João Avelar Magalhães

Avaliação Agronômica de Variedades de Cana-de-Açúcar para Fins Forrageiros em Rondônia

The agronomic performance of sugarcane varieties (RB 72-454, RB 78- 5148, RB 73-9735, RB 73-9359, RB 83-5486, SP 71-1406, SP 79-1011, CB 45-3, CB 47-355, NA 56-79 and test) introduced in Rondonia - Brazil was evaluated. It was used a randomized blocks design, with three replications. The plantation was carried out in November of 1999 and the harvesting occurred in June of 2001. The plants presented average height of 3,69 m. The RB 83- 5486 presented smaller height and RB 73-9359 was higher than another varieties. RB 78-5148 presented the largest DM content and RB 72-454 the smallest (P 0.01). The average yield of GM and DM were of 208 and 55 t/ ha, respectively, with RB 73-9735 reaching the largest ones, not being different of RB 72-454, RB 78-5148, RB 71-1406, SP 79-1011, CB45-3, CB 47-355 and NA 56-79 (P>0.01). The plants showed average values of 88.0, 7.0, 4.0 and 1.0% of stems, tip, green and dry leaves, respectively. The varieties RB 73-9735, RB 78-5148, RB 73-9359 and CB 47-355 where presented the best general performance, with regard to forage production, sugar content and steam participation.

Polycyclic aromatic hydrocarbons bioaccessibility in seafood: Culinary practices effects on dietary exposure

&NA; This work aimed to determine the effect of culinary practices on the contamination level and bioaccessibility of polycyclic aromatic hydrocarbons (PAHs) in seafood. The selected farmed seafood species (marine shrimp, clams and seaweed) were commercially available in Portugal. The mean concentrations of PAHs varied between 0.23 and 51.8 &mgr;g kg−1, with the lowest value being observed in raw shrimp and the highest in dried seaweed. The number of compounds detected in seaweed and clams (naphthalene, acenaphthene, fluorene, phenanthrene, benzo(b)fluoranthene and benzo(j)fluoranthene) were higher than in shrimp (fluorene and pyrene). Among the PAHs measured, fluorene was the predominant one. There was a significant interaction effect between species and culinary treatment (p < 0.05), thus boiled and dried seaweed samples presented the lowest and the highest levels of fluorene (0.13 and 1.8 &mgr;g kg−1), respectively. The daily intake of PAHs decreased with bioaccessibility, varying from 22% for benzo(k)fluoranthene (in raw clam) to 84% for phenanthrene (in steamed clam). According to the potency equivalent concentrations, screening values and bioaccessibility of PAHs, the consumption of marine shrimp, clam and seaweed is considered as safe for consumers. HighlightsPAHs bioaccessibility in seafood was assessed.Raw shrimp present the lowest and dried seaweed the highest content of PAH.There was a significant interaction effect between species and culinary treatment.

Produção de Forragem, Composição Química e Morfogênese de Panicum maximum cv. Vencedor sob Diferentes Níveis de Adubação Nitrogenada

O efe i to da adubacao nitro ge nad a (O , 4 0 , 80 , 12 0 e 160 mg N / k g so l o ) so br e a producao e composicao quimica da forragem e car a ct er i s ti cas morfo ge n i c as e e st ru tu r ais d e Pa n i c um maximum cv. Vencedor foi avali a do em c ond icoes d e c as a -d e - vege t aca o . O d el in ea mento experimental fo i em blocos casualizados co m t r es r e p eti c oe s . A adub acao nitr oge nada afetou positi v a e linearmente a producao de ma te r i a s eca e o tamanho m e dio d e f olha s, co ntudo implicou em decrescimo s s i gnific a ti v os dos teor e s de fosfo r o . A s maiores t a x as d e ap a r e c i m e nto e de expansao foliar , o maior numero de folhas / perfilho e o t a manho maximo d e fo l has fo r am obtidos , respectivamente , com a aplicacao de 139 , 5 ; 115 , 4 ; 125 , 7 e 105 , 1 m g/N/kg so lo . A efici e ncia de utilizacao e a recupera c ao aparente de N f o ram in ve r sa m e nte pr o p orc i o n ais as do s es d e N aplicadas . A q ualidad e da forragem produzida foi m el hora da p e la a d u b ac a o n itro ge n a d a, a pr es entando maiores teores de N.

Casca de Café na Alimentação de Ovinos Deslanados

Para avaliar o desempenho de ovinos deslanados em crescimento, alimentados com niveis crescentes de casca de cafe, conduziu-se um experimento em Rondonia-RO; em delineamento inteiramente casualizado com quatro tratamentos, representados pelos niveis de inclusao da casca de cafe de 0, 10, 20 e 30% em substituicao ao capim-elefante ( Pennisetum purpureum Schum.) cv. Cameroon e cinco repeticoes, representados pelos animais. A casca de cafe continha 85,2; 11,3; 0,50 e 0,16 % de MS, PB, Ca e P, respectivamente. A sua inclusao na dieta dos ovinos resultou em maiores ganhos de peso (P?0,01), 9,1; 18,8; 14,5 e 49,1 g/dia/animal, respectivamente, para os niveis de inclusao de 0, 10, 20 e 30%; o consumo medio dos animais alimentados com as racoes contendo a casca foi 14,6% inferior ao dos alimentados exclusivamente com capim-elefante (53,7 x 62,9 g de MS/kg de PV 0,75 ).

ASSESSMENT OF LEGUMES WITH POTENTIAL USE AS GREEN MANURE IN THE COASTAL TABLELANDS OF PIAUÍ STATE, BRAZIL

Green manure may lead to physical, chemical, and biological improvements to the soil. However, the information on its use in the Brazilian Northeast is scarce. The aim of this study was to assess the phenological cycle and phytomass productivity of seven legume species. This study was conducted in the second semester of 2015 in a completely randomized design with seven treatments and four replications. Plant height, fresh mass of shoot (FMS), dry mass of shoot (DMS), fresh mass of root (FMR), and dry mass of root (DMR) were determined at 100 days after sowing. Germination, flowering, and pod maturation were also assessed. The highest averages of FMS were observed in Crotalaria breviflora and Crotalaria mucronata, followed by Canavalia ensiformis, whereas the highest averages of DMS were observed in C. breviflora, C. ensiformis, C. mucronata, and Cajanus cajan cv. IAPAR 43. The highest averages of FMR were obtained by C. breviflora and C. mucronata, followed by C. cajan cv. Fava Larga. The species C. mucronata, C. cajan cv. IAPAR 43, and C. breviflora presented the highest averages of DMR. In addition, C. juncea, C. ensiformis, and C. cajan cv. IAPAR 43 were the earlier species regarding flowering, while C. cajan cv. Fava Larga was the later species. C. juncea was the earliest among all studied species regarding pod maturation. The tested legume species obtained promising initial results during the assessment period, being able to meet the expectations of biomass production and contributing to soil sustainability in this region.

Produtividade de forragem e composição química de Stylosanthes capitata cv. Lavradeiro sob níveis de fósforo

The effects of phosphorus levels (0, 40, 80 and 120 kg of P2O5 ha) on green dry matter (GDM), chemical composition and nodulation of Stylosanthes capitata cv. Lavradeiro were evaluated under field conditions in Roraima ́s savannas. Phosphorus fertilization increased significantly (P<.05) GDM yields, nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg) and potassium (K) concentrations and number and dry weight of nodules. Maximum GDM yields and Ca, Mg and K contents were obtained with the application of 89.4; 56.2; 113.1 and 75.6 kg of P2O5 ha, respectively, while the N and P contents and number of nodules were directly proportional to P levels. The P critic level, related to 90% of GDM maximum production, was estimated at 2.43 g kg. The P efficiency utilization was inversely proportional to the P rates applied.

Produtividade de forragem e micorrrização de pastagens de Trachypogon plumosus sob adubação fosfatada

The effect of phosphate fertilization (0, 30, 60, 90 and 120 kg of P2O5 ha) on green dry matter (GDM) yield and the occurrence of arbuscular mycorrhiza fungi (AMF) of Trachypogon plumosus pastures was evaluated under field conditions of Roraima’s savannas. Phosphate fertilization positively and significantly (P<0.05) affected GDM, phosphorus concentrations and extraction, but linearly reduced spore numbers and root colonization rates by AMF. Maximum GDM yields, phosphorus concentrations and uptake were obtained with the application of 91.8; 76.7 and 82.6 kg of P2O5 ha, respectively. The phosphorus efficiency utilization was inversely proportional to the phosphorus rates applied.

Características morfogênicas e estruturais de Megathyrsus maximus cv. Tanzânia-1 sob intensidades de desfolhação.

O efeito de intensidades de desfolhacao (20, 30, 40 e 50 cm acima do solo) sobre a producao de forragem e caracteristicas morfogenicas e estruturais de Megathyrsus maximus cv. Tanzânia-1 foi avaliado nos cerrados de Roraima.

Caracterização do processamento artesanal da carne de caranguejo-uçá Ucides cordatus e perfil socioeconômico dos quebradores

The Ucides cordatus mangrove crab is one of the most economically important crustaceans in Brazil, being a source of income and work for the fishing communities. Its consumption is one of the Northeastern cuisine attractions, supporting the thematic restaurants greatly appreciated by tourists. Crabs not sold by fishermen or traders are processed locally for meat or pasta crab extraction. This work aimed to diagnose the socioeconomic situation of the workers involved in this activity, as well as the hygienicsanitary conditions of processing, handling and packaging of crabmeat in places called

Produtividade de forragem, composição química e morfogênese de Megathyrsus maximus cv. Mombaça sob períodos de descanso

The effects of rest periods (14, 21, 28, 35, 42 and 49 days) on green dry matter (GDM) yield, chemical composition and morphogenetic and structural characteristics of Megathyrsus maximus cv. Mombaça were evaluated under natural field conditions. GDM yields and regrowth increased consistently with highest rest periods. The leaf appearance and leaf expansion rates are inversely proportional to the rest periods, occurring the inverse for average leaf length, leaf area index and foliar senescence rate. Maximum GDM yields, regrowth yields, number of leaves tiller, average leaf length and leaf area index were obtained with rest periods at 36.4; 39.2; 40.8; 39.6 and 41.3 days. These data suggest that grass grazing at 35 to 42 days of rest period were optimal for obtain maximum yields and regrowth of rich forage.