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.

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.

Diazotrophic bacteria play important role on economy nitrogen fertilizer in forage glasses and environmental sustainability. With the objective of evaluate the occurrence of diazotrophic bacteria associated associated with native forage at two different times and identify isolates with potential for fixing N2 in the semiarid region. Was conducted in the Soil Laboratory of the Centro de Saúde e Tecnologia Rural in Federal University of Campina Grande, Campus de Patos, Paraíba. A study was carried out at the Soil Laboratory of the Centro de Saúde e Tecnologia Rural of the Federal University of Campina Grande, in Patos, Paraíba. The objective this study was to verify in the native diazotrophic endophytic bacteria associated with forage glasses and to identify isolates in NBF hability, during the rainy and dry seasons in semiarid region. Root samples of three forage grasses [Andropogon gayanus Kunth (Andropogon), Panicum maximum Jacq. cv. Tanzania (Tanzânia) and Cenchrus ciliaris L. (Buffel)] cultivated in the field experiment was utilized. The bacteria were isolated in NFb culture media free-N specific for Azospirillum spp., the isolates was quantified, phenotypically characterized, purified. From caracterized after, was evaluated for their nitrogenase activity in vitro. The resultas show diazotrophics bacteria growth in the three forage grasses tested. The ocorrency diazotrophics bacteria be influencied by genotipic plant and seasonal variation. A more density of NSDB of the genus Azospirillum associated in the root grasses were obtained in dry season. The NSDB isolates, show a high potencial for new studies on the genetic caracteristcs and avaliation the inoculo potential to (BNF) associated on grasses in semiarid region.

The correct management of an irrigation system depends on reliable estimate of reference evapotranspiration (ETo). This paper aimed to evaluate the performance of some empirical equations used to estimate ETo under the climatic conditions of the municipalities of Anagé, Piatã and Ilhéus, located in the Southwest of Bahia State, Brazil. Climatic variables were used for the years 2006 and 2007 obtained through the automatic data collection platform of the Superintendence of Bahia Water Resources / National Institute for Space Research, in which he averaged variables for the two years. To compare the ETo values estimated by methodos of Penman Modificado FAO 24, Radiação, Blaney-Criddlle, Hargreves-Samani, Priestley-Taylor and Turc with the standard method Penman-Monteith (FAO 56) was performed by parameters of regression equation (b), determination coefficient (r²), correlation coefficient (r) estimated standard error (EEP), agreement index (d), index of confidence or performance (c) in daily, three, five and seven days scales. The best methods to estimate ETo for the climatic conditions of the three sites, depending on the indices and parameters studied were by the order: Blaney-Criddle, Penman Modified - FAO 24, FAO 24 Radiation, Turc, Priestly- Taylor and Hargreaves-Samani.

The aim of the present paper was to evaluate the Jathropa curcas L response to different doses of nitrogen, water regimes and soil surface nature. The experiment was conducted from May 2009 to February 2010 under greenhouse conditions at the Sustainable Development Center of the Federal University of Paraiba in Sumé-PB. A factorial experiment in blocks was used with four organic fertilizer (0, 50, 100 and 150 kg of N/ ha), four irrigation levels (50, 75, 100 and 125% the Class A pan evaporation) and four additional treatments with soil mulching. Sixty plastic vases 100 l capacity were used to cultivate the plants during 257 days and a Class A Evaporation Pan was installed in the greenhouse to monitor daily water evaporation. The plant variables evaluated were plant height, stem diameter, leaf area, total aerial and root dry mass. The increase of the soil water content and soil mulching had significant effect on the evaluated plant variables.

The aim was to evaluate the selectivity of insecticides used to control the fall armyworm to epigeic occurring on the soil of a crop of millet. The research was conducted in field in the town of Dourados. The experiment consists of randomized blocks with eight treatments and four replications. Sampling of natural enemies in observable by traps "pitfall modified." The Belt 480 SC insecticide, was not selective family Tachinidae, but was slightly toxic to Formicidae and selective Araneidae and Calossoma granulatum. The insecticide Gallaxy 100 CE, the mortality rate obtained with 63% in the first (DAA) for Araneidae and Tachinidae families, and was selective to a DAA for C. granulatum predator. The insecticide Tracer 480 SC, was not selective to the spiders, Formicidae and Tachinidae. The insecticide Match 50 EC was the most toxic C. granulatum predator and the Spiders in the assessment a DAA, which obtained a mortality rate of 100% and 67% respectively. The effect of the insecticide Karate SC 250, had a mortality rate of families Araneidae and Formicidae, 89 and 60% mortality. The Lannate 215 S to a DAA, its mortality rate for C. granulatum and families Araneidae, Formicidae and Tachinidae 100, 78, 60 and 50%, and selectivity to Tachinidae. The insecticide Talstar 100 EC, was toxic to the Family Formicidae, Araneidae and Tachinidae in the assessment a DAA, which obtained a mortality rate of 80%, 78% and 75% and preserved population of C. granulatum predator.

This paper had as objective to build and to calibrate weight lysimeters of low capacity and to establish comparisons between the working status of constant level water table lysimeters. Two weight lysimeters of 15-L and 50-L and two constant level water table lysimeters of 15-L and 50-L were built at Embrapa Mandioca & Fruticultura Irrigation and Fertirrigation Laboratory, Cruz das Almas - BA, Brazil. Linearity, repetitivity and hysteresis errors in the range of reading of the weight lysimeter. Simultaneously measurements of soil evaporation were performed on bare soil with the two lysimeters in a 1-h interval. Afterwards, orange transpiration was measured by using lysimeters and by using a heat balance sap flow equipment. Results showed that the relation between analogical signals and the standard mass in the lysimeter provided linear equation with reasonable goodness of fit. The systematic and random errors were larger in the lysimeters of larger capacity. The instruments were able to make readings with good stability during the days of measurements and were also able to detect mass variation due to hourly transpiration. However, the measurements were in agreement if comparing average three day data.

The aerial application of pesticides is a valuable tool in agriculture, when based on well-defined technical criterion. This paper aimed to evaluate the spatial dependence of the drops spectrum and its deposition by an aerial application over the soybean crop (Glycine max). An experimental agricultural aircraft was used, model Acrobat, from England Company, equipped with eight rotary atomizers, model Micronair AU 5000, applying a spray volume of 20 L ha-1. To obtain the droplet spectrum were used hidro sensitive targets consisting of paper, distributed in the middle third and higher plants. Spectrum analysis of the drops was made using the computer program "CIR" version 1.5 in 2002. To determine the amount deposited on the leaves of the upper, middle, and bottom of the soybean plants, we used the bright blue food coloring added to the spray solution. These leaves were washed and the amount determined by spectrophotometry. The analysis of spatial dependence was evaluated using the GS + version 7 program. The results show no spatial dependence for the attributes. There was a low percentage of coverage in the upper and middle third of the plants. The geostatistical analysis can be used to characterize the spatial attributes of application coverage, but should be used a sampling grid of smaller size.

The development of soybean cultivars adapted to different regions and generation technologies contribute to Brazil to increase its production, placing it as the second largest world producer and exporter of grain. Several factors have limited its production among these diseases, approximately 40 already identified in Brazil, especially powdery mildew (Erysiphe diffusa U. Braun & S. Takami), one of the most important, resulting in reductions of up to 40% in income susceptible cultivars. The study aimed to evaluate the severity of powdery mildew on soybean genotypes during seven seasons of evaluation, by analyzing disease progress, using regression. It was developed at the Federal University of Viçosa, Minas Gerais arranged in split plots inrandomized block design seven evaluations were performed by visual quantification of the level of infection of leaf area infected (NIAFI). Regression analysis was performed to check the progress of thedisease. The results showed that the method is efficient for such studies, showing clearly the evolution of the disease, and aiding in the discrimination of resistant and susceptible genotypes at the third assessment. Stood out as sources of resistance genotypes UFV-16, UFV-19, UFV 89-361826T2, FT-Abyara RC5 (F4), FT-RC6 Abyara (F2), FT-10 RC5 (F3), Doko RC, UFV UFV 95-4121333 and UFV 94-334268. FT-104 and FT-Crystalina stood out as susceptible and BR-16 and FT-Estrela as highly susceptible, while the other showed intermediate behavior.

The aim of this paper was to evaluate the no-preference for feeding and biological aspects of Spodoptera eridania fed on cowpea cultivars BR17 Gurgueia, BRS Urubuquara, BRS Nova Era, Sempre Verde, BRS Milênio and BR3 Tracuateua. In free-choice test, leaf discs were placed in Petri dishes where one third instar larvae per cultivar was released, whereas in no-choice test one leaf disc was placed per Petri dish where one caterpillar per cultivar was released, evaluating their attractiveness after 1, 3, 5, 10, 15, 30, 60, 120, 360 and 720 minutes, as well as the leaf area consumed. Randomized blocks and complete randomized blocks design were used for free-choice and no-choice tests, respectively, with six treatments and 10 replications. The evaluation of the biological parameters of S. eridania was carried out in Petri dishes where recently hatched caterpillars were transferred in the proportion of one per dish, and the leafs of the cultivars were offered to them during the whole larval period, and we evaluated: periods and viabilities of larvae and pupae, overall viability, weight of larvae and pupae, sex ratio, longevity and overall cycle. Complete randomized design was used with six treatments and 30 replications. In no- preference for feeding free-choice test the cultivars Sempre Verde and BR17 Gurgueia were the most and the least consumed, respectively. Regarding the effects of cowpea cultivars on larval viability we can infer that BRS Urubuquara and Sempre Verde show antibiosis-type resistance to S. eridania.