This study aimed at assessing the influence of different seasons of the year (dry and rainy) on urea nitrogen (MUN) concentration of buffalo milk in a commercial herd from Rio Grande do Norte state. The region is characterized by a rainy tropical climate with a dry and wet season from August to January and February to July, respectively. Samples were collected monthly from the cooling tank between February 2010 and February 2011, in the morning. Next, they were homogenized and packed in 40-mL plastic flasks, containing the preservative Bronopol® and later sent to the laboratory for urea nitrogen analysis. Although March 2010 exhibited greater ureanitrogen concentration (25.4 ± 4.4 mg/dL) and November the lowest mean (12 ± 0.4 mg/ dL), there was no significant variation in milk urea nitrogen in samples collected from cooling tanks during the rainy and dry seasons.

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.

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.

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 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 aim of this work was to study the physiological responses of three contrasting cultivars of sugar cane subject to water stress and rewatering, The experiment was carried out in a greenhouse, where the cultivars SP83-2847, SP80-1842 and SP81-3250 were grown in pots. The first assessment was done after 85 days of planting, then two treatments were implemented, i.e. without water stress (-D) and with water stress (+D) by withholding water for 15 days and rewatering imposed for 12 days after the stress period. Cultivars SP81-3250 and SP80-1842 showed a higher decline in the Fv/Fm ratio, leaf relative water content (RWC), leaf water potential (Ψw), SPAD index and photosynthetic pigments due to water deficit. Drought caused less damage in the physiology of the variety SP83-2847, and it still showed rapid recovery during rewatering, including for the stomatal conductance (gs), so this variety had better adaptation under this condition. The traits Fv/Fm, Ψw, RWC, SPAD index and photosynthetic pigments present as potential physiological indicators in order to select tolerant sugar cane cultivars to water deficit. The trait gs is more effective in differentiating the tolerant cultivars during rewatering.

The present study aimed to use DNA markers to select plants for the first and second backcross (BC) of two distinct populations of common bean, carrying the QTL for resistance to white mold and RAPD and microsatellite markers to identify the plants of the BC population more similar to their recurrent parent. For this, it was used the lines G122 (resistant - P1) as donor parent and VC3 (susceptible - P2) as recurrent parent for generation of the population F1RC1-GV evaluated for resistance to white mold by means of the SCAR Phs and genotyped with RAPD primers. In the F1RC2-EM population were used the lines Ex Rico 23 (resistant) as donor parent and M20 (susceptible) as recurrent parent evaluated for resistance to white mold, by means of RAPD primers O12.1600 and O15.1800 and genotyped with microsatellite (SSR) primers. Genetic similarity (sgij) between each BC plant and the recurrent parent was estimated using the Sorensen-Dice coefficient. The proportion of the SSR alleles derived from the recurrent parent was also estimated and, simultaneously, genetic similarity and the proportion of SSR alleles were efficient for identifying plants more similar to the recurrent parent. It was found that marker assisted selection (MAS) contributes to reducing the number of BC in at least a generation.

This paper aimed to characterize the main agricultural productive systems of the county of Ibimirim in the semi-arid region of the state of Pernambuco, Brazil, in order to obtain data that can serve as subsidy to the implementation of agroforestry systems. Different productive unities were characterized through semi-structured interviews with local agriculturists selected through a stratified sampling. Each layer was composed by the main activity executed by the family which correspondent to: group 1: irrigated agricultural systems; group 2: traditional systems and forest extractivism; group 3: apiculture; group 4: handicraft fishing. The sample was composed by 5% of the small agriculturist in the groups 1, 2 and 3 and 2% in the group 4, due to this group being more homogeneous. The irrigated agriculture stood out in economic terms, althought it has demonstrated limited autonomy due to external raw materials dependence in addition to contribute to soil and hydric resource degradation. The traditional systems high adaptability and the apiculture conservationist character have generated a low impact under the local ecosystems. Fishing, forest extractivism and forest management are activities that allow the agriculturist maintenance in the rural environment and constitute a source of revenue during the dry season. The activities diversification and the integration of different productive systems has been a concrete possibility for income generation and improvement in the life quality of the families in the region. This way, the agroforestry systems of multiple use must be priority in rural development programs for the region sustainability.

This paper aims to evaluate the quality of yellow mombin fruit in different maturation stages from clones cultivated in Ceará - CE. For that 'Capuan', 'Lagoa Redonda', 'Genipabu' and 'Gereau' clones was harvested, at different maturation stages, being: 1 (green fruit), 2 (25% to 50% of yellow skin), 3 (75% of yellow skin) and 4 (100% of yellow skin). The fruits were transported to the laboratory of Chemistry of IFCE Campus Limoeiro do Norte - CE, and then were made a selection and the classification of maturity stages by skin color. The experiment was conducted with four treatments (maturation stages) with five replications each consisting of 10 fruits. It was evaluated soluble solids, titratable acidity, pH, vitamin C and Ratio. To the physical parameters, was using only yellow mombin of 3rd stage, and was evaluated weight, length diameter of fruit. The clones presented differences physico-chemical. The 'Gereau' clone had the highest soluble solids. In the stage 4, independent of the clone, was verifying the higher soluble solids content and lower acidity, thus presenting, higher condition of acceptability by consumers and the industry, and the point of harvest more appropriate.