997 resultados para 110-674A
Resumo:
O trabalho foi realizado com o objetivo de determinar a produção de matéria seca na planta pelos cultivares de trigo BH 1146, de porte alto e com tolerância a deficiência hídrica e IAC 24 - Tucuruí, de porte baixo e com média tolerância e deficiência hídrica, sendo ambas de ciclo médio, em duas disponibilidades de água, sequeiro e irrigado. 0 experimento foi conduzido em Latossolo Roxo, distrófico-argiloso, adubado com 20 kg de N e 90 kg de P2O5 por hectare. Para determinação do peso da matéria seca produzida das plantas, foram coletados ao 10 dias de idade, início de perfilhamento; aos 30 dias, elongamento do colmo; aos 50 dias, emborrachamento; aos 70 dias floração, aos 90 dias, grão leitoso; e aos 110 dias, maturação. Os resultados mostram que a irrigação determina mais acúmulo de matéria seca por planta e matéria Seca por área, nas duas cultivares e em todas as idades.
Resumo:
The relationship between female body size and egg number was examined in the snake Bothrops jararaca (Wied, 1924). Some authors have demonstrated that the estimated clutch size may be affected by the inclusion or exclusion of dead neonates or non-developed eggs. The reproductive system of 254 mature females newly arrived from nature was examined and 29.55% (n=75) had eggs in the oviducts in different stages of embryonic development. The presence of atresic eggs was observed in 34.5% of those females. A significant difference was observed in the number of eggs in the right and left oviducts (t=9.48, P<0.001), but not in the number of atresic eggs (t=1.110, P=0.278). The correlation of female body size and egg number was greater when all, the normal and atresic eggs were considered (r=0.63, P<0.001). The exclusion of atresic eggs from the clutch size decreased slightly this correlation (r=0.54, P<0.001).
Resumo:
v.110 (1953)
Resumo:
Callinectes danae Smith, 1869 e C. ornatus Ordway, 1863 constituem uma parcela importante da produção pesqueira na Baía de Guanabara. Ambas espécies compõem uma fração significativa da fauna-acompanhante sendo exaustivamente descartadas pelas pescarias de arrasto de camarões na costa brasileira. As curvas de crescimento de C. danae e C. ornatus foram calculadas por meio da análise de progressão modal. Para estimar os parâmetros biológicos, foi aplicado o modelo de crescimento de Bertalanffy e para estimar a longevidade foi usada a sua fórmula inversa. As curvas de crescimento foram: ♂ LC = 120 (1 - e -0,005t ), ♀ LC = 113 (1 - e -0,005t); ♂ LC = 94 (1 - e -0,005t ) e ♀ LC = 110 (1 - e -0,005t ), respectivamente para C. danae e C. ornatus. A longevidade alcançada para as duas espécies foi em torno de 2,5 anos, além de validar as curvas de crescimento. O estudo do crescimento em crustáceos é de extrema importância, pois além de fornecer a informação biológica básica para o grupo, os parâmetros estimados subsidiam o ordenamento e manejo pesqueiro das espécies exploradas.
Resumo:
Leptodactylus(Lithodytes) lineatus (Schneider, 1799) is an Amazonian leaf litter frog considered rare or uncommon in several studies on anuran communities. Despite being a widely distributed frog in Amazonian forests, knowledge of the biology and ecology of this species is relatively scarce. This species has been reported to live in association with leaf-cutter ant nests (Atta spp.) during the breeding period. In this paper we present data on the seasonality of this species and some reproductive information gathered at a locality of Rondônia state, northwestern Brazil. Field work was carried out between April 2001 and March 2002, with the use of pitfall traps with drift fences as a survey method. Leptodactylus (L.) lineatus had a higher capture frequency in this locality compared to that of other studies carried out in other Amazonian localities, possibly because this species has secretive habits, such as calling and breeding from nests of leaf-cutting ants, and are difficult to find during visual encounter surveys. The breeding period occurs between October and March. Calling males and egg-bearing females were found between September and February and juvenile recruitment occurred mainly from the end of the rainy season to the beginning of the dry season (February to June). Males and females show sexual dimorphism in SVL, females being significantly larger than males. The number of ovarian eggs per female varies from 110 to 328 and analyses indicate that there is a significant correlation with SVL.
Resumo:
v. 110 1999
Resumo:
The dynamics of the bird community in a small forest fragment was evaluated along seven years in relation to changes in the surrounding landscape. The study area is an Araucaria forest fragment in Southern Brazil (state of Paraná). The sampling period covered the years 1988 through 1994 and the mark-release-recapture method was utilized. The landscape analysis was based on Landsat TM images, and changes in exotic tree plantations, native forest, open areas (agriculture, pasture, bare soil, and abandoned field), and "capoeira"(native vegetation < 2 m) were quantified. The relationship between landscape changes and changes in abundance diversity of forest birds, open-area birds, forest-edge birds, and bamboo specialists was evaluated. Richness estimates were run for each year studied. The richness recorded in the study area comprised 96 species. The richness estimates were 114, 118 and 110 species for Chao 1, Jackknife 1 and Bootstrap, respectively. The bird community varied in species richness, abundance and diversity from year to year. As for species diversity, 1991, 1993 and 1994 were significantly different from the other years. Changes in the landscape contributed to the increase in abundance and richness for the groups of forest, open-area and bamboo-specialist species. An important factor discussed was the effect of the flowering of "taquara" (Poaceae), which contributed significantly to increasing richness of bamboo seed eaters, mainly in 1992 and 1993. In general, the results showed that landscape changes affected the dynamics and structure of the bird community of this forest fragment over time, and proved to have an important role in conservation of the avian community in areas of intensive forestry and agricultural activities.