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Calheiros A.S.,Instituto Federal Of Alagoas | Junior M.A.L.,University of Pernambuco | Santos M.V.F.,University of Pernambuco | Lyra M.C.C.P.,Instituto Agronomico Of Pernambuco
Revista Brasileira de Ciencia do Solo | Year: 2015

Biological N fixation in forage legumes is an important alternative to reduce pasture degradation, and is strongly influenced by the inoculant symbiotic capability. This paper evaluates the effectiveness of Calopo (Calopogonium mucunoides) rhizobial isolated from soil under three vegetation covers of an Argissolo Vermelho-Amarelo of the Dry Forest Zone of Pernambuco. An experiment was conducted evaluating 25 isolates, aside from 5 uninoculated controls with 0; 309; 60; 90 and 120 kg ha-1 N, and a treatment inoculated with the SEMIA 6152 strain. The first cut was performed 45 days after inoculation and a second and third cut after 45-day-intervals. Shoot N content was quantified at all cuts. Shoot dry mass was affected by N rates at all cuts. Shoot dry mass increased from the first to the second cut in inoculated plants. There was no difference between rhizobial isolates from the different plant covers for any of the variables. Most variables were significantly and positively correlated. © 2015, Revista Brasileira de Ciencia do Solo. All rights reserved.

Coitinho R.L.B.C.,Instituto Agronomico Of Pernambuco | de Oliveira J.V.,University of Pernambuco | Gondim Jr. M.G.C.,University of Pernambuco | da Camara C.A.G.,University of Pernambuco
Ciencia e Agrotecnologia | Year: 2011

The Sitophilus zeamais species is a major pest of stored maize in Brazil. The control is made, usually, using measures of hygiene and cleanliness, synthetic insecticid es and fumigant protectors. The search for less toxic products, biodegradable and safe from an ecological point of view is very well accepted by society. The objective of this study was to test the toxicity by contact and ingestion and fumigant of essential oils and eugenol natural organic compound for adults of S. zeamais. The values of LC50 in oil from leaves of Piper hispidinervum, Eugenia uniflora, Cinnamomum zeylanicum, P. marginatum, Schinus terebinthifolius, Melaleuca leucadendron, green fruits of S. terebinthifolius and eugenol compound in tests of contact and ingestion were estimated at 1.0; 11.6, 14.2, 21.1, 57.7, 75.8, 98.8 and 14.8 L/40 g maize, respectively. The toxicity ratios (TR) ranged from 1.3 to 98.8. In the fumigation of adults, the lethal concentrations ranged from 0.53 to 94.7 L/L air, in the following order of toxicity: P. hispidinervum > P. aduncum > S. terebinthifolius > green fruits of S. terebinthifolius > P. marginatum > eugenol, and the TR ranged from 2.0 to 178.7.

Tapajos S.J.,University of Pernambuco | Lira R.,University of Pernambuco | Silva-Torres C.S.A.,University of Pernambuco | Torres J.B.,University of Pernambuco | Coitinho R.L.C.B.,Instituto Agronomico Of Pernambuco
Biological Control | Year: 2016

Mealybugs (Hemiptera: Pseudococcidae) have spread throughout subtropical and tropical regions, causing severe losses to crop production that have prompted much interest in discovering effective biological agents against these pests. The Brazilian indigenous lacewing (Neuroptera: Chrysopidae) species Chrysoperla externa (Hagen) and Ceraeochrysa everes (Banks) were studied against two exotic mealybug species, Ferrisia dasylirii (Cockerell) and Pseudococcus jackbeardsleyi Gimpel & Miller. To assess the relative potential of these lacewing species as control agents against these two pests, we confined 1st-, 2nd-, and 3rd-instar lacewing larvae with 2nd- and 3rd-instar nymphs and adult female mealybugs to evaluate development, survival, reproduction and predation rate. Lacewing larvae at 2nd- and 3rd-instar preyed successfully on mealybugs of all ages, and second instar mealybug nymphs supported successful development of lacewing larvae irrespective of the predators' age. However, 1st-instar lacewing larvae either failed to complete development or showed lower performance when fed only 3rd-instar or adult female of mealybugs of either species. Comparing the lacewing species, Ce. everes tended to produce more eggs, but showed delayed development and lower egg viability as compared to Ch. externa. Furthermore, in every case in which a significant difference in predation rate was detected, it was always superior for Ch. externa. Further studies to assess the establishment of these species and other lacewing species associated with these introduced mealybugs are reasonable to provide sustainable biological control. © 2016.

da Silva E.F.,Federal Rural University of Pernambuco | Tabosa J.N.,Instituto Agronomico Of Pernambuco
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2010

Twelve upland rice genotypes were evaluated in the 'Zona da Mata' of Pernambuco State regarding characteristics of agronomical importance. The experimental design was randomized block with four replications and plots composed of 5 rows of 4 m length and 0.5 m spacing. The experiments were carried out from April to August during the agricultural year 2006 at the Palmares and Vitoria de Santo Antão municipalities. Amongst the evaluated characteristics there were significant differences among genotypes for plant height, lodging, flowering and maturation cycle, number of tillers per plant, length of panicle, 1000-grain weight and grain yield. Genotype versus environment interaction was significant for the characteristics of plant height, flowering, cycle and percentage of spikelet sterility. The genotypes Bonança, BRA 1506, CNAs 9045 and BRSMG curinga showed better performance on plant height, lodging, flowering and maturation cycles besides good tillering per plant and average yield. Therefore, these genotypes bring a good perspective for cultivation in the region during the period of April to July.

de Paiva-Maia E.,Aquarium Aquicultura | Alves-Modesto G.,Aquarium Aquicultura | Otavio-Brito L.,Instituto Agronomico Of Pernambuco | Olivera A.,University of Pernambuco | Vasconcelos-Gesteira T.C.,Federal University of Ceara
Latin American Journal of Aquatic Research | Year: 2013

The aim of this study was to evaluate the effect of a commercial probiotic on the bacterial and phytoplankton concentration in intensive shrimp farming (Litopenaeus vannamei) with a recirculation system, for one culture period in Rio Grande do Norte, Brazil. Ponds, with mean area of 2.6 ha, were stocked with a density of 98 shrimp m-2. A commercial probiotic was prepared following the manufacture's specifications and sprayed on the surface of the ponds seven days prior to stocking and then on a weekly basis until harvest. The same procedures were used with all treatments (control and probiotic), with regard to feeding, liming, fertilization, use of molasses and monitoring of water quality. Field data were analyzed using ANOVA, the Tukey test and Chi-square tests. No significant differences between treatments were found for water quality data, but treatment means showed significant differences for total heterotrophic bacteria in the sediment (5.181 ± 0.34x104 cfu g-1 and 5.749 ± 0.67x104 cfu g-1), total heterotrophic bacteria in surface water (4.514 ± 0.95x 104 cfu m L-1 and 4.136 ± 0.81x104 cfu m L-1) and positive sucrose in surface water (2.438 ± 0.72x104 cfu m L-1 and 2.203 ± 0.76x104 cfu m L-1), respectively, for the control and probiotic treatment. Significant differences were also observed throughout the weeks for total heterotrophic bacteria in the sediment, positive and negative sucrose in the sediment, total heterotrophic bacteria in surface and bottom water, and Pyrrophyta percentage values between 10 and 16 weeks. These results showed that the probiotic causes changes in the total heterotrophic bacteria in the sediment and percentage values of Pyrrophyta concentration, improving the environmental quality of the sediment and water in ponds with closed recirculation systems.

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