Objectives. To investigate the effects of dietary guidelines on sugar and sugar intake at day nurseries, and other potential risk factors on dental caries in two groups of low socio-economic nursery schoolchildren. Design. Nursery based, longitudinal study. Setting. Metropolitan area of Recife, north-eastern Brazil. Sample and methods. The study population comprised 510, 3-year-old low socioeconomic nursery schoolchildren. Sugar intake at the nursery was based upon a weighed inventory method during 2 non-consecutive days. Parents answered a questionnaire. Results. Children attending nurseries not adopting guidelines on reduction of sugar intake had a higher caries risk, with an odds ratio of 3 . 6 compared to those attending nurseries with guidelines. A higher caries increment was related to higher daily frequency and weight of sugar intake at nursery, overall daily frequency of sugar intake (sugar intake at home plus nursery), past caries experience, use of fluoride, and habits related to toothbrushing. Children having more than 32 . 6 g of sugar daily at nursery were 2 . 99 times more likely to have high caries increment than those having less than that amount. Conclusions. Sugar intake at nursery and the adoption of guidelines on sugar were associated with lower caries increment in low income nursery schoolchildren. A number of modifiable factors such as a higher daily frequency and weight of sugar intake at nursery, use of fluoride and habits related to toothbrushing were strongly related to caries increment.

No abstract

The objective of this work was to evaluate the morphogenetic and structural characteristics of xaraes palisadegrass submitted to three cutting heights (15, 20 and 25 cm) when the sward reached 95% of light interception during regrowth. The experiment was carried out according to a complete randomized block design with three replications. The sward surface height under the cutting condition of 95% of light interception was very homogeneous with values around 30 cm. The increase in cutting height reduced the leaf elongation rate and the number of live leaves but increased stem elongation rate. As the cutting criterion was the same, before the intense competition for light, the variation in the cutting severity had a small influence on the morphogenetic and structural characteristics of this grass. In the summer, due to the better growth conditions, the plants presented a higher tissue renewal, which was characterized by a higher leaf elongation rate, reduced leaf lifespan and leaf senescence rate when compared to the other season of the year. Under intermittent defoliation conditions, the regrowth of xaraes palisadegrass can be interrupted at a sward height of 30 cm (frequency) keeping a residual height of 15 cm.

Understanding of the morphogenetic characteristics allows comprehension of aspects related to the form and function of forage plants, providing opportunities to identify potentially high productive plants and distinct defoliation management requirements. The objective of this experiment was to carry out a comparative study of ten tropical forage grasses using morphogenetic and structural variables. Treatments corresponded to grasses of the Panicum genus (P. maximum cultivars Tanzânia and Mombaça) and the Brachiaria genus (B. brizantha cultivars Piatã, Marandu, Xaraés, Capiporã and Arapoty; B. decumbens cultivar Basilisk; B. humidicola cultivars Comum and Tupi), evaluated under free growth conditions.. Response variables were leaf appearance and elongation rates, phyllochron, stem elongation rate, final leaf length, number of live leaves per tiller, leaf life span and tiller appearance, death and survival rates. There was difference between cultivars for these variables, indicating a large variability within plants. Considering the morphogenetic and structural variables of leaves and tillers, B. brizantha had a similar pattern of variation to those of P. maximum, and B. Decumbens, similar to those of B. humidicola. Tiller appearance was large at the onset of the experiment and second and third generations comprised the large majority of tiller population for the cultivars Mombaça, Tanzânia, Xaraés and Capiporã. Group analysis based on plant morphogenetic and structural characteristics of leaves and tillers was an interesting way of grouping cultivars, indicating the importance and the potential of using morphogenesis in plant selection and evaluation programmes.

-This work was performed aiming to evaluate the morphogenetic and structural characteristics of Andropogon gayanus cv. Planaltina species submitted to three cutting heights (20, 27 and 34 cm). The three cutting heights were allocated in experimental units (12 m 2 ) in a complete randomized block design with three replications. The cuts were done when the light interception by the sward reached 95%. At this moment, the sward height revealed itself constant with values close to 50 cm. The lowest cutting height (20 cm) influenced negatively the final leaf blade length, the number of live leaves, the leaf lifespan, the stem elongation rate and the tiller population density, and it influenced positively the phyllochron and the leaf senescence rate. Probably, cuts at 20 cm height caused a high decapitation and death of the tillers. The worst growth conditions in addition to the blossom of this specie occurred during fall resulted in higher stem elongation rates and number of live leaves, and lower phyllochron, final leaf blade length, and leaf lifespan. The sward height can be used as a practical and efficient criterion in the management of andropogon grass. Under intermittent management conditions, the regrowth of andropogon grass must be interrupted when the sward reaches 50 cm height, and the defoliation must be interrupted when the stubble height is close to 27 cm.Key Words: Andropogon gayanus, ecophysiology, light interception, morphogenesis, sward height Características morfogênicas e estruturais do capim-andropógon submetido a diferentes alturas de corte RESUMO -Este trabalho foi realizado com o objetivo de avaliar as características morfogênicas e estruturais da espécieAndropogon gayanus cv. Planaltina, submetida a três alturas de corte (20, 27 e 34 cm). As três alturas de corte foram alocadas às unidades experimentais (12 m 2 ) em delineamento de blocos completos casualizados com três repetições. Os cortes foram realizados quando a interceptação luminosa pelo dossel atingiu 95%. A altura do dossel nesse momento mostrou-se constante, com valores próximos a 50 cm. A menor altura de corte (20 cm) influenciou negativamente o comprimento final da lâmina foliar, o número de folhas vivas, a duração de vida da folha, a taxa de alongamento de colmo e a densidade populacional de perfilhos, e positivamente o filocrono e a taxa de senescência de folhas. Provavelmente, cortes a 20 cm de altura causaram elevada decapitação e morte de perfilhos. As piores condições de crescimento junto do florescimento ocorrido durante o outono resultaram em maiores taxas de alongamento de colmos e número de folhas vivas e em menor filocrono, comprimento final da lâmina foliar e duração de vida da folha. A altura do dossel pode ser utilizada como critério prático e eficiente de manejo do capim-andropógon. Em condições de manejo intermitente, a rebrotação deve ser interrompida quando o dossel atingir 50 cm de altura, e a desfolhação, quando a altura de resíduo ficar próxima de 27 cm.