ResumoA avaliação da proporção ideal de concha calcária/brita em biofiltro no cultivo de pós-larvas de tilápia do Nilo foi o objetivo deste trabalho. O experimento foi realizado no Laboratório de Aquicultura e Ecologia Aquática da Universidade Federal dos Vales do Jequitinhonha e Mucuri -UFVJM, entre os dias 21 de julho a 3 de agosto de 2011. Pós-larvas de tilápia do Nilo na densidade de 13,3 pós-larvas/L foram cultivadas em aquários contendo biofiltros com 100% concha calcária; 70% concha calcária/30% brita; 50% concha calcária/50% brita; 30% concha calcária/70% brita; 10% concha calcária/90% brita; 100% brita e como controle, aquário sem biofiltro, em DIC, totalizando sete tratamentos com três repetições. A presença de concha calcária no biofiltro proporcionou melhores condições da água, quando comparado com os aquários sem biofiltro e com brita apenas, mantendo os parâmetros adequados para o cultivo de tilápia do Nilo. Apesar dos níveis de amônia estarem próximos ao limite superior desejado para o cultivo da espécie, eles não comprometeram o crescimento (comprimentos total e padrão, altura e peso). A proporção 30% de concha calcária e 70% de brita é recomendada como substrato de biofiltro, por apresentar a melhor taxa de nitrificação ao longo do experimento. Palavras-chave: biofiltração, larvicultura, nitrificação, resíduos nitrogenados, Oreochromis niloticus. AbstractThe evaluation of the optimal ratio of calcareous shell/gravel substrate in biofilters was evaluated in post-larval culture of Nile tilapia the was objective of this work. The experiment was conducted at the Laboratory of Aquaculture, UFVJM University, Brazil, from July 21 to August 3, 2011. Post-larvae of Nile tilapia at density 13.3 post-larvae/L were grown in tanks containing biofilters with 100% calcareous shell; 70% calcareous shell/30% gravel; 50% calcareous shell/50% gravel; 30% calcareous shell/70% gravel; 10% calcareous shell/90% gravel; 100% gravel; tank without biofilters and control, in completely randomized design with seven treatments and three repetitions. Calcareous shell provided better water conditions than tanks without biofilter or containing only gravel, keeping the parameters suitable for Nile tilapia farming. Although ammonia levels were close to the desired upper limit, they had no influence on morphological parameters (total length, standard length, height and weight). The rate 30% shell/70% gravel is recommended as biofilter substrate, as it provided the best nitrification rate during the experiment.
The Landscaping in cities provides, continuosly, people with high visual, emotional and physical performance with access to diferente plant morphological architectures, leaves , trunks, flowers, fruits and seeds colors. The shadows caused by the leaves of the trees allows a comfortable atmosphere with the temperature reduction, air humidity increase and environment aromatization of gardens, parks and streets by the volatile compounds emission by leaves, stems and flowers. The combinations of these environmental factors improve the plant, animal and Homo sapiens great development. The plant architectural distribution in high-slope areas minimizes problems such as floods and landslides in urban centers, being an economically viable and sustainable alternative for heritage preservation, the physical structure soil and optimization of water flow. The landscaping of cities is the perfect setting for meeting people, recording videos and photos for personal archives, social media, developing personal and business marketing projects and network.
In aquaponic systems, the residual water from the cultivation of fish is not enough to meet the nutritional demands of plants. The main objective of this study was to investigate how to adjust a nutritive solution for the cultivation of lettuce (Lactuca sativa L.) in aquaponics, based on hydroponics. The treatments included six separate crops of lettuce in an aquaponic system, while the hydroponic system served as the control. In each treatment, three blocks were used to quantify the parameters of ‘head’ diameter, number and dry weight of leaves, shoot dry weight, root dry weight, total dry weight, and the concentration and accumulation of nutrients in the total dry weight of the lettuce plants. The lower nutrient supply led to the occurrence of the lowest total dry weight in the C2 leaf crops when compared to that of the other crops of aquaponics, which had adequate time for system maturation. The system maturation and the use of a balanced solution in the C5 and C6 crops allowed the head diameter of the aquaponics plants to be equal to those of the hydroponics plants. In the aquaponic system, N and Fe were the most limiting macronutrient and micronutrient, respectively. To produce lettuce in an aquaponic system, it is necessary to ‘ripen’ the crop water for at least 30 days, and supplement micronutrients in the form of mineral fertiliser.
Marketing the inflorescences of Comanthera elegans (Bong.) L.R. Parra & Giul. represents a source of income to many families from extractives communities in the portion of the Espinhaço Range located in the state of Minas Gerais, Brazil. Cultivating this species stands out by allying income generation with conservation since the species is currently endangered. This study aimed to assess aspects of the development of C. elegans in three cultivation systems: beds, rows, and whole area. Sowing took place in January 2009 and the inflorescences were harvested in May 2010, which characterized the experimental period. Emergence; plant density; rates of flowering, mortality, resprouting, and recruiting of new individuals; and production of inflorescences per plant and per area were assessed. Emergence began approximately 50 days after sowing. Plant density ranged from 130 to 350 plants.m -2 among the three cultivation systems. The highest mortality rate (18%) was observed at the peak of the dry season (August) and the overall mortality rate over one reproductive cycle was 49%. Of the plants that lost the aerial part, 36% resprouted. . Keywords: Campos Rupestres, Eriocaulaceae, production, management, dry cut flowers. RESUMO Desenvolvimento da sempre viva (Comanthera elegans (Bong.) L.R. Parra & Giul.) em três sistemas de cultivoA comercialização das inflorescências de Comanthera elegans (Bong.) L.R. Parra & Giul. representa fonte de renda para muitas famílias de comunidades extrativistas da porção mineira da Serra do Espinhaço. O cultivo representa uma importante alternativa de geração de renda aliada à conservação, já que a espécie consta em lista de ameaçadas. Objetivou-se com o presente trabalho avaliar os aspectos do desenvolvimento de C. elegans em três sistemas de cultivo: em canteiro, faixa e área total. O semeio ocorreu em janeiro de 2009 e a colheita das inflorescências em maio de 2010 caracterizou o final do período experimental. Avaliou-se a emergência, a densidade de plantas, as taxas de floração, de mortalidade, de rebrota e de recrutamento de novos indivíduos e a produção de inflorescências por planta e por área. A emergência iniciou aproximadamente 50 dias após o semeio. A densidade de plantas variou entre 130 e 350 plantas.m -2 nos três sistemas de cultivo. A maior taxa de mortalidade (18%) foi observada no pico da estação seca (agosto) e a taxa de mortalidade acumulada durante um ciclo reprodutivo foi de 49%. Das plantas que perderam a parte aérea, 36% rebrotaram. O brotamento e a germinação de sementes contribuíram com 30 e 3% do recrutamento de novos indivíduos. C. elegans apresentou duas florações (abril-maio de 2009 e abril-maio de 2010): 5,4% das plantas floresceram na primeira e 78%, na segunda floração. Cada planta produziu entre 3-178 inflorescências, e a maior produção de inflorescências, em peso (232 g.m -2 ) e número (2910 inflorescências.m -2 ), foi observada no sistema de cultivo em canteiros, o que corresponde a 1624 Kg.ha -1 . Palavras-chave: Campos Rupestres, Eriocaulaceae, prod...
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