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Peixoto Henares M.N.,Centro Universitario Da Fundacao Educacional Of Barretos Unifeb | Peixoto Henares M.N.,Sao Paulo State University | Monteiro Camargo A.F.,Sao Paulo State University | Monteiro Camargo A.F.,Claro
Acta Limnologica Brasiliensia | Year: 2014

Aim: To evaluate the growth of Eichhornia crassipes (Mart.) Solms and Salvinia molesta Mitchell in tanks used for treating aquaculture effluent and compare the results with literature data in order to estimate the nutrients saturation point. Methods: An experiment with six rectangular fiberglass tanks were separated in two treatments, inflow and outflow (higher and lower nutrient concentration), and the two macrophytes above cited was carried out during 50 days. A floating quadrat with 0.25 m2 of E. crassipes and S. molesta at inflow and outflow of the tanks was collected weekly for fresh mass measurement. At the beginning and end of the experiment samples of macrophytes were oven-dried at 60 °C until constant weight to determine the dry mass. Dry mass of plants was estimated by a simple linear regression analysis between fresh mass and dry mass (DM). Results: The N and P concentrations were significantly higher (P<0.05) in the inflow (mean of 0.66 mg L–1 and 233.6 mg L–1, respectively) than in the outflow of the tanks (mean of 0.38 mg L–1 and 174.7 mg L–1, respectively). However, no significantly different plant growth was observed for either higher or lower concentration. For both higher and lower nutrient concentrations, the biomass gain for E. crassipes was, respectively, 428.5 and 402.7 g DM.m2. For S. molesta, biomass gain was 135.2 and 143.1 g DM.m2, in the higher and lower concentrations, respectively. Others studies reported high growth of E. crassipes and S. molesta in concentrations of nitrogen (0.14 – 0.18 mg L–1) and phosphorus (14.2 – 77.0 mg L–1) lower than this study. Conclusion: The comparison of E. crassipes and S. molesta growth in this study with others allow us to assume that the saturation point of E. crassipes should be 0.26 mg L–1 of nitrogen and 77 mg L–1 of phosphorus and for S. molesta below 0.19 mg L–1 of nitrogen and 15.1 mg L–1 of phosphorus. © Acta Limnologica Brasiliensia, 2014 Source


Farinelli R.,Centro Universitario Da Fundacao Educacional Of Barretos Unifeb | Lemos L.B.,Sao Paulo State University
Pesquisa Agropecuaria Tropical | Year: 2012

Nitrogen is the nutrient most required by the maize crop, being often the most limiting one to grain yield. This research aimed to evaluate maize response to yield, agronomic traits, and efficiency of nitrogen (N) use, in relation to nitrogen topdressing, under conventional and no-tillage systems, in an area where soil management systems have been studied for twenty years (1985- 2005), in the Universidade Estadual Paulista, in Botucatu, São Paulo State, Brazil. The experimental design was randomized blocks, in a split-plot arrangement, with four replications. The plots consisted of conventional and no-tillage systems and the subplots comprised topdressing nitrogen doses (0 kg ha -1, 40 kg ha -1, 80 kg ha -1, 120 kg ha -1, and 160 kg ha -1). The nitrogen topdressing promoted significant increases in maize agronomic and nutritional traits, with maximum grain yield obtained with 151 kg ha -1 of N. For the 90 kg ha -1 and 145 kg ha -1 nitrogen topdressing doses, the agronomic and recovery efficiency values were similar, when considered the conventional and no-tillage systems, respectively. The grain yield and maize agronomic and nutritional traits were not affected by soil management system. Source


Carraschi S.P.,Sao Paulo State University | Ikefuti C.V.,NEPEAM | Florencio T.,NEPEAM | da Cruz C.,Centro Universitario Da Fundacao Educacional Of Barretos Unifeb | Ranzani-Paiva M.J.T.,Institute Pesca Of Sao Paulo
Aquaculture | Year: 2014

The use of drugs in aquaculture is necessary to combat pathogens responsible for causing the high rate of mortality in fish farming, such as infection by ectoparasites. The aim of this research was to evaluate the efficacy: (A) of toltrazuril (TOL) treatment against Ichthyophthirius multifiliis, Trichodina heterodentata and Anacanthorus penilabiatus; (B) of thiamethoxam (TH), in treating fish infected by A. penilabiatus and (C) of enrofloxacin (ENR) and florfenicol (FFC) against Aeromonas sp. and Streptococcus sp. The drugs TOL and TH were administered in therapeutic baths while ENR and FFC were mixed with the fish food. The drug concentrations were adjusted according to the experimental conditions (laboratory, microcosm or mesocosm). The drug TOL presented a treatment efficacy rate of 100% against I. multifiliis in microcosm and T. heterodentata in mesocosm. Moreover, ENR presented an efficacy rate of 100% in treating fish infected by Aeromonas sp. and Streptococcus sp. in mesocosm. Finally, TH efficacy rate in controlling A. penilabiatus infection was 81.86% in mesocosm and FFC decreased the overall bacterial load in infected fish. Aeromonas sp. and Streptococcus sp. strains were found in the samples collected for microbiological analysis. In conclusion, TH presented a high efficacy in treating fish against A. penilabiatus infection while TOL was better in controlling T. heterodentata. The antibiotics used in mecoscosm condition presented potential to be used against bacterial infection in aquaculture. © 2013 Elsevier B.V. Source


Henares M.N.P.,Centro Universitario Da Fundacao Educacional Of Barretos Unifeb | Henares M.N.P.,Sao Paulo State University | Camargo A.F.M.,Sao Paulo State University | Camargo A.F.M.,Claro
Brazilian Journal of Biology | Year: 2014

The efficiency of a series of wetland colonized with Eichhornia crassipes and Salvinia molesta to treat the effluent of a giant river prawn (Macrobrachium rosenbergii) broodstock pond was evaluated in this study. The experimental design was completely randomized and was performed in 9 rectangular tanks (1.6 m3) with three treatments (constructed wetlands) and three replicates. The treatment types included: a wetland colonized with E. crassipes and S. molesta (EcSm) arranged sequentially, a wetland with E. crassipes only (Ec) and a wetland with S. molesta only (Sm). The means of suspended particulate material (SPM), total inorganic nitrogen (TIN), total Kjeldahl nitrogen (TKN), P-orthophosphate (PO4-P) and total phosphorus (TP) of the treated effluents were compared using ANOVA followed by Tukey’s test (P<0.05). The effluent treated in Ec and EcSm wetlands exhibited lower SPM concentrations. The Ec wetland reduced TIN, TKN, PO4-P and TP by 46.0, 43.7, 44.4 and 43.6%, respectively. In the EcSm wetland, the reduction of TIN (23.0%), TKN (33.7%) and PO4-P (26.7%) was similar to the Sm wetland (19.8% TIN, 30.9% TKN and 23.8% PO4-P). The Ec wetland was more efficient in treating pond effluent due likely to the higher root surface of E. crassipes, which forms an extensive area favorable to retention and adsorption of debris and absorption of nutrients. © 2014, Instituto Internacional de Ecologia. All rights reserved. Source


Henares M.N.P.,Sao Paulo State University | Henares M.N.P.,Centro Universitario Da Fundacao Educacional Of Barretos Unifeb | de Lima Preto B.,Sao Paulo State University | de Lima Preto B.,Instituto Federal do Espirito Santo IFES | And 3 more authors.
Aquaculture Research | Year: 2015

The effects of artificial substrate and night-time aeration on the culture of Macrobrachium amazonicum were evaluated in 12 ponds stocked with 45 prawns m-2. A completely randomized design in 2 × 2 factorial scheme with three replicates was used. The combination of factors resulted in four treatments: with substrate and aeration (SA), with substrate and without aeration (SWA), without substrate and with aeration (WSA) and without substrate and aeration (WSWA). The presence of substrate in SA and SWA treatments reduced suspended particles (seston) by ~17.3% and P-orthophosphate by ~50%. The use of aerator (WSA and SA treatments) significantly (P < 0.05) increased the concentration of dissolved oxygen, suspended particles and nutrients in the pond water. These results indicate that the effect of substrate on turbidity and total suspended solids (TSS) values is opposite to the effect of the aerator. The aerators in semi-intensive grow-out M. amazonicum farming lower water quality because they increased the amount of detritus and nutrients in the pond water. On the other hand, the use of artificial substrate reduces turbidity values, chlorophyll a, TSS and P-orthophosphate concentrations. Therefore, the combination of substrate addition and night-time aeration is not interesting because they have opposite effects. © 2013 John Wiley & Sons Ltd. Source

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