The management when done so improperly can cause changes in the physical, chemical and biological soil properties. The aim of this study was to evaluate the behavior of physical attributes in a dystrophic Oxisol under different vegetation covers and managements in the city of Chain southern state of Piauí. The experimental design was randomized using a split-plot with four types of cropping systems and four sampling depths, with three replications. Cropping systems were studied: Nim (Azadirachta indica), elephant grass (Pennisetum purpureum), Brachiaria decumbens and Native Forest sampling depths 0-0.10, 0.10-0.20, 0.20-0, 30 and 0.30-0.40 m. The effects of hedges and management on soil physical properties in different soil depths were recorded from the analysis of variance and treatment means compared by Tukey p <0.05. Determinations were carried out density, macroporosity, microporosity, total porosity, and resistance to penetration in all cropping systems. The elephant grass and native forest had the lowest values of penetration resistance and bulk density, higher values of total porosity and macroporosity, reflecting better physical condition of the soil. The area with Nim and Brachiaria was influenced by animal trampling, thus causing increase of soil density and hence the resistance to penetration.

Drip irrigation is one of the most efficient method s forapplyingwaterto a crop, capable of deliv- ering water at a rate close to the demand. Many eff orts have been required to estimate the amount of w ater needed by plants. Therefore studying soil water ext raction by plants linked to mathematical modeling f or be- havior prediction, and linked to computational reso urces to allow complex mathematical procedures to b e real- ized in a short space of time, becomes a powerful a nd necessary alternative for the understanding and quantifi- cation of the involved processes. Simulations were performed through a computational model, with the purpose of estimating the crop coefficient (K c ) of watermelon in the region of Mossoró-RN, using a three-dimensional macroscopic root water uptake model, which solves t he sink term of the Richards equation. The simulati ons results were compared with an experiment that estim ated the K c using lysimeter. The results of Kc estimated by the model showed a good agreement with lysimeter re sults in all chosen statistical indexes, indicating that the model can serve as a tool for predicting transpirat ion and evaporation of soil water under certain con ditions, and as a tool to aid the irrigation management.

The Ceara State has a variety of species of non-traditional fruits that are consumed in natura and/or processed by local population, with economic potential for agro-industrial processing, however, still poorly studied. In this context, the aim of this research was to evaluate the genetic variability of puçazeiro ‘Coroa de Frade’, native tree from coastal vegetation of Beberibe, Ceará, Brazil, by physico-chemical and chemical characteristics of their fruits. Fifteen genotypes were evaluated. The traits analyzed were: soluble solids (SS), titrable acidity (TA) (% of citric acid), pH, SS/TA ratio, total sugars, reducing sugars, starch and, total and soluble pectin. The genotypes were characterized as a good alternative to the market of exotic fruits, showing high values of SS (20,40 a 31,00 °Brix) and low mean values of titrable acidity (0,27 a 0,58 % of citric acid), producing SS/TA ratio ranged between 37,5 and 102,43, with emphasis on the genotype '8', which pre- sented SS/TA ratio of 95.05. The genotypes showed fruit netting with high starch (> 1%). The values of total pectin (0.35 to 0.98%) and soluble pectin (0.13 to 0.74%) reinforcing the use of this fruits in the industry, with low cost to manufacture of candy and jellies. The repeatability analysis showed that most of the observed varia- tion among genotypes is associated with the genetic component. Therefore, it can be concluded that the studied genotypes of puçazeiro 'Coroa de Frade' showed wide genetic variability and have fruits indicated even for fresh consumption as well as for processing.

This study evaluated the effect of different salt concentrations on growth, synthesis of organic solutes and ionic balance (Na+, Cl- and K+) of Jatropha curcas L. for 28 days. Seven treatments were established: 0, 15, 30, 45, 60, 75 and 90 mol m-3 NaCl in a completely randomized design with five replicates per treatment. The largest concentrations of NaCl the addition of the salt was made gradually to avoid osmotic shock. The number of leaves and leaf area were reduced in plants subjected to salinity from 30 to 45 mol m-3 NaCl, respectively. The production of fresh and dry matter were reduced from 60 mol.m-3 NaCl up to 36%. The concentration of soluble carbohydrates and total soluble proteins increased significantly only in plants exposed to 15 and 30 mol.m-3 and 30 mol.m-3 NaCl, respectively. The total phenol content increased in plants subjected to salinity from 30 mol.m-3 NaCl. The increase in the levels of total phenols, soluble carbohydrates and soluble proteins and the absence of reduced growth in seedlings subjected to 30 mol.m-3 NaCl indicates the activation of an efficient mechanisms of acclimatization of this stress magnitude. The levels of Na+ and Cl- increased in all parts of the plant were increased concentrations of salt in the nutrient solution. The high levels of Na+ and Cl- indicate the absence of extrusion mechanisms of these ions.

In order to quantify the growth, accumulation and exportation of macronutrients by carrot ‘Forto', and obtain equations that best represent them, it was conducted an experiment in the São Gotardo (MG), from May to September 2004. Samples were taken at 40, 50, 60, 70, 80, 90, 100, 110 and 120 days after sowing (DAS) to determine dry matter and accumulation of macronutrients in leaves and roots. At 40 DAS, five days after thinning, the plants had 0.18 g and 0.04 g in dry leaves (LDM) and of roots (RDM), respectively. From then, until 88 DAS, the partitioning of photoassimilates and accumulation of matter in the shoots were more pronounced. The RDM was low until 80 DAS, which corresponded to two thirds of the crop cycle, from when the amount of material allocated in this part of the plant had strong growth, surpassing, at 88 DAS, the amount of LDM. The nutrient accumulation was small in the first 60 DAS, coinciding with the period of lower dry matter accumulation. The order of decreasing macronutrient accumulation by the crop were: K > N > Ca > P > S > Mg, in the amounts of 906.7, 438, 155.46, 87.4, 58 and 37.63 mg plant-1, respectively. The root participated with 60.5% of the accumulation of N, 86.1% of P, 58% of K, 25.5% of Ca, 55.6% of Mg and 65.5% of S. Considering a population of 590,000 plants per hectare, the total quantity of nutrients by the crop of carrots was 258.3, 51.6, 534.8, 91.7, 22.2 and 34.2 kg N ha-1, P, K, Ca, Mg and S, respectively.

Ni was the last nutrient characterized like essenti al for plants. Its essentiality is due to participa - tion as constituent of urease enzyme, which makes i t extremely important for the metabolism of N. Thus , the objective of this study was to investigate the grow th, content and accumulation of urea and nutrients in cowpea bean plants ( Vigna unguiculata (L.) Walp.) ‘IPA 206’ according to nickel rate and two soil types. The experi- ment was carried out in a greenhouse at Universidad e Estadual do Norte Fluminense Darcy Ribeiro, using a 5 x 2 factorial scheme in a randomized block design wit h four replications. Treatments consisted of foliar applica- tions of five nickel concentrations (0, 20, 40, 60 and 100 mg L -1 Ni) in the form of NiCl 2 .6H 2 O and two soils, a Typic Quartzipsamment and a Tb dystrophic Red-Yello w Ultisol. Ni rates promoted Ni toxicity symptoms j ust on young leaves of bean. These symptoms were charac terized by small reddish spots that have not progre ssed during the time and did not influence on the plants development. The foliar application of Ni increase d levels of this micronutrient in stems, mature leaves, youn g leaves and pods of cowpea bean, indicating high m obility of this micronutrient in the plant, but did not alt er the urea contents, indicating no effect on the a ctivity of urease enzyme. The dry mass of the shoots and the c ontent of others nutrients were not affected by fol iar appli- cation of Ni. Plants grown in Ultisol showed higher growth and higher content of urea and Cu in mature leaves; K and B in mature leaves, young leaves and twigs an d Zn in mature leaves and stem.

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).

This research aimed to evaluate the tannins extracted content of Anadenanthera colubrina (Vell.) Brenan var. cebil (Gris..) Alts. bark in aqueous solution of sodium hydroxide, sodium sulfite and hydroxide + sulfite having as comparison the amount extracted in distilled. A total of 25 g of dry sawdust and 3% of chemicals were used with relationship to dry weight of sawdust. To compare the effect of water with one of the other used solutions it was found that the addition of sodium hydroxide, sodium sulfite or hydroxide + sulfite caused an increase in solid total contents (TST) of 60,17%, 28,45% and 60,17%, in condensed tannin contents (TTC) of 34,5%, 20,02% and 18,02% and of no-tannins of 117,34%, 47,3% and 146,6% and a reduction in the Stiasny’s index of 15,62%, 5,53% and 24,51%, respectively. Statistical analyzes showed that the sodium hydroxide solution extracted a larger amount from tannic substances when compared with the water, having the sodium sulfite and the hydroxide + sodium sulfite solutions presented middlemen results. The distilled water extracted a lower solid total content than other solutions, but the extract contained a greater Stiasny’s index than those obtained by other solutions.

This work aimed to evaluate the effect of mechanical injuries caused by impact, abrasion and cut in guavas cv. 'Paluma' under fruit quality during cold storage at 10°C, and at environment temperature. Was to adopt the completely randomized design in a split-plot in time considering as plots, the mechanical injuries and subplots, the storage periods (0, 5, 8, 11, 14 and 17 days) with four replicates of two fruits per experimental unit. The mechanical injuries were induced considering the following criteria: T1, witness, without fruit visible damage; T2, fruits impacts, two impacts per fruit at a height of 85 cm; T3, fruits subjected two cuts, on opposite sides, depth of 2 mm and length 30 mm; T4, fruits subjected to abrasion, area of 10 cm2. Was evaluated the exterior color, the external appearance, the internal appearance, the severity of disease. Injury due to impact, abrasion and cut no influence on in exterior color, external appearance, internal appearance and severity of diseases of guava cv. 'Paluma' during storage for 11 days at 10oC. But, the quality was impaired by mechanical injuries six days after exposure to 30°C.

The cowpea is a plant of great importance for small producers of the Brazilian Northeast, in particular the region of the Vale of Pajeú. The destination of this plant for the production of green beans constitutes an important source of income for family farmers and presents itself as a good alternative for industrial processing. The objective of this study was to evaluate the potential of cultivars of the cowpea for production of green beans in the conditions of Serra Talhada - PE. The experiment was conducted on the campus of Uni- versity Federal Rural of Pernambuco (UFRPE) / Academic Unit of Serra Talhada (UAST) in the period from August to November 2011. We used five developed improved cultivars: BRS-Tucumaque, BRS-Caumé, BRS- Itaim, BRS-Guariba and BRS-Potengi, and three local cultivars: Corujinha, Paulistinha and Sempre-verde. The experimental design was randomized blocks with four replications, where each cultivar was considered a treatment. The characteristics evaluated were: number of days to beginning of flowering (NDIF), plant size (PP), days to maturity of green pods (DMVV), period of production of green pods (PPVV), length of green pods (CVV) number of grains of green pods (NGVV), grain weight of green pods (PGVV), yield of green pods (PRO.VV), productivity of green grains (PRO.GV), index of green grains (IGV). Cultivars BRS-Potengi, BRS- Tucumaque, BRS-Guariba, BRS-Itaim, BRS-Caumé and Paulistinha and showed potential for the production of green beans in Serra Talhada-PE, under irrigated condition.