The objective of this study was to estimate the genetic potential of two maize populations, in order to verify their genetic potential under two production systems (with and without nitrogen stress). So, 49 half-sib families (FMI) of the population UFVM 100 and 49 FMI of the population UFVM 200 were randomly taken. The 7 x 7 lattice design was used, with two replicates. The high nitrogen level was established with planting fertilization more two side-dressing fertilizations, so totaling 120 kg/ha N (40 kg/ha N in planting fertilization; 40 kg/ha N at the 15 days after emergency - DAE; 40 kg/ha N at 30 DAE). The low nitrogen level was only 20 kg/ha N in planting fertilization. The experimental plot consisted of one row with 5m length and 0.90m spacing between rows and 0.20m among plants inside the rows. All experiments were subjected to water deficit (irrigation interruption) at flowering stage, during 7-day period, until soil water potential was between -0.09 to -0.1 MPa. The grain yield was evaluated in each plot. The variance analysis relative to those 49 FMI of each population in each production system was accomplished according to recommendation by Cochran and Cox (1957), whereas the estimates of the genetic parameters were performed according to method 1 presented by Silva et al. (1999), when considering the lattice experiments. After the individual analyses, those 15% more productive FMI were selected in each production system to estimate the expected selection gain when recombining them. It was found that only the population UFVM 100 shows genetic variability to be explored by selection based on half-sib families, for grain production under low N availability conditions; the estimates of the genetic parameters associated to grain yield were similar as for high and low nitrogen; the consistence of the agreement level between the families´ performances under low and high availability of nitrogen was low, therefore pointing out the need for conducting a specific improvement program when the objective is to obtain material adapted to nitrogen stress conditions.

Spodoptera frugiperda is a species polyphagous that attacks several cultures economically important in various countries. It is known in the larval phases as fall armyworm and it is to main curse of the culture of the corn in Brazil.It was found recently fed her in plantings of cassava in São Luís and Itapecuru Mirim (MA). As the knowledge of the biology of the insect is of fundamental importance for the development of handling strategies, inside of the integrated handling of curses, the work aimed at to study the biology and the behavior of S. frugiperda in cassava leaves, maids in laboratory conditions. 60 coming caterpillars of the creation were used in articial diet. After the appearance the larvas were individualized in disposable plastic glasses with capacity for 100 ml and fed with cassava leaves, that they were changed every other day, or according to need. The experiment was led in climate chamber, regulated for temperature of 25°C, relative humidity of 60 + 10% and fotofase of 14 hours. The appraised biological parameters demonstrated the medium duration of the total cycle of 39,93 days, distributed in 6 or 7 you urge, where the species presented larval viability, pupal and of superior adult to 75% and, percentile of of 4% and 22,97% in pupas and adults, respectively. The fecundity was of 70,84% and the adults' of 77,08% viability. Being ended that the culture of the cassava assists to the demands nutricionais of S. frugiperda.

The work was conducted in two environments of caatinga, occurring in the Moacir Lucena accomplished, Apodi - RN. 12 plots have been demarcated 10 x 20 m, randomly distributed in each environment, characterized as follows: Area I - managed area and Area II - area of legal reserve of Accomplished. In each plot were sampled all individuals with CAB ¿ 10 cm. In Area I were sampled 130 individuals, five families and eight species, while in Area II, 244 individuals, four families and seven species. The Mimosoideae and Boraginaceae families are highlighted by number of individuals. Caesalpinea bracteosa presented greater number of individuals in the environment I and Auxemma glazioviana the environment II. The environment I made highest diversity of the Shannon- Weaver (H'), 1,10. In the environment I Caesalpinea bracteosa and Auxemma glazioviana were the species that showed higher frequencies, densities and dominances relatives, index of importance and value of coverage. Auxemma glazioviana presented highest density, dominance, frequency, IVC and IVI in the environment II. In the environment I most individuals presented stem diameter of between 11 and 21 cm, while the environment II, less than 11 cm.

In the cemented plots, between July/93 and August/94, in the campus of the Federal University of Paraíba, in João Pessoa (lat 7o 02' 30'' S and long 3o 45' 06' W), experiments were carried out as follows: in the plots A, B and C podzolic soil was put into them and amended with 25kg of sugarcane bagass and added 80 earthworms (A), 10kg of bagass and 80 earthworms (B) and unamended and added 40 earthworms (C). The results showed that the sugarcane bagass improved same soil properties, by raising the pH and Ca++, organic C, S.O.M., and N levels. Microbial biomass (BM), in mg CO2-C.100g-1 of soil and microbial activity (MA), in g.year-1, showed a means: (A) BM= 7.88mg and AM= 1.54g; (B) BM= 10.44mg and AM= 1.59g; (C) BM= 3.29mg and AM= 1.25g. Ratio Cmic : Corg were higher in the plots with greater amount of sugarcane bagass (0.84% in A, 0.64% in B, and 0.33% in C). Earthworms population density (individuals.m-2) was initially 13 in the three plots and increased to 35 in A, 40 in B, and to 30 in C respectively. The results obtained here suggest that 10kg of sugarcane bagass enhanced soil microbial biomass and activity, and the earthworm population assayed.

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.

The quality of irrigation water is one of the environmental factors that can affect the initial growth of the culture of melon. This study aimed to evaluate the emergence of seedlings of melon, hybrids Goldex and Vereda in different levels of salinity of irrigation water. The study was carried out at the Seed Analysis Laboratory of the Department of Crop Science of the UFERSA, Mossoró, RN, between February and April 2007. The treatments were organized in a completely randomized design in factorial scheme 2 x 6 (two hybrids of melon plant Goldex and Vereda, and six levels of electrical conductivity of irrigation water: 0,45; 1,30; 2,15; 3,00; 3,85; 4,70 dS m-1), with four replications. Evaluation of speed of emergence-index, height of the aerial part of the seedling, dry mass of the aerial part of the seedling and seedling emergence. The salinity interfered in all parameters measured, and that as of 2.5 dS m-1 were more harmful to the hybrid Goldex that Vereda.

During the germination process, the impermeability of the tegument and the humidity of the substratum they influence the reidratação of the seeds, metabolic activation and consequent growth of your embryonic axis. Therefore, the present work was led with the objective of evaluating the effect of the removal of the tegument in the germination and vigor of seeds of pinhão-tame (Jatropha curcas L.) in different volumes of water in the substratum. After the seed shoud treatments they were installed in germination model Mandelsdorf under regime of natural light in the constant temperature of 30ºC. The experiment was set up in a completely randomized factorial design outline 2 x 4 (2 - with and without tegument and 4 - humidities 2,0; 2,5; 3,0 and 3,5 times the weight of the paper (g).). The evaluations were accomplished daily (primary roots protrusion) and to the 07 and 10 days of the beginning of the test, being computed the normal seedlings. In agreement with the results obtained in the present work, the retreat of the tegument can be ended it affects the germination and vigor of the seeds negatively, that the when the substratum is humidified with volume of water (mL) in the strip from 2,0 to 2,5 times the weight of the paper, happening the reduction of the germination and vigor when the substratum is humidified for superior values to this. Presenting better acting when the substratum is humidified with volumes of water (mL) equivalent to 3,0 and 3,5 times the weight of paper germitest (g), happening the reduction of the germination and vigor when the substratum is humidified for inferior values to these.

Brazil possesss potential for attainment of great amounts of apicultural products, what it differentiates it of the too much countries that, normally, harvests an only time per year. However despite the diversity of the apicultural flora and the high existing food concentration in the rainy period, during the dry station, a scarcity of apicultural grass e occurs, consequently, of food for the bees being necessary a complementary feeding of this form assuring the productivity and the profits. The feeding of the bees of course is very selective, them is adapted in the adult phase to an feeding eliminates, however, these unbalanced fluids little is concentrated and its composition with predominance of sugars, thus needing complementing in the diet with a rich food in proteins as form is pólen.Dessa is necessary to know foods conventional and alternative for the period of between harvest diminishing the loss of the brief produção.Esta revision presents excellent aspects of the feeding of the bees relating its chemical composition, nutritional value and functional properties.

The increasing importance of sunflower leads to studies on seed pathogen, to guarantee crop sanity and to provide identification of pathogens in new areas. Genotypes seeds lots produced in Embrapa Soja assays carried out in tree cities of the State of Maranhão, Brazil (Balsas, São Luís and Timon) were analyzed, with the objective of evaluating sanitary quality of sunflower seeds. Sanitary analysis was performed by blotter test method and identification of fungi genera was based on morphological features. The occurrence of Fusarium sp., Alternaria spp., Curvularia sp., Dreschelera sp., Aspergillus sp., Penicillium sp., Phoma sp., Trichoderma sp., Botrytis sp., Rhizoctonia sp., Rhizopus sp., Colletotrichum sp., Chaetomium sp., Cladosporium sp. and Sclerotinia sclerotiorum was observed in seeds of sunflower, with variable incidences.

The objectives of this work were identified and characterize the allelopatic activity of extracts obtained from Arctium minus (Hill) Bernh (Asteraceae). The fitotoxic activity of organic extracts (1 e 100 mg.L-1) and aqueous extract (5,00 e 0,05% m/v) on the germination and radicular growth of the monocotyledon Sorghum bicolor L. (sorghum), and the dicotyledon Cucumis sativus L. (cucumber) were evaluated. The results showed the presence of allelopatic activity variable in according to the extract concentration and with the target plant. The intensity of induced inhibitory effect was higher for the ethanolic extract in concentration of 100 mg.L-1 for Sorghum bicolor L. The results also indicates the existence of the potential use of Arctium minus (Hill) Bernh ethanolic extract as a natural herbicide and open perspectives for the research of the constituent(s) with higher allelopatic activity.