The cladodes size is an important feature when selecting cuttings for red pitaya (Hylocereus undatus (Haw.) Britton & Rose) seedling production. The paper was carried out with the aim of evaluating different sizes of cladodes in the production of dragon fruit seedlings. The experimental design was randomized blocks with five treatments, which were the cladodes sizes: 5; 10; 15; 20 and 25 cm, with four replicates and four cladodes per plot. After 80 days of the experiment, there were evaluated: number of shoots per plant, percentage of rooting, length of greater root and dry weight of roots. The size of cladodes directly influences the production of seedlings. The lengths of cladodes from 15 to 25 cm are the most suitable for the dragon fruit seedlings.

In order to evaluated the impact of the high salinity reject brine from reverse osmosis desalination on hydroponics lettuce cultivated in greenhouse an investigation was carried out in Mossoro, Northeast of Brazil (5º11'S, 37º20'O and 18m above sea). Two lettuce cultivars ('Verônica' and 'Babá de verão') were cultivated with a basic nutrient solution with 1.1 dS m-1 (control) during the crop cycle (1-28 days after transplanting - DAT) - T0 and with basic nutrient solution containing 50% of the reject water from desalinization with 4.8 dS m-1 exposed during 1-7, 21-28, 7-14 e 1-28 DAT (T1, T2, T3 and T4, respectively). The addition of 50% of brine reject from desalination into the hydroponic nutrient solution allows grow only 'Verônica' lettuce with no reduction in fresh biomass. This lettuce cultivar shows to be more tolerant to salinity for all exposure time with reject brine in the nutrition solution, despite the fact that 'Babá de Verão' cultivar is more productive.

Atrazine is a herbicide applied to a number of important crops, but litle has been done to study the susceptibility of species like Digitaria horizontalis to such herbicide. This work was carried out to evaluate the effect of the stage of development of Digitaria horizontalis at spraying on the suppression imposed by atrazine. The experiment was conducted in 10 dm-3 pots, under greenhouse conditions, and the experimental units were disposed in a completely randomized design, in a factorial scheme 5x3, with four replicates. Treatments were composed by Five rates of atrazine (0; 0.5; 1.5; 2.5 and 4.0 kg ha-1), applied in three stages of D. horizontalis development (two leaves, four leaves and one-two tillers). Applications accomplished in later stages of development were inefficient in controlling this species, despite causing significant reductions of weed shoot and root dry mass and plant height. For applications at two leaves stage, a maximum of 60% control was achieved by using 4.0 kg ha-1 of atrazine, indicating the lack of efficiency of this herbicide in controlling this species.

The preliminary investigation of chemical constituents of a plant allows the prior knowledge of the extract and indicates the nature of the present substances. The aim of this paper was to detect the absence or presence of appreciable amounts of various chemical constituents in extracts of jurubeba [Solanum paniculatum Linnaeus (1762)], capim santo [Cymbopogon citratus Stapf (1906)], batata de purga [Operculina hamiltonii (G. DON) D.F. Austin & Staples (1983)] and melão de são caetano [Momordica charantia Linnaeus (1763)], which has been indicated as alternative treatment against gastrintestinal helmintiasis of small ruminants. The jurubeba was collected in the city of Teixeira - PB. The capim santo, the batata de purga and the melão de são caetano were collected at the Centro de Saúde e Tecnologia Rural/UFCG, Patos - PB, in august and september of 2008. After, was realized the identification of the indicated shares to the ethnopharmacology study, deposited in the Herbário Caririense Dárdano de Andrade - Lima of the Universidade Regional do Cariri-URCA. The acquisition of the extract and phytochemical study followed the methodology described by Matos (1997). To obtain the extract was used the dust of the shares collected from each plant and as solvent ethanol PA. Four tests (phenols and tannins; anthocyanins, anthocyanidins and flavonoids; leucoanthocyanidins, catechins and flavanones; and alkaloids.) were conducted for the exploration of hydroalcoholical constituents. In the chemical assay were concluded that the ethanol extracts of the four plants with compounds such as tannins and catechins, and absence of phenols, anthocyanins and proanthocyanidins.

The bit of cane sugar, Diatraea saccharalis (Fabricius, 1794), (Lepidoptera: Crambidae), is the main plague of sugar cane in Brazil. The objective of this study was to evaluate the intensity of infestation in five varieties of commercially sugar cane. The experiment was conducted at Parnaíba Valley Company (COMVAP), that belongs to the Olho D'água Group, located in the city of União - Pi (latitude 04° 51' 08" S; longitude 42° 52' 59" W). Gallo methodology was used to evaluate the the intensity of infestation. It is calculated by: II% = 100 x blocked internodes / total number of internodes. The intensity of infestation of all sorts was considered very low. The varieties SP73-2577, SP83-2847, SP81-3250, SP79-1011 and RB92-579 did not present infestation, using the no-parametric test of Kruskal - Wallis, meaningful statistic differences among them. All varieties showed similar intensity of infestation and may be recommended respecting other desired characteristics.

This paper aimed to evaluated the effect of the use of potassium nitrate on the reduction of stress on the melon plants exposed to excess salt in the irrigation water. The experiment was carried out at the Centro de Ciências e Tecnologia Agroalimentar (CCTA/UFCG) Pombal-PB, from 19/09/2009 to 20/10/2009, using the hybrid melon 'Hales Best Jumbo'. The treatments consisted of two levels of of salinity of the irrigation water (0.3 and 5.0 dS m-1) and rates of N in the form of potassium nitrate (5.5; 6.25; 7.0 and 8.5g per plant). The experimental design was randomized blocks, on the factorial scheme 2x4, with four replications. The highest rates of photosynthesis, stomatic conductivity, transpiration, leaf area, total dry mass and the fruit yield per plant were observed on melon plants irrigated with low salinity water (0.3 dS m-1) compared to the ones with the high saline water (5.0 dS m-1), and on rates of N between 6.10 and 7.8g of N per plant for both levels of salinity. The supply of N in the form of potassium nitrate was effective on reducing the melon plant the stressing effect caused by the salinity of the irrigation water up to the rate of 6.85g of N per plant. On absolute terms we can affirm that the best performance of the melon plant was achieved with the rate of 7.0g of N per plan when irrigated with normal water and 6.25 of N per plant when irrigated with saline water.

To evaluate the effect of the temporary replacement of shrimp ration (RC) by chicken ration (RF) in the culture of Litopenaeus vannamei shrimp, juvenils (1.07 ± 0.26 g), were cultivated (52/m2) for 30 days in 50 L boxes, with constant aeration, 0% of water exchange and fed with 10% of its biomass/day at 08:00 and 16:00 h, according to the treatments: (1) RC; (2) 1 week RC + 1 week RF, alternate; (3) RF and (4) 1 day RF + 1 day RC, alternate; with 5 repetitions each. There was no difference (P <0.05) in the weight of shrimp on the basis of treatments applied at the beginning (Kruskal-Wallis, P = 0003), 15 days (Kruskal-Wallis, P = 0.98) and at 30 days (Kruskal-Wallis, P = 0.07) to experiment. The Specific Growth Rate (rm ANOVA, P = 0.28) and survival (Friedman, P = 0,34 the animals were significantly similar, indicating that these parameters were not affected by treatments, with the possible replacement of shrimp ration by chicken ration, as a measure of containment of expenditure, for short intervals of time. Studies are needed to validate these results in earth ponds.

This experiment was carried through with objective to evaluate bromatologicament the aerial part and the root of 11 (eleven) to cultivate of cassava, thus determining information for the animal consumption. The experiment was developed in the Experimental Station "Felipe Camarão" pertaining to Empresa de Pesquisa Agropecuária do Rio Grande do Norte S/A - EMPARN, situated in São Gonçalo do Amarante - RN. The following variable had been evaluated: Dry substance, mineral substance, organic substance and rude protein, of the root and aerial part and fiber in acid detergent, fiber in neutral detergent, etéreo extract, insoluble nitrogen in acid detergent, insoluble protein in acid detergent,, total carbohidrates and not-fiber carbohidrates only of the aerial part of the cassava. The used experimental delineation block-type complete was casualizados, with four repetitions. The experimental treatments had been the following ones to cultivate of cassava, proceeding from the Experimental Stations of da EMEPA, EMBRAPA Mandioca e Fruticultura, EMPARN: Cigana Preta, Surrão, Pão da Tarde, Manteiga, Salangó, Osso Duro, Amazonas, Eucalipto, Monge, Bahia Preta e Bravo Preto. It concludes that we must limit the consumption of the aerial part of any to cultivate of the cassava the what concerns amount of indigestível fiber. On the other hand, to cultivate studied them present an excellent Rude Protein concentration. To cultivate Brave if it detaches for presenting one high amount of protein (12.88%).

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 present work objectified to detect tendencies of long period in the annual averages of the air temperature. We analyzed minimum, mean, and maximum temperature, absolute minimum, and absolute maximum. Twenty-four meteorological stations on the Northern Northeast (Ceará, Rio Grande do Norte, Paraíba and Pernambuco) were used. We used the historical series from 1961 to 1990. To identify the tendencies, we used the analysis of lineal regression analysis. The Student's t-test was used to verify the statistical of the coefficients of lineal regression. We observed an increase of the minimum, mean, maximum temperature, and absolute minimum. The absolute maximum temperature didn't present significant tendencies of increase nor of decrease. We conclude that has had a decrease of the annual thermal amplitude of the temperature on the Northern Northeast, mainly, due to the increase of the night temperature.