The purpose of this work was to verify soil respiration kinetics in two sites in the semi-arid region of Paraíba, Northeast of Brazil. The first was a Mimosa hostilis Benth (jurema preta) colonized site, and the other was a degraded area without vegetation. Soil respiration was estimated every hour during a period of 12 hrs. Absorption of the liberated soil CO2 was obtained using a KOH 0.5 N solution. The amount of absorbed CO2 was determined through titration with a HCl 0.1 N solution. Temperature was measured at the surface and 10 cm deep in the soil in both areas. It was observed that the highest level of microbial activity, at the jurema preta site, occurred from 10:00 to 12:00 o¿clock AM. The lowest level of microbial activity was observed when temperature reached 50 oC. In the degraded area, microbial activity reached a maximum at 14:00 o¿clock PM due to the reduction of soil temperature.

Objetivou nesta pesquisa testar o efeito da poda de topo no rebaixamento da copa e poda da saia na recuperação da tangerineira 'Ponkan' com 12 anos de idade, altura de 4 metros, espaçadas de 6 x 4 m e enxertadas sobre limoeiro 'Cravo'. O experimento foi conduzido na Fazenda Vito Crincoli localizada no município de Perdões, MG. O delineamento experimental utilizado foi em blocos ao acaso, em esquema fatorial 4 x 2, sendo poda do topo (sem poda, poda a 3,0; 2,5 e 2,0m) e poda da saia (sem e com a poda) com quatro repetições. A parcelaútil foi constituída de três plantas. As podas drásticas de topo prejudicaram a primeira produção, contudo a partir do segundo ano da poda, as plantas apresentaram boa recuperação. Essa afirmativa foi confirmada na terceira colheita, quando os diferentes tipos de podas do topo não se diferenciaram na produtividade, sendo que o tratamento com poda da saia foi superior ao sem poda. Os diferentes tipos de poda não prejudicaram a qualidade de frutos de tangerineira 'Ponkan' nas três safras subsequente as podas. Após o terceiro ano as plantas que sofreram podas mais severas produziram frutos com peso superiores, demonstrando a viabilidade da poda na recuperação da qualidade dos frutos.

This research had as objective determination the floristic composition and some parameters phytosociological of the herbaceous vegetation of caatinga. The studied area is located in the located in the experiment station of UFPB, in the county of São João do Cariri, Paraíba, Brazil. Three caatinga physionomy were selected where were plots fixed of 10mx10m, an open one and another closed, containing 5 plots of 1m x1m total of 30m². Being a represented by the covering vegetable less conserved (Area I), other constituted by an area in intermediate apprenticeship of conservation (Area II), and the third area being represented by the covering vegetable more conserved (Area III). The herbaceous flora was represented by 31 genera, 40 species and 21 families with 3.091 ind.m² distributed in the three areas. The areas II and III presented larger wealth and diversity, expresses so much for the number of families as of identified species. The families, Convolvulaceae, Euphorbiaceae and Fabaceae presented larger number of species in the open and closed plots. Aristida adscensionis, (area I and II) and Cyperus uncinulatus (area III) the species that presented were larger value of importance in the closed and open plots were.

The occurrence of Spodoptera eridania (Cremer, 1782), Spodoptera dolichus (Fabricius, 1794) and Spodoptera cosmioidess (Walker) is registered for the first time attacking Crotalaria spp. in Rio Largo country (12°40' S, 39°06' W, 127 m de altitude), Alagoas State, Brazil.

Foliar nutrient contents are evaluated in several fruit trees with many objectives. Leaf analysis constitutes a way of evaluating the nutritional requirements of crops. Due to the positive impact that fertilizers have on crop yields, researchers frequently try to evaluate the correlations between yield and foliar nutrient contents. This work's objective was to present fruit yields from the 4th to the 6th cropping seasons, evaluate foliar nutrient contents (on the 5th cropping season), and estimate the correlations between these two groups of traits for 20 half-sibling custard apple tree progenies. The progenies were evaluated in a random block design with five replicates and four plants per plot. One hundred leaves were collected from the middle third of the canopy (in height) of each of four plants in each plot. The leaves were collected haphazardly, i.e., in a random manner, but without using a drawing mechanism. In the analysis of variance, the nutrient concentrations in the leaves from plants of each plot were represented by the average of four plants in the plot. Fruit yield in the various progenies did not depend on cropping season; progeny A4 was the most productive. No Spearman correlation was found between leaf nutrient concentrations and fruit yield. Increased nutrient concentrations in the leaves were progeny-dependent, i.e., with regard to Na (progenies FE5 and JG1), Ca (progeny A4), Mg (progeny SM7), N (progeny A3), P (progeny M), and K contents (progeny JG3). Spearman's correlation was negative between Na-Mg, Na-Ca, and Mg-P contents, and positive between Mg-Ca and N-K contents.

Objective of this study quality of lettuce cultivars under saline stress, in an experiment carried out in a greenhouse. The experiment was carried out in a completely randomized design, in scheme factorial 5 x 5, with three repetitions. The treatments were five levels of salinity of irrigation water (0.5; 1.5; 2.5; 3.5 and 4.5 dS m-1) and five lettuce cultivars (Mônica SF31, Grandes Lagos 659, Veneranda, Folha Roxa Quatro Estações e Stella). The quality characteristics evaluated in the lettuce leaves were: pH, total soluble solids (TSS), titrable total acidity (TTA) and vitamin C. The analysis of the results allowed concluding that the interaction between the factors salinity and cultivars was significant. The parameters of quality were significantly affected by salinity, however, the intensity of this effect varied with the cultivar used.

The maniçoba (Manihot glaziovii) owns good qualities as forage for the herds. The goal of this work was to evaluate forms for superation of numbness in maniçoba seeds. The research was developed in the Labotatório de Sementes-CCA/UFPB. It was used delineation entirely casualised, with four repetitions of 25 seeds. The treatments were: witness (without treatment) - escarification mechanical (SANDPAPER) - T2; escarification mechanical + immersion in water for 24 hours (SANDPAPER+24h) - T3; escarification mechanical + immersion in water for 48 hours (SANDPAPER+48h) - T4; immersion in hot water to 80ºC for 2' (80th+2min)- T5; immersion in hot water to 90ºC for 2' (90th+2min) - T6; immersion in hot water to 100ºC for 2' (100th+2min) - T7. The seeds, after treated, were sown in plastic arts trays contend sand and done daily countings for IVE's Determination, emergency first counting and percentage. The comparison of the averages was by Tukey's Test to 5% of probability. That the treatments T2 was observed and T3 were the ones that obtained best results of Emergency Velocity Indice (IVE), not differentiating to each other, however, in the treatments T5, T6 and T7 the emergency was null. For the first-rate results counting the treatment T3 was what it obtained better answer. Already for the results of emergency percentage T2 was what it introduced better result, ending up introducing 70% of emergency, followed by the treatments T3, T4, T1 respectively.

With the objective of evaluating the growth of three cultivates of carrot, it was done an experiment, from June until September, 2006, in the Vegetable garden of the "Departamento de Ciências Vegetais" of UFERSA, Mossoró-RN. This work was delineated in factorial scheme 8x3 in randomized blocks, with four repetitions. The first factor constituted by the times of collections of plants was: 7, 14, 21, 28, 35, 42, 49 and 56 days after polish, and the second for the cultivars: Brasília, Alvorada and Esplanada. The used spacing was 20cm among arrays and 4cm among plants. The characteristics evaluates were: number of leaves; dry mass root, leaves and total, foliate area, foliate area index (FAI), foliate area reason( FAR), relation part air/root and for the rates of relative growth (RRG) and absolute (RAG). The number of leaves, the foliate area, the dry mass root, leaves and total, RAG and FAI increased while FAR, relation part air/root and RRG refused, in the experimental period, for all the cultivates evaluated. The cultivates presented similar behavior with the relation to the characteristics: number of leaves, foliate area, dry mass leaves FAI, RRG and RAG. The mass accumulation of dry mass root it went superior for cultivars Alvorada and Brasília in relation to the Esplanada, for occasion of the harvest, in the 56 days after polish.

In sight of scarcity of references and information on the atemóia, this work considered to evaluate some chemical and physical analyses in intention to characterize two maturation stages. The used fruits in the experiment had been gotten in the Agropólo Mossoró-Assú, in the state of the Great River of the North. For this, the following analyses had been carried through: length and diameter of the fruit, total firmness of the pulp, soluble solids, pH, titulável total acidity and vitamin level C total. Differences between stadiums of maturation with degradation of the cellular components and the reserves of the fruits had been observed, thus reducing the firmness of the pulp and liberating simple sugars, respectively. It occurred increment in the acidity and consequence decrease in the value of pH. The vitamin C level didn't suffer significant alterations between such stages.

The latent infections represent serious problems for exportation of the fruits. Nevertheless, the number of products registered for postharvest treatment of melon is reduced. In view of that, was evaluated the efficiency of three pesticides thiabendazole, azoxystrobin and imazalil utilized, in the commercial doses of 194g, 8g and 100g, a.i. /100 l, respectively, in storage conditions at ambient temperature in the control of faulness postharvest caused for Alternaria alternata. The effect of pesticides on the mycelial growth, sporulation and germination of the fungi was evaluated, as well as the efficiency of the pesticides in the control of the fungi in melons. After the immersion of fruits in the fungicidal solution, discs of 5mm of PDA medium with the fungi structures were inoculated. After, four fruits were put in each cartoon package and storaged for 36 hours in a humid chamber. After that, the fruits were taken out of the humid chamber and storaged at ambient temperature. The Imazalil has inhibited 100% of the mycelial growth and sporulation of A. alternata. Although the azoxystrobin only reduced 36% of the mycelial growth, when compared with the standard sample, it shows efficiency related to sporulation. The Thiabendazole was also efficient to reduce the mycelial growth. However, it had not the same efficiency related to sporulation. All pesticides researched were efficient in the control 'in vitro', but they did not show any efficiency in the control of fungi in fruits storaged at ambient temperature.