The residual effect of natural insecticides was evaluated on adults of Sitophilus zeamais Mots. (Coleoptera: Curculionidae) on stored corn grains. Clove (Syzygium aromaticum L.), white pepper (Piper nigrum L.), neem (Azadirachta indica A. Juss) and silica dioxide powders were tested as well as neem, eucalyptus (Eucaliptus globulus Labill and Eucaliptus citriodora Hook.), eugenol, andiroba (Carapa guianensis Aubl.), rosemary (Lippia gracillis HBK.), cedar (Cedrela fissilis Vell.) and pequi (Caryocar brasiliense Camb.) oils. Powders were tested at concentration of 1kg/t in 50g-corn-plot and the oils at dosage of 50¿L in 20g-corn-plot. The plots infestation was accomplished using 20 and 8 adults (males and females) of S. zeamais being 0 to 15 days old, respectively, in the experiments with powders and oils. Silica dioxide caused 46.7, 38.3 and 37.5% of mortality, respectively, in the initial (soon after the treatment with the powders or oils) and at 60 and 120 days of storage periods, but the mortality induced by the other powders was inexpressive. In the three studied storage periods, silica dioxide was the more efficient in reducing adults emergency. At the initial storage period, all the oils caused mortality above 79%, however, after 60 and 120 days, mortality was lower than 2.5%. The adult emergency increased as stored period increased, although at 120 days the best performance was obtained using neem, followed by andiroba, cedar, rosemary and E. globulus oils.

The yield of lettuce plants cultivated under agrotextile protection was evaluated in conditions of high temperatures and intensity of radiation. The experiment was carried out at the experimental area of the Universidade Federal Rural do Semi-Árido, in Mossoró, Rio Grande do Norte State, Brazil, in a red-yellow argissol. The randomized complete blocks design was used, with four replications, in a 3 x 3 factorial scheme. The treatments consisted of the combination of three lettuce cultivars (Tainá, Babá de Verão and Verônica) with three types of plant protection (non-protected, direct-on-the-plant agrotextile protection, and nonwoven polypropylene tunnel with height of 0.5 m). The best yield performance was observed when the lettuce cultivars were grown in low tunnel.

A study was carried out to evaluate the influence of the elephant-grass x leucena intercropping, in aspects like productivity, crude protein contents and tillering of the intercropped elephant grass, besides trying to find the best planting density of this intercropping, aiming both highest grass productivity and better produced forage quality. The experiment was carried out at the Fazenda Experimental Vale do Curu, located in Pentecoste- Ceará, using a completely randomized blocks design with four treatments and four replications. The used treatments were: elephant-grass x leucena intercropping in the following spacings: 1.00m x 0.25 m; 1.00m x 0.50m; 1.00m x 0.75m and 1.00m x 1.00m, between the lines and plants, respectively. Cuts were done each 60 days, being six cuts during the experimental period. Leucena and capim-elephant were cutted 40cm and 10cm above ground 10 cm above the soil. The intercropping using leucena did not influence elephant-grass crude protein contents. The smallest tillers number and the biggest dry matter production of the grass occurred in spacing 1.00m x 0.25m, being this the indicated for this intercropping.

This work had as objective to evaluate spatial variability of physical characteristics of a Typical Haplocambids (CX), under papaya culture, by means of the geostatistic. The analyzed area presented 43 sampling points , where soil samples were collected, in the layer of 0 ¿ 0.2 m. In the soil samples granulometry, soil bulk density, particles density, water content at tension of 0.03 and 1.5 MPa were measured. From these analyses the total porosity and water availability were calculated. Data were evaluated by descriptive statistics and by analysis of the spatial dependence based in semivariograms adjustment. The variation coefficient indicated low variability for total and coarse sand contents, water content at tension of 0.03 and 1.5 MPa, soil bulk and particles density and total porosity; and medium for clay, silt e available water contents. Except for water content at tension of 0.03 and 1.5 MPa and particles density, the other variables presented space dependence, being the spherical and exponential models adjusted to all the semivariograms. The nugget effect had small contribution in the data total variance, indicating strong spatial dependence for fine sand and clay contents, total porosity and available water. The other variables showed moderate dependence. There was a great variation in the distance until where the physical characteristics of the ground present spatial dependence (reach).

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 purpose of the present work was to determine the size sample in order to estimate soluble solid contents in yellow melon plot. Samples of fifty fruits were taken of fifteen yellows melon plots grown in Mossoró- Assu Agricultural Pole. Evaluation for total soluble solid contents was done in all fruit samples. The procedures used for sample size estimation were bootstrap method and classical expression with 5% and 10% of error limit. The sample sizes estimated by bootstrap method, in average, yielded estimates close to those observed in the classical expression with 10% of error limit, although in ten plots these sample sizes were greater in the bootstrap method. The sample size recommended to estimate the total soluble solid contents in cultivated plots of melon fruits is fifteen.

Water shortage and saline soils of the Brazilian semi-arid northeastern region are limiting factors to the development of many plants. Jurema preta (Mimosa tenuiflora (Willd.) Poiret) is a small, multiple use tree that abundantly colonizes unfavorable sites, including environments with severe water stress. This work had the objective of investigating the tolerance of jurema preta seeds to water and salt stresses during germination. Seeds germination in polyethylene glycol (PEG-6000) and sodium chloride (NaCl) solutions was analyzed under five different osmotic potentials (0.0; -0.3, -0.6, -0.9 and -1.2MPa), in order to simulate water and salt stress, respectively, in four 100-seed replications for each treatment. Seeds were placed into 10cmx10cmx4cm boxes, and germination accomplished in BOD germinator adjusted to 30oC. The number of germinated seeds was monitored every 24 hours, and percentage and speed of seed germination were generated from these data. Mean percentage germination in the control treatment was ~95%, reducing to 63-53% at -0.9 to -1.2-MPa PEG solutions, and to 27- 9.5% at NaCl solutions at equivalent osmotic potentials. Velocity of germination index was more affected, and decreased up to 1/8 of the control, at -0.6 MPa. Jurema preta seeds showed lower tolerance to NaCl than to water stress, and this species can be classified as a glycophyte.

From leaves, stems and roots of healthy yellow passion fruit plants 93 isolates of endophytic fungi were obtained, with the colonization rates varying from 59.8 to 92.4% (leaves), 27.2 to 90% (stems) and 2.4 to 87.2 (roots). Twenty-nine of these isolates were evaluated for extracelular hydrolitic enzymes production (amylolitic, cellulolitic, lypolytic and proteolytic) and capacity to promove growth of yellow passion fruit seedlings. The isolates were identified as Fusarium (44.82%), Colletotrichum (37.93%), Acremonium, Glomerella, Curvularia, Alternaria and Aspergillus (3.45% each). The isolates EM11, EM50, EM172, EM20, EM81, EM72, EM135 and EM24 presented lypolytic activity with halos varying from 1.52 to 3.74 cm, and no isolate produced proteolytic, cellulolytic and amylolitic enzymes. Fifteen endophytic isolates promoted growth of yellow passion fruit seedlings, being the best EM173 (Alternaria), EM155 (Fusarium), EM139 (Curvularia), EM20 (Colletotrichum), EM6 (Acremonium) and EM151 (Colletotrichum) that increased aerial and root fresh biomass and root dry biomass of until 108.4, 204.4 and 70.2%, respectively, 90 days after the inoculation.

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.

The research was conducted in order to compare the methodology recommended on Seeds Analysis Rules, regarding substrate and temperature, for the germination test of linted and delinted cottonseeds. Seeds of the cultivar 7MH from the 98/99 season of Morada Nova-CE were divided into two samples. Two assays were done: inthe first, seeds were delinted with sulfuric acid (98%), for three minutes, being later washed in current water, while in the second, seeds were maintained with linter. Both samples were put to germinate on towel paper, cotton cloth and sand substrates, on fixed temperatures at 25ºC, 30ºC and alternated temperatures of 20-30ºC (20ºC/16h and 30ºC/8h). For each treatment, 400 seeds were used, being eight sub-samples of 50 seeds for paper and cloth substrates. The analysis were done in a seven days interval, being the first counting done at the fourth day and the final at the seventh day after the sowing. Two experiments were done to evaluate linted and delinted seeds, using the completely randomized design, with four replications, in a 3x3 factorial scheme. One concluded that for delinted seeds the germination test must be conducted on cloth cotton or paper towel substrate, atfixed temperature of 25ºC or 30ºC or alternated of 20-30ºC; for linted seeds, the best was cloth at alternated temperature of 20-30ºC.