Aiming the characterization of genotypes and estimate the genetic divergence through morphological markers of the sweet-potato, an experiment was developed, in the year 2007, in the municipality of Junqueiro, in the Alagoas State, composed of nine clones and two local varieties, in the randomized complete block design with three replications. Were evaluated fourteen characteristics of the aerial part and seven of the roots through morphological descriptors. For the assessment of genetic divergence was used the methodology of the principal components made by the group and the methodology of Tocher. It was wide phenotypic variability among genotypes based on morphological markers. The results showed that the first three components of the variables of aerial part explain 77.08% and in the first two components of the root system of variables explain 72.13% of the variability exists. Six groups were formed, being that group I restrained three genotypes, the groups II, III and IV have been formed by two genotypes each, and the groups V and VI contain a genotype each. The results indicate; using the two methodologies, have wide phenotypic and genotypic variation among genotypes of sweet potato-based on morphological descriptors, indicating prospects for the breeding program of this culture.

The albizia is a species arbores of the Leguminosae - Mimosoideae family (Momosaceas), native of Tropical Asia and characterized for presenting a speed growth, ability to fix nitrogen and to improve the structure of earth, especially in areas degraded, having uses multiples and facility to co associate with cultures agricultural. The research was lead in two experiments with the objective of to identify methods to superation of dormancy in seeds of albizia and to verify the effect of light and temperatures in germination of this species. In first the seeds were submitted the twelve methods to superation of dormancy: humid heat, immersion in hot water, immersion in sulfuric acid, and escarification mechanic, beyond of the witness, being determined the percentage of germination of seeds seard and deceased. In second experiment, after treatment with sulfuric acid for 10 minutes, the seeds were sowed in tabledoch paper type Germitest and put to germinate under nine combinations: continue light and constant temperature of 25oC; continue light and constant temperature of 35oC; continue light and alternated temperature (35oC/8h and 25oC/16h); dark continue and constant temperature of 25oC; dark continue and constant temperature of 35oC; dark continue and alternated temperature (35oC/8h and 25oC/16h); alternance of light (light/8h and dark/16h), 25oC; alternance of light (light/8h and dark/16h), 35oC and alternance of light and temperature (light/35oC/8h and dark/20oC/16h). Conclusion the specie Albizia lebbeck presents seeds dormancy, detach-itself the escarification mechanic and the sulfuric acid as efficient methods to the superation of dormancy; the seeds of albizia are insensitive to the light and your germination was not influenced by the temperatures useds.

The study area involves the territory limit of the Boa Vista municipality, 446.30 km2, situated in the Cariris Velhos homogeneous micro region, semi-arid region of the Paraiba State. The present work had as objective the elaboration of thematic maps of the space-time evolution of vegetal covering classes, period 1987/2004, of the Boa Vista municipality using TM/LANDSAT-5 satellite's digital images and photo interpretation techniques and images digital processing, available in the SPRING v. 4.2 software, beyond field work. The maps were elaboration be using the segment images supervised classification method and edited by SCARTA module. The results had indicated that the covering vegetal class most conserving, dense to semi dense, suffered reduction of 13.93% between 1987 and 2004; in this period the percent of areas with semi-dense to semi-sparse class was practically steady, diminishing only 0.87%; besides, the more critical covering class (semi-sparse to sparse and sparse + exposed soil) had increased 9.02% and 5.73%, respectively. These results are related with the raised use of lands for cattle the extensive one, as well as for the lack of income of the agricultural population that without option uses the vegetation in the firewood form.