The research was carried out to evaluate the quality of waters used in the irrigation of agricultural areas of Congo region, Paraíba State, Brazil. The water samples were collected in Cordeiro dam, in wells and in river, in two periods of the year, rainy (May/2006) and dry period (December/2006) and analyzed under the qualitative aspects of salinity, sodicity and toxicity of ions. For the studied conditions and in agreement with the evaluated parameters in both periods, most of the samples of water, as for the salinity, were considered normal for the use in the irrigation since special practical of soil and water management are adopted; as the toxicity of the ion sodium, more than 40% didn't present restriction to the use. In relation to the toxicity of the ion chloride, in the rainy period, 61% of the samples didn't indicate restriction to the use for irrigation and in the dry period, 44% presented restriction varying from low to moderate.

This work was done in order to characterize the water holding capacity and availability to plants in three soils of coastal tablelands in the state of Paraíba using tensiometry in areas cultivated with sugarcane. The water retention curves were determined for the Neossolo Quartzarenico, Latossolo Amarelo, Latossolo Coeso soils in the depths of 0 - 30cm and from 30 - 60 cm, by the Richards extractor method and by tensiometens in PVC columns in a greenhouse in the first phase and in a battery of field tensiometers in the second phase, in the tensions of 10, 20, 30, 40, 50 and 60 cm Hg. The water retention in the soils was significantly affected (p<0,01) as a function of the tensions (TS) applied. The same effect (p<0,01) was seen for the factor soil (S) and for the interaction (TS x S) both for the extractor and the greenhouse methods as well as for the field method. According to the study of the regression analysis, the mathematical model that showed the best adjustment was the decreasing quadratic. The values of moisture content found showed the most abrupt variations at the lowest tensions. The moisture content for the Neossolo Quartzarenico demonstrated under field conditions the importance of the structure for soils retaining more moisture in the tensions studied in relation to the laboratory and greenhouse methods. Even though the clay content were similar for the Latossolo Amarelo and the Latossolo. Coeso the greatest moisture retentions were observed in the Latossolo Coeso.

Espinheira Santa (Maytenus truncata Reis) it is a plant used for medicinal ends in the hiperacidez treatment, gastric ulcerations, cutaneous disease as, eczems, constipation and cancers. She possesses properties analgesic, antiseptic and healing, being found in the proximities of Rio de Contas in Jequié - BA. Due to the intense use for the population and exploration for the erveiros, the species is disappearing of the area. With that, it is made to study the species in molecular level seeking to subsidize a strategy of protection of the same. Aiming at to evaluate and to adapt a methodology as tool to be used in studies of molecular biology was tested four protocols of extraction of DNA, and the protocol that obtained the best results in the tests of quantification of DNA in agarose gel and photometer spectrum was it of Ferreira & Grattapaglia (1998) with modifications in the act of the maceration and of the centrifugation. DNA was isolated I integrate and in great been presenting in it measured a degree of purity (A260/A280) in photometer spectrum of 1,78 and a concentration of 1846 ng/ml.

The objective of the present experiment was evaluate the effect inter cropping systems with the culture of the maize on the production components, aiming at to maximize the grain production and to increase availability of pastures for animal feeding. The treatments had consisted of the culture of DKB-950 maize (Hybrid Simple Modified), on three grassy species of (Brachiaria decumbens, Brachiaria brizantha and Panicum maximum cv. Tanzania) inter cropping systems and conventional tillege of soil. In foundation one applied 0, 35, 50 and 4 kg ha-1 of N, P, K and Zn respectively in the sulphate form of ammonium, simple superphosphate, potassium sulphate and zinc Sulphate. In covering it applied if 120 kg ha-1 of N. the used espaçamento was of 0,80 x 0,20 m, The experiment was arranged in a randomized complete block design, with four repetitions. The components of the production of the maize had not been affected by the studied systems of inter cropping, except for the number of spikes and production of grains, where the maize cultivated inter cropping systems with Brachiaria decumbens (4.787 kg ha-1) was better that the Tanzania (3.683 kg ha-1). The accumulation of dry mater presented significant difference between the treatments, in the which Tanzânia presented greater accumulates of dry mater.

The objectives of this work were to determine the genetic correlation and define the strategies for obtain maize cultivars for traditional production system. For that, the white maize landrace population was rescued in Barbacena, MG and two experiments were installed with 100 half sib progenies using lattice triple in Barbacena and Campos dos Goytacazes, RJ. The estimates of correlations were different for each local requiring different strategy for trait selection due to contrast edaphoclimatic condition. The additive genetic correlationswere significant among primary production components and the productivity. On the other hand, the additive genetic correlations among primary and secondary production components were non significant. The traits related with flowering showed genetic correlation with productivity and primary production components, but not for secondary production components. Concluded that the increasing of productivity can be reached with direct or indirect selection for all environments; the indirect selection for number of plants/ area and number of plants with ears with kernels can be viability strategy in experiments in the small producers or by themselves instead of to select directly the productivity; the selection for increasing productivity without change the plant architecture is possible and adequate for traditional production system.

The semiarid is characterized for presenting precipitations concentrated in short period of time, form that to most of the year the ground are displayed the strong insolation and to the raised hídrico deficit. On the other hand, the estacional variation of the climate affects the water content of the ground and as consequence the biological activity and the losses of C, mineral N and C-CO2.The purpose of this research was to analyze the losses of C, mineral N and C-CO2 of the ground in a microbasin, that passes for a process of environmental degradation, located in the Fazenda Experimental Bacia Escola/CCA/UFPB in São João do Cariri - PB, during the period of a translation, of the years of 2003 and 2004. It was defined a toposequence and chosen points of determination for the evaluation of the reserves of carbon, mineral nitrogen and microbic activity by means of the C-CO2 production. The biggest amounts of C had been verified in the areas of pediment and the minors in the area of side slopes; The amounts of mineral N was not influenced by the position of the ground in the toposeqüência; The biggest liberation of C-CO2 happened in the areas of pediment followed by the flood plain and half hillside, places with the biggest amount of of water in the soil.

The purpose of this study was to assess the seedling growth of cashew and tamarind rootstocks with nitrogen fertilization. To this end, two experiments were conducted in the Production Sector of the State University of Mato Grosso do Sul (UEMS), at the University Unit of Cassilândia (UUC), Brazil. Five nitrogen levels were tested: 0, 400, 800, 1600 and 3200 mg/dm3 of N in the substrates. The experimental design was in randomized blocks with 4 repetitions and ten plants per parcel. 20 ml of urea solution were added to each application from each treatment containing 45% nitrogen. The application was repeated four times. Ninety days after planting, we assessed plant height (cm), number of leaves/seedling, plant diameter (mm), roots, aerial part, root and total dry matter (g/seedling). Nitrogen fertilizer in doses of up to 2000 mg/dm3 of N in the substrate ensures better cashew and tamarind rootstock seedling quality. A 3200 mg/dm3 dose of N in the substrate had a growth depression effect on the rootstock seedlings.

This work was carried out from october to december, 2005, in Agropolo Assu-Mossoró region, RN, Brazil, with the objective of evaluating the effect of nitrogen and potassium doses on fertilization efficiency of melon crop. Three simultaneous trials were performed in adjacent areas, each one receiving a different water amount (L1=0.76NTI, L2=0.9NTI and L3=1.04NTI). Experimental design was a randomized blocks in a factorial scheme with three replications. Treatments consisted of combination of three doses of both nitrogen (N1=42, N2=84 and N3=126 kg ha-1) and potassium (K1=106, K2=212 and K3=322 kg ha-1), plus two additional treatments (N2K0 e N0K2), applied only with intermediary water amount. N2 e K2 was the levels recommended for melon. Indexes of agronomic efficiency of fertirrigation were determined for nitrogen, potassium and irrigation depths. Agronomic efficiency was influenced by N and K doses, irrigation depths and by factor interaction. Treatments L3N1K1 (305.57 kg kg-1) and L3N2K1 (132.63 kg kg-1) presented higher efficiencies for fertirrigation with nitrogen and potassium, respectively.

The experiment was carried out at Universidade Estadual Paulista - UNESP, Jaboticabal, SP during the period of March to May of 2006, with the objective of evaluating the production cost and profit margin of crespleaf lettuce cv. 'Verônica' and American lettuce cv. 'Lucy Brown' in sole crop and intercropping with rocket cv. 'Folha Larga'. The determination of the production cost was based on the total operational cost. The estimate of the operational cost for crespleaf and american lettuces and rocket in sole crop were about R$ 5, 446.42; R$ 4, 923.25 and R$ 3,829.84, respectively. The estimate of the total operational costs of crispleaf lettuce x rocket and American lettuce x rocket intercrops were about R$ 7,195.46 and R$ 6,041.38 per hectare. Higher operational profits were observed in intercropping systems, being highest in the american lettuce x rocket intercrop, with R$ 45,437.68 per hectare.

The experiment was carried out to evaluate the nutrients content in leaves of lettuce intercropped with carrot in strip-intercropping under different planting densities of component crops. The experimental design used was of randomized complete blocks in a 4 x 4 factorial scheme with three replications. The treatments consisted of the combination of four lettuce-planting densities (40%, 60%, 80% and 100% of the recommended sole crop density - RSCD) with four carrot-planting densities (40%, 60%, 80% and 100% of the RSCD). Evaluations for P, Na, Ca, Mg, and K contents were made in the lettuce leaves. There was a significant interaction between lettucedensities and carrot-densities on P content in lettuce leaves. Higher contents of Na and Ca (58.40 and 7.58 mg/plant) were observed in the lettuce-densities of 52% and 47% of the RSCD. The contents of Na and K held constant with increasing carrot-densities. Higher contents of Mg (30 and 15 mg/plant) were observed in the density of 40% of the RSCD both in lettuce and carrot crop.