Vegetative Propagation of \u3cem\u3eStylosanthes scabra\u3c/em\u3e

One way to multiply genetically desirable plants in a more uniform manner is to use vegetative propagation, such as using plant cuttings. This technique multiplies a single plant into several, in an easy low-cost system (Fachinello et al. 2005), so it is useful in plant breeding. This technique may be enhanced through the use of hormonal regulators, with indolebutyric acid (IBA) being most frequently used, because of its stability in hydroalcoholic solution, low sensitivity to biological degradation and good establishment of adventitious roots (Fachinello et al. 1995). In spite of its large-scale use for fruit production, the technique is not commonly used for forage species, such as Stylosanthes. We evaluated different concentrations of IBA for root establishment and initial development of Stylosanthes scabra cuttings

Morphological Divergence among Progeny of Macroptilium lathyroides Accessions from the Semi-Arid Region of Pernambuco, Brazil

Macroptilium is a legume genus with approximately 20 species, usually annual or biennial, herbaceous and distributed mainly in the Americas. It is widely used as a forage resource in grasslands and usually fixes atmospheric N. Martins et al. (2001) indicated that half-sib family selection with progeny testing is the most common plant breeding method used in Brazil. In the scientific literature, however, there are few studies dedicated to Macroptilium spp. This study evaluated morphological divergence among Macroptilium spp. progeny from accessions collected in 4 counties located in the semi-arid region of Pernambuco State, NE Brazil

Leaf Epidermal Descriptors of Forage from Caatinga, NE Brazil

In the Brazilian semi-arid region, the predominant vegetation is the Caatinga, which has a diversity of plant species, some endemic and presenting forage potential. The characterization of the plant anatomy is important for animal diet studies, using a microhistological technique (Scott and Dahl 1980) for estimating the diet botanical composition from ruminant faeces. This paper determined leaf epidermal descriptors for Caatinga species using microscopic slides

Contribution from Tree Legumes to Mixed Grass-Legume Pastures

Legumes and associated microorganisms may fix N from atmosphere and benefit grass on mixed grass-legume pastures. Nitrogen may be transferred by different mechanisms, including direct transfer of N compounds by roots, decomposition of nodules, roots, litter from legume (Nair 1993), and through animal excreta after legume intake by cattle. Silvopastoral systems including tree legumes may become a viable option in tropical regions, considering the increasing prices of N fertilizers compared to farm products such as beef and milk. This experiment evaluated legume contribution on mixed grass-legume pastures in the coastal region of Pernambuco State, Brazil

Comportamento de novas progênies de sorgo forrageiro para o Semi-Árido Pernambucano

This work is related to 45 recently developed forage sorghum varieties. It aims to offer to Pernambuco Semi-Arid region farmers forage sorghum (Sorghum bicolor L.) varieties with higher yield capacity. The trials were carried out in Caruaru, São Bento do Una, Arcoverde and Serra Talhada involving nine different environments made up with combinations of years and localities. The experimental design was in randomized blocks with three replications in 1982, and without replications in 1983 and 1984. Analysis of dry matter (DM) productivity stability was also realized using the linear regression coefficient following the Eberhart & Russel Model. Progenies 467-4-2, 380-5-1, 322-1-3 and 484-1-1 showed outstandig behavior across the environments. The two first ones yielded 12.47 and 11.45 t/ha of DM and had a linear regression b = 1.03. The last two ones yielded 10.67 and 10.49 t/ha of DM and had a linear regression b = 0.90, which characterizes them as adapted to a less favorable environment. The sorghum variety IPA 7301218, previously recommended for planting in Pernambuco, had inferior performance among all other treatments. Este trabalho relata o desempenho de 45 novas progênies de sorgo forrageiro (Sorghum bicolor L.) objetivando propiciar aos produtores do Semi-Árido de Pernambuco cultivares de sorgo mais produtivas. Os testes foram conduzidos em Caruaru, São Bento do Una, Arcoverde e Serra Talhada, totalizando nove ambientes distintos, formados pelas combinações de anos e locais. O delineamento experimental foi o de blocos ao acaso, com três repetições, em 1982, e sem repetição, em 1983 e 1984. Efetuou-se, também, a análise de estabilidade da produtividade de matéria seca, pela estimativa do coeficiente de regressão linear, de acordo com o modelo proposto por Eberhart & Russel. As progênies 467-4-2, 389-5-1, 322-1-3 e 484-1-1 destacaram-se favoravelmente nas avaliações. As duas primeiras apresentaram uma produtividade média de 12,47 e 11,45 t/ha, respectivamente, de MS, e um coeficiente de regressão linear b = 1,03 que as caracterizam como estáveis. As duas últimas apresentaram uma produtividade média de 10,67 e 10,49 t/ha de MS, respectivamente, e um coeficiente de regressão linear b = 0.90, que as caracterizam como adaptadas a ambiente menos favorável. A cultivar de sorgo forrageiro IPA 7301218, previamente recomendada para plantio em Pernambuco, teve um desempenho inferior a todos os demais tratamentos.

Adaptability and Stability of Productive Characteristics on the Selection of Pennisetum purpureum Schum. Clones Grazed by Sheep

Elephant grass (Pennisetum purpureum Schum.) is one of the most widely used forages in Brazil, due to its high potential productivity, forage quality, palatability, vigour and persistence. Dwarf types of elephant grass are the object of selection programs for their higher leaf/stem ratio and lower grazing height, resulting in more efficient pasture management. They have high potential for ruminant production (Almeida et al. 2000), but have markedly different morphological and productive characteristics (Cunha et al. 2011) to tall varieties of the same species. Adaptability and stability analyses are selection tools which allow identification of plant responses to different environments (Cruz and Regazzi 2001) and can identify stable productive clones across a range of environments. This study evaluated the genotype x environment interaction for productive characteristics of P. purpureum clones grazed by sheep

Canopy Height and Its Relationship with Leaf Area Index and Light Interception of Tropical Grasses

Photosynthetic tissues, mainly green leaves, are the major component of forage growth and development. The amount of these tissues in a forage plant is influenced directly by the cutting management, which is based on cutting frequency and stubble height. It is usual to recommend as a management practice to cut (or graze) the forage whenever it reaches a given stubble height. Brougham (1956) stated that, when the forage canopy is intercepting 95% of the photosynthetic active radiation, this is the critical leaf area index (LAI), which means the forage is near its maximum growth rate without shading itself. There is also the optimum LAI, where the forage reaches the maximum point of mass accumulation, indicating time to start grazing or cut. Generally the critical and optimum LAI have close values, but they are not necessarily the same (Brown and Blaser, 1968). This trial evaluated the relationship among canopy height, leaf area index, and light interception in ten different tropical grasses

Profiling exercise intensity during the exergame Hollywood Workout on XBOX 360 Kinect®

Background Despite the increasing popularity of exergame practice and its promising benefits in counteracting physical inactivity, limited research has been performed to document the physiological responses during an exergame session. This study aims (i) to investigate the responses of heart rate (HR) and oxygen uptake (${\dot{\rm V}}{{\rm{O}}_{\rm{2}}}$V˙O2) during an exergame session and to compare with HR and ${\dot{\rm V}}{{\rm{O}}_{\rm{2}}}$V˙O2 measured during joystick session and (ii) to compare HR and ${\dot{\rm V}}{{\rm{O}}_{\rm{2}}}$V˙O2 obtained during exergame and joystick session with those HR and ${\dot{\rm V}}{{\rm{O}}_{\rm{2}}}$V˙O2 associated with first and second ventilatory thresholds (VT1 and VT2, respectively) obtained during a maximal graded exercise test. Methods A total of 39 participants performed a maximal graded exercise test to determine maximal oxygen uptake (${\dot{\rm V}}{{\rm{O}}_{\rm{2}}}\max$V˙O2max), VT1, and VT2. On separate days, participants performed an exergame and traditional sedentary game (with a joystick) sessions. The time that participants remained with HR and ${\dot{\rm V}}{{\rm{O}}_{\rm{2}}}$V˙O2 below the VT1, between the VT1 and VT2 and above the VT2 were calculated to determine exercise intensity. Results Heart rate and ${\dot{\rm V}}{{\rm{O}}_{\rm{2}}}$V˙O2 were below VT1 during 1,503 ± 292 s (86.1 ± 16.7%) and 1,610 ± 215 s (92.2 ± 12.3%), respectively. There was an increase in HR and ${{\dot {\rm V}}}{{\rm{O}}_{\rm{2}}}$V˙O2 as a function of exergame phases, since HR mean values in the ‘warm-up’ period (119 ± 13 bpm) were lower than the ‘main phase’ (136 ± 15 bpm) and ‘cool-down’ periods (143 ± 15 bpm) (p 0.05) and lower than the ‘cool-down’ (28.0 ± 4.8 mL.kg−1.min−1) (p < 0.001). For all times of the joystick session, average HR and ${\dot {\rm V}}{{\rm{O}}_{\rm{2}}}$V˙O2 were below the VT1 levels. Conclusion Exergames can be classified as light to moderate exercise. Thus, exergames could be an interesting alternative to traditional forms of exercise