The objective of that work was to evaluate the influence of different soil mulching and doses of organic compost in the culture of the rocket. The experimental design was used in randomized blocks, in splitplot arrangement with four replications. The plot corresponded to the soil mulching (no-tillage with living mulch of Arachis pintoi, living mulch of native weed, straw mulch of native weed and conventional tillage without mulching). The plots represent the doses of organic compost (10, 20 and 30 t ha-1 in the dry compost). The variables analyzed were yield, commercial fresh matter, and dry matter of the aerial part. The dose of 30 t ha-1 provided the largest yield values and commercial fresh mass for the conventional system and straw mulch. The dose 20.49 t ha-1 increased yield and commercial fresh mass for A. pintoi mulch. The dose 20.85 t ha-1 showed greater increase in yield and commercial fresh mass for the live native weed. The tillage and straw mulch presented higher yield values for all the studied doses. The dose of 23.1 t ha-1 it promoted the largest dry mass of the aerial part. The tillage and no-tillage with straw mulch it contributed with the largest dry matter of the aerial part.

Phylogeography has become a powerful approach for elucidating contemporary geographical patterns of evolutionary subdivision within species and species complexes. The aim of this paper was to evaluate the extracted quality of DNA and amplification of noncoding chloroplast DNA for phylogeography studies in Ficus bonijesulapens. The comparative analysis of protocol DNA extraction was based in the CTAB method and protocol from Mogg and Bond. DNA samples were assessed for successful PCR amplification of universal primers for the amplification of noncoding regions of cpDNA. Amplified DNA was separated by electrophoresis, stained with ethidium bromide and photographed under UV light. The protocol Moog e Bond produced the best DNA quality. This method will be used because it produces a high quality DNA in a short time and is less expensive. The primers HA, SG, BF, Q16, F32, FV, DT, CS and JA provided the strongest support for the inferred phylogeography, genetic diversity centers and for successful management in tree-conservation programmes.

Lettuce has highlight as an important crop for human consumption, to having good flavor and important nutritional characteristics and potassium is one of the main nutrients that crop. This work aimed to evaluate the influence of potassium in morphological and physiological lettuce responses in South of Tocantins State. The experimental design was randomized block in factorial scheme of 4 x 6 with three replications. Four levels were evaluated of K2O: 0; 100; 200 and 300 kg ha-1 in six development stages: 15; 22; 29; 36; 43 and 50 days after emergency. Was determine the specific leaf area, net assimilation rate, relative growth rate and abso-lute growth rate, as well as the leaf, stem and root weight. During the duration of the experiment occurred high temperatures that caused a physiological disorder known as tipburn, which compromises calcium uptake by the plant. The potassium levels did not influence the morphological and physiological responses of lettuce as well did not significant differences among levels for leaf, stem and root weight. The partition of assimilates in the plants was influenced by crop management whit significant variation among evaluation times.

This work aimed to evaluate the influence of the substrate and the level of moisture on the germination of 'pau-de-balsa'. Before installation of the germination test, seeds were immersed in hot water at 80 °C until cooling to overcome dormancy. We evaluated the substrate sand and vermiculite, moistened with water volumes equivalent to 60%, 70%, 80% and 90% of the capacity to retain water. The experimental design used was completely randomized in a 2 x 4 factorial with four replicates of 20 seeds. The effects of treatments were compared for germination percentage, speed index and average time of germination. The seeds had higher germination in sand substrate, and the moisture level of the substrate does not affect the variables analyzed.

This work aimed to evaluate the effect of cut height on jurema-preta control. Thus, two trials were carried out, one in September 15th and other in December 15th of 1997. The experimental area had 1,400 m². Treatments were the height cuts of 25; 50; 75 and 100 cm from the soil. Evaluations were done when more than half of plants were showing 50% of their regrowth with a diameter of 0.7 cm. The experimental design was in randomized blocks with split-plot, being the height cut the parcel and the cut the sub-parcel. In the first trial and at the end of the 3rd cut, the higher mortality of 84.6% was found among plants cut at 75 cm and the higher number of regrowth was observed in plants cut at 100 cm, but the stem diameter was not affected by treatments. In the second trial and at the end of the 3rd cut, the higher mortality of 50% was found among plants cut at 100 cm and the other variables were not affected by cut height. The control of jurema-preta may be done in September, cutting the plants at 75 or 100 cm from the soil and always cutting the regrowth plants when they reach 0.7 cm of diameter. The jurema-preta control by standardization cut in December was inefficient regardless the cut height.

The aim of this study was to evaluate silicon (Si) and two phosphorus (P) extraction methods in "Latossolos" under corn and sorghum. The experiments were conducted in green-house, in a completely randomized, with corn for the 5x2x2 factorial arrangement, consisting of five P rates (0, 96, 192, 288 and 480 mg dm-3) in the absence and the presence of 300 mg dm-3 of slag in two "Latossolos" and four replicates, while for sorghum the experimental design was 5x2, and is used only one soil. The experimental plots were subjected to two incubation periods, the first with slag (only half of the plot) and then with lime. In the first experiment two plants were cultivated corn pot for 45 days and then ten plants of sorghum for 60. After the experiments took place the collection of plants being evaluated for plant height, stem diameter and dry weight of maize shoots and just shoot dry matter of sorghum, the levels of Si and P in samples soil and plants. The medium texture soil showed better correlations of Si and P. For the Olsen P method as both the Mehlich 1 had good correlation. Sorghum showed higher correlation coefficients than corn.

The objective of the present study was to evaluate the effects of different pre-treatments on the germination of the seeds as well as the emergence velocity of the seedlings of Erythrina velutina and Erythrina falcata. The treatments utilized for the evaluation of germination were intact seeds (control); mechanical scarification with sandpaper number 120 in the opposite side of the embryo; and immersion in water at room temperature for 6, 12, 24 and 48 hours. Four replications of 25 seeds each were used per treatment and the experimental design was completely randomized, and the comparison among the averages was made using the Tukey test at 5% of probability. The percentage of germination, the emergence velocity index and the relative frequency of germination were calculated 31 days after sowing. For both species, better percentages of germination and values of emergence velocity were obtained with the mechanical scarification of seeds. That treatment was efficient in the uniformization and anticipation of the germination process. However, the tests done with seed immersion in water at room temperature for up to 48 hours do not increase the percentage of germination of E. velutina and E. falcata seeds.

This study aimed to evaluate the influence of S. platensis as a food supplement for Nile tilapia post-larvae. Two trials was running. In the first, was used two treatments, one offered freshwater microalgae (green water) and other offered microalga S. platensis. In the second trial, were evaluated the effect of without copepods, administration of copepods alone and copepods enriched with S. platensis. Throughout the study, all animals were fed diets with masculinizing hormone 17-K-methyl-testosterone. It was evaluated the growth in weight and length, the survival rate and the rate of sex reversal of tilapia (mean +,- SD). In the first trial, the fish that received the S. platensis and receiving freshwater microalgae showed as result, 0.21 +,- 0.042 g; 2.50 +,- 0.091 cm; 97.5 ± 1,00% and 0.11 +,- 0.022 g; 1.91 +,- 0.419 cm; 98.33 +,- 0.70%, respectively. In the second trial, when the copepods were utilized, with and without S. platensis, the post-larvae as result, 0.221 ± 0.008 g; 2.70 ± 0.070 cm; 86.67 +,- 1.03% and 0.211 +,- 0.014 g; 2.56 ± 0.121 cm; 77.50 +,- 1.33%, respectively. The animals that received only commercial had as result, 0.190 +,- 0.008 g; 2.22 +,- 0.215 cm and 79.17 +,-0.21%. Using S. platensis resulted in better growth in weight and length, but did not affect survival and rates of sex reversal Nile tilapia post-larvae of exposed to natural food.

Macambira is a bromélia used in the alimentation of man and domestic animals on Northeast of Brazilian, especially in times of drought. The study was conducted to evaluate at identifying breaking dormancy methods and verifying how temperature and light can affect germination of its seeds. In the first experiment, the seeds were treated the following treatments: immersion in acetone, in alcohol, to eter, hot water, wash in running water, dry cold and dry heat, aiming at breaking dormancy and control. Were determinate the percentage of germination, first count of germination, index of velocity of germination and the mean time of germination. In the second experiment, after treatment of immersion in acetone during 60 minutes, the seeds were germinated under the following conditions: continued light and 25 ºC constant; continued light and 30 ºC constant; continued light and 35 ºC constant; continued light and temperatures (35 ºC/8 h and 20 ºC/16 h); continued dark and 25 ºC constant; continued dark and 30 ºC constant; continued dark and 35 ºC constant; continued dark and temperatures (35 ºC/8 h and 20 ºC/16 h); alternation of light (dark/16 h and light/8 h) and temperature of 25 ºC constant; alternation of light (dark/16 h and light/8 h) and temperature of 30 ºC onstant; alternation of light (dark/16 h and light/8 h) and temperature of 35 ºC constant; alternation of light and temperature (dark/20 ºC/16 h and light/35 ºC/8 h) and alternation of light and temperature (dark/25 ºC/16 h and light/35 ºC/8 h). It follows that the immersion in acetone during 60 minutes was the treatment more efficient to promote the of vigor and germination of seeds. The seeds do not germinate in the light absence, behaving as fotoblásticas positive.

The purpose of this research was to make a floristic survey of the shrubby-arboreous stratum in three contiguous areas of Caatinga in the Cariri of Paraiba. The survey was accomplished in the "Estação Experimental Bacia Escola/UFPB", municipality of São João do Cariri, PB Brazilian Northeast. The experiment consisted of three areas of 3.2 ha, where three parallel transects had been established, in a distance of 20 m from each other, and there were marked ten parcels with equidistant systematic distribution (10 m x 10 m), having been sampled 30 parcels from each area. The floristic survey was carried through by the method of parcels. There was fulfilled a grouping analysis using the index of similarity of Jaccard. The number of parcels showed was enough to reflect the plantdiversity of the studied places; the families with highest number of species in the arboreous-shrubby stratum were Cactaceae and Euphorbiaceae; the species that had been common in the three areas, , were: Aspidosperma pyrifolium, Croton blanchetianus, Poincianella pyramidalis, Jatropha mollisssima, Malva sp., Pilosocereus gounellei, Spondias tuberosa and Opuntia palmadora. The arboreous habitat presented seven species, being higher to the shrubby component that was presented with five species. The more conspicuous arboreous elements had been: Poincianella pyramidalis (Caesalpiniaceae) and Aspidosperma pyrifolium (Apocynaceae). The most important shrubs were: Croton blanchetianus and Jatropha mollisssima (Euphorbiaceae). The analysis made by the index of floristic similarity indicated that the similarity was considered high by the three area, because they presented a Jaccard index higher than 0.25.