This work had as objective to evaluate the emergency and the survival of seedlings of imbu tree (Spondias tuberosa Arruda) in caatinga. The assay was carried through of January of 2001 the December of 2004 with 37 plants of imbu tree, selected to perhaps in area of caatinga of the Embrapa Semi-Árido, Petrolina - PE. In each plant four quadrants of 1 m2 had been demarcated randomized below of the pantry for counting of the emergency and survival of seedlings. The comments had been carried through to each 15 days in the rainy station and 30 days in the dry station. A rain gauge was installed in the area of the experiment for attainment of the values of the occurred precipitation during the period of evaluation. The biggest indices of emergency had occurred in the period of bigger precipitation with 57,89 plântulas.m-2, in average, for plant-mother in the rainy station of 2004. Few seedlings had survived until the end of the period of evaluation. The stadium seedling is most critical for the survival and development of the imbu tree in caatinga. The biggest volume of precipitation significantly contributed for a bigger tax of germination and emergency of seedlings of imbu tree.

This study had the objective of surveying the occurrence of tubers in native imbu (Spondias tuberosa) trees in the Northeast of Brazil. It was carried out in 36 native trees in the Caatinga area of the communities of Sitio Papagaio (Juazeiro-BA), Saco Farm (Jaguarari-BA) and Alto do Angico (Petrolina-PE), from August 2000 to November 2002. In each community, twelve plants were randomly selected for tuber extraction. The following variables were analyzed: plant height, trunk diameter at soil level, canopy diameter, as well as number and total weight of tubers per tree. In the community of Sitio Papagaio, in average, 978.42 tubers per tree were collected, with a total weight of 1731.2 kg. In the community of Saco Farm, in average, 1011.58 tubers were collected, with a total weight of 1820.13 kg. In the community of Alto do Angico, in average, 731.58 tubers per tree were collected, with a total weight of 1370.09 kg. The occurrence of tubers per tree in the communities was, in average, 907.19, with a total weight of 1352.12 kg per tree.

This work was carried out in order to evaluate the mycorrhizal fungi in four surrounding areas of Parque Estadual da Serra do Mar, in Ubatuba (SP), with the following covering vegetation: banana plantation interposed at forest, cassava plantation, capoeira area and secondary forest. Soil samples were collected in July 2003 and March 2004. Regarding arbuscular mycorrhizal fungi (AMFs), the crop areas of banana and cassava showed higher spore number than forest and capoeira areas in the winter. In the summer, only cassava area showed high spore production. The rainy season provided a higher number of AMFs species compared to the dry season, in both forest and banana areas. However, regarding the occurrence of different AMFs species there was no clear pattern as to wet or dry season.

The insects of the Chrysopidae family are very important for biological pest control. The present work had the objective of determine the consumption capacity of eggs of three moths species by Chrysoperla externa larvae, besides to verify the larvae-adult period viability, duration of the larval period, and the total mass (g) of consumed eggs. The experiment was accomplished in laboratory conditions, under controlled temperature (25 + 2 ºC), UR (75 + 10%) and photoperiod (14:00 H). Insects of the first generation (F1) were used, being three treatments with 30 replications, under DIC. The obtained results showed that the eggs of S. cerealella and A. kuehniella provided higher viability for the larvae-adult period of C. externa; the duration of the larval period of C. externa was smaller when the eggs of A. kuehniella were used as food; and the larvae of C. externa, preferentially consume the eggs of A. kuehniella, being the higher consumption in the third ínstar.

The knowledge of hemoglobin types may help in near future the selection of animals, serving as a genetic marker. The present work aimed to determine the types of hemoglobin in Santa Ines crossbreed sheep, and verify whether it has correlation with the erythron. It were collected 49 blood samples from different healthy Santa Ines crossbreed sheep, from Mossoró city, RN, Brazil. These samples were used for determination of packed cell volume, red blood cells counts, hemoglobin concentration, hematimetric indices (mean corpuscular volume - MCV, mean corpuscular hemoglobin - MCH, and mean corpuscular hemoglobin concentration - MCHC), and electrophoretic separation of hemoglobin. The electrophoresis revealed a slow band characterized as hemoglobin A (HbAA), a fast band characterized as hemoglobin B (HbBB) and both bands in the heterozygous hemoglobin A and B (HbAB). The type HbAB was the most frequently found, but all found types were present at representative amounts. The statistical analysis for comparison between the hemoglobin parameters and each parameter of the erythron revealed significant difference only for MCH; the other measurement were not statistically different. Thus, the hemoglobin types (HbAA, HbBB e HbAB) did not influence the erythron of sheep.

The tebuthiuron residue, used in the sugar-cane culture, can be found in soil until two or more years after its application. Recent researches are being done using the phytoremediation in the attempt of removing it from the soil. The purpose of this work was to evaluate the effectiveness of the green manure use in the phyitoremediation of the tebuthiuron herbicide. The evaluated species were: Cajanus cajan, Canavalia ensiformis, Dolichos lablab, Pennisetum glaucum, Estizolobium deeringianum, Estizolobium aterrimum and Lupinus albus. These were sown and cultivated in pots containing soil treated with different doses of tebuthiuron (0.0; 0.5; 1.0; and 1.5 kg.ha-1). A control treatment without green manure, submitted to the same dosages, was kept. Sixty days after planting, green manure aerial part of all plants were harvested and soybean was sowed in the same pot, to bioassay accomplishment. Sixty days after sowing, the soybean plants were harvested, being the following evaluations carried out: height of plants, phytotoxicity symptoms and plants above ground dry biomass and leaf area. Until 0.5 kg.ha-1 tebuthiuron dosage, the species that better phytoremediated this herbicide was L. albus. When the soil was treated with tebuthiuron at 1.0 kg.ha-1, the C. ensiformis, followed by L. albus and S. aterrimum, they were the treatments that better phytoremediated tebuthiuron because results in highest plant height, above ground dry biomass and lesser phytotoxicity symptoms and still the biggest foliar area of the soybean plants. When the tebuthiuron was applied at 1.5 kg ha-1 dosage, it was impossible to evaluate the phyitoremediation, as the tested plants were eliminated.

In order to analyze the morphological variability in natural populations, fourteen accesses of Manihot pseudoglaziovii were studied, collected in the Curimataú Paraibano micro-region, in Paraiba State, besides an esculent M. Cranz access (cassava) and a natural hybrid between these two species. Five plants of each access were multiplied through cutting and then cultivated in an experimental area of the PPGZ/CCA/UFPB under standardized conditions, aiming a homogeneous externalization of each genotype. For the morphometric analyses, 20 morphology characters were studied from which analyses of variance and t-test were done, for each character separately. Pearson correlation analyses between pairs of characters were also carried out, once the occurrence of significant correlation justifies the use of multivariate analyses. The cassava access differed regarding the accesses of maniçoba and manipeba, according to the first canonic axis of the multivariate variance analysis. On the other hand, the presumed hybrid between the cassava and maniçoba differed from the others regarding the second canonic axis. The 14 maniçoba accesses presented variation, but they did not differ among themselves, although accesses 1, 2, 8 and 13 revealed themselves distant regarding the other accesses of this species.

Natural regeneration depends on a series of environmental factors, which determine seed and seedling bank composition, and plant community structure of a site. Jurema preta (Mimosa tenuiflora (Willd) Poiret) is a pioneer legume tree that colonizes degraded sites of the Caatinga and produces a great number of seeds in several months of the year. In despite of its abundance, there is little information on the dynamics of jurema preta natural regeneration. Thus, a study was carried out to find out if seed germination and plantule survivorship under jurema preta canopy are affected by the annual April or July pruning of fine branches of a few jurema preta plants in a native Caatinga thicket submitted to continuous cattle browsing. Data analyses show that seed germination occurs in the beginning of the rainy season, and that in this period of moisture availability, plantule bank is composed by 17 to 58 thousand seedlings/ha. This number decreases during the rainy season, until it reaches a minimum of 3.7 to 7.5 thousand seedlings/ha, at the end of the dry season, in an ecological strategy of recurrent annual colonization. April or July pruning shows no consistent effect on jurema preta natural regeneration in areas submitted to bovine browsing, although plantule number was temporary and positively affected by pruning in one of the experimental site at the peak of the rainy season.

The objective of this work was to evaluate the residual nitrogen contents behavior in a soil fertilized with four different nitrogen sources (ammonium sulfate, calcium nitrate, urea and monoamonium phosphate) at dosage of 80 kg.ha-1, divided in 2, 3, 4 and 5 parcels, applied through drip irrigation on the melon production, in field conditions, at the Fazenda Cajazeiras, located in Tibau, RN, Brazil. A 4 x 4 factorial, completely randomized block split-plot design, with four replications was used. Soil samples were collected before planting and 40 days after the first nitrogen use to the depth intervals of 0-15, 15-30, 30-45 and 45-60 cm, on which total mineral nitrogen, NH4 +, NO3 - e NO2- was determined. A differentiated behavior of the nitrogen sources regarding the ammonium furnishing to the soil was observed, existing a decreasing tendency of the ammonium contents with the increase of the fertilization partitioning and soil depth. For nitrate the highest concentrations were found on the surface interval and no effect of the fertilizer partitioning was observed. The highest concentrations of nitrite were found on the 30 - 45 cm depth interval and the total mineral nitrogen was concentrated mainly on the root absorption region. The biggest accumulation of total mineral nitrogen in the soil was originated from employment of MAP and ammonium sulfate and the lesser accumulation was due to urea use.

The objective of this work was to evaluate the effect of four nitrogen sources (ammonium sulfate, calcium nitrate, urea and monoammonium phosphate) at 80 kg ha-1, applied 2, 3, 4 and 5 times through drip irrigation on the production and characteristics of the melon, under field conditions, at the Cajazeiras Agricultural Farm, located in Tibau, RN, Brazil. The experiment was carried out in a completely randomized block design, in a 4 x 4 factorial scheme, with four replications. The melon yield was measured considering total number and weight of the fruits, the number of marketable fruits per hectare and size of the fruits. Generally speaking, the results showed that melon plants presented similar response to all used nitrogen sources, notably to the MAP applied three times; that the number of nitrogen applications did not affected the evaluated parameters regarding production and quality of fruits; and that the used nitrogen sources and the application number of the fertilizers resulted in higher amount of types 6, 7 and 8 fruits (fruits with average size).