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Pelotas, Brazil

Gouvea A.De.F.G.,State University of Mato Grosso do Sul | Trugilho P.F.,Caixa Postal | Colodette J.L.,Federal University of Vicosa | Bianchi M.L.,Cx.P. 3037 | And 2 more authors.
Scientia Forestalis/Forest Sciences | Year: 2011

The evaluation of technological characteristics of wood requires measurements of a great amount of samples to obtain precise results, which has led to the search of new methodologies and equipments that would make this work faster and, at the same time, would reduce the operation costs if possible in field condition. The objective of the present work was to check the relationship among certain chemical and physical characteristics of wood and cellulose pulp, obtained through laboratorial analyses (destructive), with non destructive methods, namely: pilodyn, resistograph, NIRS and extensometer, applied to the living tree. The results showed that the wood basic density presented positive correlation with the longitudinal residual strain (LRS) and width (AMP) and negative correlation with the penetration of the pin of pilodyn (PILO). The values of DRL presented positive correlation with the wood cellulose content and negative correlation with the lignin content. The AMP presented negative correlation with the lignin content. It was observed that the LRS, PILO and AMP presented positive correlation with the syringyl/guaiacyl (S/G) ratio. The LRS and AMP presented negative correlation with the kappa and the viscosity but positive with the pulping yield. In the Near Infra-red Spectroscopy- NIRS, the correlations obtained through the external prediction values and laboratory by using models created from samples from these experiments were better than the values predicted by an existing model constructed by a Brazilian Forest Company. Source

Pinto E.P.,Federal University of Pelotas | Perin E.C.,Federal University of Pelotas | Schott I.B.,Federal University of Pelotas | da Silva Rodrigues R.,Federal University of Pelotas | And 3 more authors.
Postharvest Biology and Technology | Year: 2016

It is known that ultraviolet light has a major role in the ontogeny of the plants, and may also induce the production of secondary metabolites. The aim of this study was to evaluate the cultivar 'Concord', produced in conventional and organic production systems, treated with UV-C radiation after harvest. Grapes were evaluated for chemical composition, the antioxidant activity and the relative accumulation of gene transcripts related to secondary metabolism of the grapevine. UV-C radiation stimulated gene expression of the phenolic compounds biosynthetic and also caused accumulation of these metabolites, and these changes were dependent on the production system. The results showed that the conventional grapes had a higher accumulation of transcripts of the genes PAL, CHS and STS which ANS compared to organically produced grape. After harvest, UV-C stimulates the accumulation of transcripts of these genes. Organic grapes had a higher antioxidant activity. UV-C radiation resulted in an increase of antioxidant activity in grapevines from different production systems. © 2016 Elsevier B.V. Source

Faria R.R.,Programa de Pos graduacao em Ecologia e Conservacao | Araujo A.C.,Caixa Postal
Flora: Morphology, Distribution, Functional Ecology of Plants | Year: 2010

In Brazil, studies focusing on reproductive biology and aspects of pollination in the genus Ruellia have demonstrated common characteristics such as pollination by hummingbird, the predominance of self-fertility and spontaneous self-pollination. The objectives of this study were to describe the floral biology, nectar production, the reproductive system, the effect of pollination intensity and flowering phenology of Ruellia angustiflora, as well as keeping a record of the hummingbirds that visit the flowers of this species. Data collection was performed in a stretch of the Salobrinha stream in the Serra da Bodoquena, Mato Grosso do Sul, from August 2005 to July 2006. R. angustiflora flowered throughout most of the study period; it has diurnal anthesis and has increased nectar production in the morning hours with decreasing production rates during the day. The results of the reproduction experiments indicate self-fertility and pollen limitation in R. angustiflora. Among experiments with different pollination intensity there was no significant difference in fruit formation. Four hummingbird species were observed visiting the flowers of R. angustiflora, and Phaethornis pretrei was the most frequent followed by females of Thalurania furcata. According to its behavior and frequency of visits, P. pretrei can be considered the main pollinator of R. angustiflora in the study area. The experiments on flowers treated with different pollen loads indicate that most successful fruit formation in this species is obtained in flowers that received greater pollen loads on their stigmas. Besides, data suggest that major success in fruit set could be reached with more than three visits of P. pretrei. © 2009 Elsevier GmbH. All rights reserved. Source

Machado K.K.G.,CCA UEMA | De Lemos R.N.S.,Caixa Postal | Medeiros F.R.,Sao Paulo State University
Revista Caatinga | Year: 2014

The fall armyworm is a pest that feeds on various botanies species. The objective of this experi-ment was to study the biology of this pest in corn and cassava leaves. Caterpillars were collected in area under cultivation with cassava and maintained on artificial diet for two generations. Under controlled conditions in a climatic chamber (B.O.D) in the laboratory (25 ºC, 60 ± 10% RH and photophase 14 hours) were evaluated daily 50 caterpillars in corn treatments and 50 in cassava, where duration and viability of the larval phase and pupal, weight of pupas were observed after 24 hours, deformation percentage of pupas and adults, longevity, fecundity and total life cycle. The viability of larvae fed on leaves of maize and cassava was 74% and 60%, respectively. The larval period of the insects was shorter in maize 16.89 days (seven instars) and cassava 20.08 days (six instars). The pupal phase lasted 11.42 days in cassava treatment and 10.87 in the maize. The pupal weight of females and males was higher in corn 204.91 mg and 198.97 mg, respectively. The biological cycle varied depending on the ingested food. Adult longevity lasted 9.88 days for insects fed on cassava leaves. Therefore, cassava affected the development of S. frugiperda. © 2014, Universidade Federal Rural do Semi-Arid. All rights reserved. Source

de Padua G.P.,Caixa Postal 311 | Zito R.K.,Caixa Postal 311 | Arantes N.E.,Caixa Postal 110 | Neto J.B.F.,Caixa Postal
Revista Brasileira de Sementes | Year: 2010

Seed size has received special attention by researchers, who have studied aspects related to seed performance and the resulting plant. The objectives of this study were to evaluate the effects of seed size on initial plant growth, grain yield and the physiological seed quality of soybeans by testing seeds of three cultivars (BRSMG 752S, BRSMG 790A and BRSMG 750SRR), graded into three sizes (4.0 mm, 5.0 mm and 6.0 mm). No-till planting was done on December 6th, 2007 and the plants thinned 21 days after emergence to 13 plants per meter. Harvesting and seed threshing were done manually on April 11th, 2008. After harvesting, seeds were manually graded into three sizes by using round perforation screens of 6.0 mm, 6.5 mm and 7.0 mm. The field trials were set up in a completely randomized block design and the laboratory analyses followed a completely randomized design, both having a factorial of 3 cultivars × 3 seed sizes and four replicates. Data were submitted to analysis of variance by the F test and means were compared by the Tukey test at the 5% probability level. The analyzed field parameters were plant height and grain yield (kg.ha-1 at 13% moisture) and the laboratory parameters measured were seed germination and vigor, measured by accelerated ageing, classification of seed vigor, seedling length and tests for seedling dry mass. Small seeds (4.0 mm) resulted in shorter plants at harvest with a lower grain yield potential when compared to large seeds (6.0 mm). Physiological seed quality varied among the different sizes of the harvested seeds: best performance was observed with large seeds (7.0 mm) for the three cultivars. The effect of seed size on vigor was significant since large seeds (7.0 mm) had the highest vigor. Source

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