlled and field respectively, and tebuconazole + trifloxystrobin which controlled 15% in the field. These extracts showed potential to control alternaria leaf spot is caused toxicity to the pathogen or by inducing resistance.

Cowpea [Vigna unguiculata (L) Walp] have great social and economic importance for the Para State. It grows well in areas with low precipitation and two crop cycles can be obtained annually. This study aimed to assess the effect of the residual fertilization from a previous culture (Sorghum bicolor L. Moench) and crop systems on cowpea yield and macronutrient concentration on leaves of three cowpea cultivars (BRS- Milênio, BRS-Urubuquara e BRS-Guariba). The study was conducted at the UFRA. The treatments were two crop systems (minimum tillage and conventional), four levels of potassium (50, 100, 200 e 300 kg de KCl ha-1 applied to a previous sorghum culture) and the three cowpea cultivars. Treatments were organized as a three (4 x 2 x 3) factor experiment on a randomized complete block design. The soil was a yellow latosol. In each ex- periment plot five plants were selected to determine shoot dry matter and foliar nutrient concentration. Grain yield was determined after harvesting all plants on the experiment plot. The residual KCl fertilization affected foliar nutrient content, but did not affect shoot dry mass or yield of grain. Yield was higher in the minimum tillage system. Highest yield (1590 kg ha-1) was recorded int the cv. ‘Guariba’ when 100 kg of KCl ha-1 had been used in the previous crop. The highest content of leaf N and K was found in cowpea under minimum till- age system. The amount of P and Mg were higher in the conventional system whereas the amount of Ca did not change.

The evaluation of profitability of ‘Ponkan’ mandarin subjected to chemical thinning may constitute important information that allows the farmer to evaluate the feasibility of adopting the practice of management in his orchard. Thus, this study was developed with the aim to evaluate the profitability of the practice of chemical thinning in ‘Ponkan’ mandarin trees (Citrus reticulata Blanco). The work was carried out in 2009, 2010 and 2011 in an unirrigated orchard of ‘Ponkan’ mandarin, in the city of Perdões, the southern region of Minas Gerais, Brazil. Before the treatments, in October 2008, 80 plants we selected with abundant flowering on the entire canopy, so that all the mandarin trees could have production significant quantities of fruit. In half of the plants was not performed the chemical thinning and the other half was applied 600 mg L-1 of Ethephon, after the period of physiological fruit drop, in January 2009, January 2010 and January 2011, when these were at stage 25 to 30 mm in transverse diameter. At harvest, in June 2009, June 2010 and June 2011 were evaluated the production per plant (boxes of 22 kg) and estimated the productivity of plants subjected to the chemical thinning and plants that were not subjected to this practice. The profitability analysis was performed in a simplified manner considering the production costs of the orchard already deployed with the production stable. The practice of chemical thinning promoted superiority of 176% on the average profitability of 'Ponkan' mandarin trees.

The replacement of the natural systems by sugar cane leads to fundamental alterations in soil carbon and nitrogen stocks and consequently in the global cycle of these elements. This study was conducted in the municipality of Capim, Paraiba State, and the objective was to evaluate carbon and nitrogen stocks in soils of a natural forest in comparison to sugar cane with and without vinasse. The studied soil was a Dystrophic Gray Argisol. The soil samplings were performed in five replicates (five profiles) at the depths of 0-5, 5-10, 10- 20 e 20-40 cm. The systems were selected namely, native forest; sugar cane with vinasse and cane sugar with- out vinasse. The carbon and nitrogen contents and stocks decrease after the change of native forest to plant sugar cane. In general, there is not significant difference in the carbon and nitrogen contents and stocks be- tween the environments of cane sugar. The systems of cane sugar with and without vinasse are functioning as C -CO2 emitter when compared with the native forest.

The main goal aim of this work was study the parameters that influence in the spatial variation of the chlorophyll "a" in the surface water of the Orós reservoir, Ceará state, Brazil. It was studied the compari- son of the water in that reservoir, too. Twelve water samples were taken in seven different sites in the reservoir. They were sampled every two months from April/2008 to April/2010. Total phosphorus, water temperature, water transparency and the chlorophyll "a" production were analyzed. To assessment the eutrophication be- tween the sampled sites it was used the Hierarchical Cluster Analysis. Results showed that the eutrophicationallowed observes that the water temperature, water transparence and total phosphorus are influential in the chlorophyll "a" production. The increasing of the water temperature increase the chlorophyll "a" concentration. Hierarchical Cluster Analysis showed that the sampled sites 1 and 2 are similar in relation to water eutrophication and it separates the water in two different groups. The group 1 was formed because of the both high sedi- ment concentration and the low levels of chlorophyll “a” and the group 2 was formed because of the both highwater temperature values and high chlorophyll "a" concentration.

The crop demand by nitrogen varies from one crop to other as well as the amount and applica- tion time, and this nutrient can be lost by leachin g, volatilization and erosion. The objective of thi s study was to evaluate doses, sources and times of nitrogen appli cation in rice of high lands cropped in no till sys tem. The work was conducted in Selvíria, State of Mato Gross o do Sul, Brazil, in a soil originally under Cerrad o vegeta- tion. A randomized blocks design, with the treatmen ts disposed in a factorial scheme 5x3x2 was used. T he treatments were constituted by five nitrogen doses (0, 50, 100, 150 and 200 kg ha -1 ), three nitrogen sources (urea; ammonium sulfonitrate plus nitrification inh itor and ammonium sulfate) and two application time s (at sowing or at flower bud differentiation), with four repetitions. The sources of nitrogen, as well as t he applica- tion times had similar effects for most of evaluati ons. The N doses influenced linearly or with quadra tic adjust- ment the plant height, N leaf content and grains yi eld, in the two growing seasons. The chlorophyll co ntent and the number of ears m -2 were affected only, in the first year. The highest yield in the growing season of 2007/08 was obtained with the dose of 149 kg ha -1 of N. In 2008/09 growing season the increase of N doses provided increment in the grains rice yield, until the maxim um dose evaluated (200 kg ha -1 of N).

Some techniques can be used in order to promote the recovery of degraded areas like riverine ecosystems, and those with low impacts present a fast regeneration, through an ecological succession with no need for human intervention. It is necessary to study the use of techniques that contribute to the recovery of these ecosystems, such as soil bioengineering, which involves the use of biologically active elements working on soil stabilization, combined with inert elements such as concrete, wood, polymers, and geotextiles made with synthetic material or plant fibers. This work was carried out in order to evaluate planted species develop- ment and endemic species in the ecological succession, along the Paramopama river margin, located at the mu- nicipality of São Cristóvão, in Sergipe State, submitted to soil bioengineering techniques. Two types of geotex- tiles (Fibrax and Syntemax and 400 TF) arranged in two blocks and three treatments were tested, and the be- havior of the vegetation and efficiency of geotextiles were observed for a period of 11 months monitored by the floristic survey. The abundance of the species Crotalaria spectabilis and Calopogonium muconoides was stud- ied, and subsequently classified according to vegetation succession stage. The study revealed that the use of geotextile Syntemax 400 TF on the left bank promoted the greatest abundance of species, resulting in a greater vegetation cover, and consequently better protection of the slope. The geotextile Syntemax 400 TF was the most appropriate among the tested types, to promote the floristic recovery in the studied area and probably in those with similar soil-climatic conditions.

The crisphead lettuce is a greenery adapted to grow in regions with mild temperatures and lack of rain. The objective of this work was to evaluate the performance of crispheadlettuce cultivars (Del ícia, Teresa, Lucy Brown, Raider Plus, Mauren, Angelin), under tropical climate in city Cáceres-MT, in two h arvest times.The experiment followed the randomized comple te block , with four replications, were arranged in 6 x 2 factorial, being, six cultivars in the crisphead le ttuce and two harvest time. Was evaluated the total and com- mercial production, commercial dry matter mass, com pactness, plant diameter, “head” diameter, health a nd was estimated the proportion of stem in the “head”. The cultivars Teresa and Delícia exhibit the total pro duction upper in relationship the other cultivars evaluated in the experiment, with productions of 631.1 and 5 89.3 g plant -1 , respectively. The second harvest, at large, has w as upper in relationship first, with 607 g plant -1 . The cultivar Teresa, in the second harvest, exhibit the upper result from the commercial production with 4 79.6 and 483.6 g plant -1 , in the first and second harvest, respectively. Th e cultivar Teresa, in the second harvest, exhibit the upper evaluate from compactness. The cultivars Teresa and Delícia were the most suitable for culti vation from weather of Cáceres - MT, and the harvested mus t be performed at 67 days after sowing.

This work was carried out with the objective to study the foam-mat drying of Cereusjamacaru pulp fruit with albumen (2%) and “Super Liga Neutra” (2%) with whipping time of 5 min, dried inoven with air circulation at 70; 80, and 90 °C with three different foam thicknesses (0.5; 1.0 and 1.5 cm). The drying curves were fitted with the Page, Henderson and Pabis and Cavalcanti Mata models. Drying time was influenced by the foam thickness and process temperature being the process faster for smaller thickness and higher temperature. The Cavalcanti Mata model presented the best fit of the experimental foam drying kinetics data.