Basic density and pulp yield relationship with some chemical parameters in eucalyptus trees

The objective of this work was to evaluate the use of basic density and pulp yield correlations with some chemical parameters, in order to differentiate an homogeneous eucalyptus tree population, in terms of its potential for pulp production or some other technological applications. Basic density and kraft pulp yield were determined for 120 Eucalyptus globulus trees, and the values were plotted as frequency distributions. Homogenized samples from the first and fourth density quartiles and first and fourth yield quartiles were submitted to total phenols, total sugars and methoxyl group analysis. Syringyl/guaiacyl (S/G) and syringaldehyde/vanillin (S/V) ratios were determined on the kraft lignins from wood of the same quartiles. The results show the similarity between samples from high density and low yield quartiles, both with lower S/G (3.88-4.12) and S/V (3.99-4.09) ratios and higher total phenols (13.3-14.3 g gallic acid kg-1 ). Woods from the high yield quartile are statistically distinguished from all the others because of their higher S/G (5.15) and S/V (4.98) ratios and lower total phenols (8.7 g gallic acid kg-1 ). Methoxyl group and total sugars parameters are more adequate to distinguish wood samples with lower density.

Forage yield and quality of a dense thorny and thornless "jurema-preta" stand

The objective of this work was to compare forage production and quality of thorny and thornless "jurema-preta" (Mimosa tenuiflora (Willd.) Poiret) in a dense planted stand, subjected to annual pruning of fine branches, in Patos, PB, Brazil. The experiment consisted of two treatments (thornless and thorny "jurema-preta") in a complete randomized block design, with ten replicates of two linear plots subdivided in time. Forage mass and chemical composition of fine branches and the basal diameter of plants were measured during five years. Pruning decreased (p<0.05) increments in basal diameter and forage production. Annual dry matter yields reached 4,108 and 5,833 kg ha-1, respectively, for thornless and thorny plants, and forage quality was similar (p>0.05) for both genotypes. This roughage fodder (minimum NDF and ADF averages were 56±1.1% and 43±1.0%, respectively) had low P and K concentrations. Its average crude protein content was greater than 9.9±0.5%, which exceeds the minimum necessary for animal maintenance. Both "jurema-preta" genotypes tolerated pruning of fine branches and contributed with a significant amount of roughage fodder for animal maintenance in the dry season.

Maize yield and rainfall on different spatial and temporal scales in Southern Brazil

This study aimed to establish relationships between maize yield and rainfall on different temporal and spatial scales, in order to provide a basis for crop monitoring and modelling. A 16-year series of maize yield and daily rainfall from 11 municipalities and micro-regions of Rio Grande do Sul State was used. Correlation and regression analyses were used to determine associations between crop yield and rainfall for the entire crop cycle, from tasseling to 30 days after, and from 5 days before tasseling to 40 days after. Close relationships between maize yield and rainfall were found, particularly during the reproductive period (45-day period comprising the flowering and grain filling). Relationships were closer on a regional scale than at smaller scales. Implications of the crop-rainfall relationships for crop modelling are discussed.

Growth, yield, water and effluent quality in ponds with different management during tambaqui juvenile production

The objective of this work was to evaluate the effect of pond management on fish feed, growth, yield, survival, and water and effluent quality, during tambaqui (Colossoma macropomum) juvenile production. Fish were distributed in nine 600 m² earthen ponds, at a density of 8 fish per m²; the rearing period was 60 days. Three different pond management were applied: limed and fertilized (LimFer), limed (Lim), and natural (Nat). Fish were fed with a commercial ration containing 34% crude protein three times daily. There were no significant differences in fish growth or yield. Three main items found in tambaqui stomach were insect, zooplankton and ration, without a significant difference among treatments in proportion. Alkalinity, hardness, and CO2 were greater in LimFer and Lim ponds. Chlorophyll a, transparency, ammonia, nitrite, temperature, and dissolved oxygen of pond water were not significantly different among treatments. Biochemical oxygen demand, total phosphorus, orthophosphate, ammonia, and nitrite were significantly greater in effluents from LimFer ponds. Pond fertilization should be avoided, because growth and yield were similar among the three pond management systems tested; besides, it produces a more impacting effluent.

Fifty years of wheat breeding in Southern Brazil: yield improvement and associated changes

The objective of this study was to assess the impact of genetic breeding on grain yield, and to identify the physiological traits associated to the increment in yield and their related growth processes, for wheat cultivars grown in Southern Brazil, in the past five decades. Seven wheat cultivars released between 1940 and 1992, were compared for physiological aspects associated with grain yield. Grain yield, biological yield, biomass partitioning, harvest index and grain yield components were also determined. The number of grains per square meter was more affected by plant breeding and was better correlated with grain yield (r = 0.94, p<0.01) than with grain weight (r = -0.39ns). The higher number of grains per square meter was better correlated with the number of grains per spike in the modern cultivars than in the older ones. The genetic gain in grain yield was 44.9 kg ha-1 per year, reflecting important efforts of the breeding programs carried out in Southern Brazil. Grain yield changes, during the period of study, were better associated with biomass production (r = 0.78, p<0.01) than with harvest index (r = 0.65, p<0.01).

Stringless Portland Cement Concrete Paving, TR-490, 2004

This report describes results from a study evaluating the use of stringless paving using a combination of global positioning and laser technologies. CMI and Geologic Computer Systems developed this technology and successfully implemented it on construction earthmoving and grading projects. Concrete paving is a new area for considering this technology. Fred Carlson Co. agreed to test the stringless paving technology on two challenging concrete paving projects located in Washington County, Iowa. The evaluation was conducted on two paving projects in Washington County, Iowa, during the summer of 2003. The research team from Iowa State University monitored the guidance and elevation conformance to the original design. They employed a combination of physical depth checks, surface location and elevation surveys, concrete yield checks, and physical survey of the control stakes and string line elevations. A final check on profile of the pavement surface was accomplished by the use of the Iowa Department of Transportation Light Weight Surface Analyzer (LISA). Due to the speed of paving and the rapid changes in terrain, the laser technology was abandoned for this project. Total control of the guidance and elevation controls on the slip-form paver were moved from string line to global positioning systems (GPS). The evaluation was a success, and the results indicate that GPS control is feasible and approaching the desired goals of guidance and profile control with the use of three dimensional design models. Further enhancements are needed in the physical features of the slipform paver oil system controls and in the computer program for controlling elevation.

Authentication of vegetable oils by bulk and molecular carbon isotope analyses with emphasis on olive oil and pumpkin seed oil

The authenticity of vegetable oils consumed in Slovenia and Croatia was investigated by carbon isotope analysis of the individual fatty acids by the use of gas chromatography-combustion-isotope ratio mass spectrometry (GC/C/IRMS), and through carbon isotope analysis of the bulk oil. The fatty acids from samples of olive, pumpkin, sunflower, maize, rape, soybean, and sesame oils were separated by alkaline hydrolysis and derivatized to methyl esters for chemical characterization by capillary gas chromatography/mass spectrometry (GC/MS) prior to isotopic analysis. Enrichment in heavy carbon isotope (C-13) of th, bulk oil and of the individual fatty acids are related to (1) a thermally induced degradation during processing (deodorization, steam washing, or bleaching), (2) hydrolytic rancidity (lipolysis) and oxidative rancidity of the vegetable oils during storage, and (3) the potential blend with refined oil or other vegetable oils. The impurity or admixture of different oils may be assessed from the delta C-13(16:0) VS. delta C-13(18:1) covariations. The fatty acid compositions of Slovenian and Croatian olive oils are compared with those from the most important Mediterranean producer countries (Spain, Italy, Greece, and France).

Effect of pruning on tree growth, yield, and wood properties of Tectona grandis plantations in Costa Rica

Abstract

Yield and fruit quality of apple from conventional and organic production systems

The objective of this study was to assess the yield and fruit quality of apple produced with a conventional and an organic production systems in Southern Brazil. The orchards consisted of alternate rows from 10 to 12-year old 'Royal Gala' and 'Fuji' apple trees on M.7 rootstocks, grown as slender spindles, on 4x6 m spacing. Eighteen apple trees of each cultivar and management system were randomly selected and assessed for nutrition, flowering, fruit set, yield, and fruit quality during two growing seasons (2002/2003 and 2003/2004). The organic management system resulted in lower concentrations of K, Mg, and N in leaves and fruits, and in smaller fruits for both cultivars, and lower fruit yield for 'Fuji' than from the conventional production system. For both cultivars, fruits from the organic orchard harvested at commercial maturity had a more yellowish skin background color, higher percentage of blush in the fruit skin, higher soluble solids content, higher density, higher flesh firmness, and higher severity of russet than fruits from the conventional orchard. Fruit from the organic orchard had lower titratable acidity in 'Royal Gala', and higher incidence of moldy core and lower incidence of watercore in 'Fuji', than fruit from the conventional orchard. A non-trained sensory panel detected no significant differences for fruit attributes of taste, flavor and texture between fruit from the production systems for either cultivar.

Red clover grown in a mixture with grasses : yield, persistence and dynamics of quality characteristics

Selostus: Puna-apilan pysyvyys apila-heinänurmessa sekä seosnurmen satoisuus ja laadun muutokset erilaisissa kasvuoloissa

Genetic control of grain yield and nitrogen use efficiency in tropical maize

The objectives of this work were to study the genetic control of grain yield (GY) and nitrogen (N) use efficiency (NUE, grain yield/N applied) and its primary components, N uptake efficiency (NUpE, N uptake/N applied) and N utilization efficiency (NUtE, grain yield/N uptake), in maize grown in environments with high and low N availability. Experiments with 31 maize genotypes (28 hybrid crosses and three controls) were carried out in soils with high and low N rates, in the southeast of the state of Minas Gerais, Brazil. There was a reduction of 23.2% in average GY for maize grown in soil with low N, in comparison to that obtained with high N. There were 26.5, 199 and 400% increases in NUtE, NUpE, and NUE, respectively, for maize grown with low N. The general combining ability (GCA) and specific combining ability (SCA) were significant for GY, NUE and NUpE for maize grown in high N soil. Only GCA was significant for NUpE for maize grown in low N soil. The GCA and SCA for NUtE were not significant in either environment. Additive and non-additive genetic effects are responsible for the genetic control of NUE and GY for maize grown in soils with high N availability, although additive effects are more important.

Unlike PAHs from Exxon Valdez crude oil, PAHs from Gulf of Alaska coals are not readily bioavailable.

In the wake of the 1989 Exxon Valdez oil spill, spatially and temporally spill-correlated biological effects consistent with polycyclic aromatic hydrocarbon (PAH) exposure were observed. Some works have proposed that confounding sources from local source rocks, prominently coals, are the provenance of the PAHs. Representative coal deposits along the southeast Alaskan coast (Kulthieth Formation) were sampled and fully characterized chemically and geologically. The coals have variable but high total organic carbon content technically classifying as coals and coaly shale, and highly varying PAH contents. Even for coals with high PAH content (approximately 4000 ppm total PAHs), a PAH-sensitive bacterial biosensor demonstrates nondetectable bioavailability as quantified, based on naphthalene as a test calibrant. These results are consistent with studies indicating that materials such as coals strongly diminish the bioavailability of hydrophobic organic compounds and support previous work suggesting that hydrocarbons associated with the regional background in northern Gulf of Alaska marine sediments are not appreciably bioavailable.

Soil compaction by machine traffic and least limiting water range related to soybean yield

The research aimed to evaluate machine traffic effect on soil compaction and the least limiting water range related to soybean cultivar yields, during two years, in a Haplustox soil. The six treatments were related to tractor (11 Mg weight) passes by the same place: T0, no compaction; and T1*, 1; T1, 1; T2, 2; T4, 4 and T6, 6. In the treatment T1*, the compaction occurred when soil was dried, in 2003/2004, and with a 4 Mg tractor in 2004/2005. Soybean yield was evaluated in relation to soil compaction during two agricultural years in completely randomized design (compaction levels); however, in the second year, there was a factorial scheme (compaction levels, with and without irrigation), with four replicates represented by 9 m² plots. In the first year, soybean [Glycine max (L.) Merr.] cultivar IAC Foscarim 31 was cultivated without irrigation; and in the second year, IAC Foscarim 31 and MG/BR 46 (Conquista) cultivars were cultivated with and without irrigation. Machine traffic causes compaction and reduces soybean yield for soil penetration resistance between 1.64 to 2.35 MPa, and bulk density between 1.50 to 1.53 Mg m-3. Soil bulk density from which soybean cultivar yields decrease is lower than the critical one reached at least limiting water range (LLWR =/ 0).

Toxicity of neem oil to Bemisia tabaci biotype B nymphs reared on dry bean

The objective of this work was to determine the most susceptible nymphal stage of Bemisia tabaci biotype B to neem (Azadirachta indica A. Juss.) oil applied to dry bean (Phaseolus vulgaris L.) in a screenhouse. A solution of commercial oil (Dalneem) extracted from neem seeds was sprayed directly on each nymphal instar at 0, 0.1, 0.25, 0.5, 1 and 2% concentrations for lethal concentration (LC) determination, and at 0, 0.5 and 1% concentrations for lethal time (LT) determination. The number of living and dead nymphs was recorded five days after spraying for LC determination, and daily during six days for LT determination. The LC50 estimated for fourth instar nymphs occurred at 0.56% concentration. For all instars, LC50 and LC95 were estimated at 0.32 and 2.78% concentrations, respectively. The estimated values of LT50 at 1% concentration were 2.46, 4.45, 3.02 and 6.98 days for the first to fourth instars, respectively. The LT50 occurred at five days for 0.5% and at four days for 1% concentration in all instars. A mortality rate of over 80% was observed on the 6th day for the first to third instars at 1% concentration. The first three nymphal stages were more susceptible to neem oil when compared to the fourth nymphal stage.