The Utilization of Agriculturally Derived Lignin as an Antioxidant in Asphalt Binder, TR-557, 2008

Oxidation is the primary cause of long-term aging in asphalt pavements. As a pavement oxidizes, it stiffens and can eventually crack. The use of an antioxidant as a performance enhancer in an asphalt binder could delay aging, thus increasing the life of an asphalt pavement. Lignin is a highly available and well-studied antioxidant. A wet-mill ethanol plant produces several co-products, some of which contain lignin. The use of lignin from ethanol production could provide a benefit to asphalt pavements and also give more value to the co-products. The following research examined the effects of lignin on asphalt pavements. Three lignin-containing co-products were separately combined with four asphalt binders in varying amounts to determine the optimum amount of co-product that would provide the greatest benefit to the asphalt binders. The asphalt binder and co-product blends were evaluated according to Superpave specifications and performance graded on a continuous scale. The data indicated a stiffening effect on the binder caused by the addition of the co-products. The more a co-product was added, the more a binder stiffened. Binder stiffening benefited the high temperature properties and the low temperature binder properties were negatively affected. However, the low temperature stiffening effects were small and in many cases not significant. The co-products had an overall effect of widening the temperature range of the binders. This result suggests some antioxidant activity between the binder and the lignin. Testing with a fourth co-product with no lignin supported the idea that lignin acts as an antioxidant. The samples with no lignin aged significantly more than the samples with lignin. Infrared spectrometry also supported the idea that lignin acts as an antioxidant by observing decreases in some oxidative aging products.

Sugarcane crop efficiency in two growing seasons in São Paulo State, Brazil

A conceptual framework for crop production efficiency was derived using thermodynamic efficiency concept, in order to generate a tool for performance evaluation of agricultural systems and to quantify the interference of determining factors on this performance. In Thermodynamics, efficiency is the ratio between the output and input of energy. To establish this relationship in agricultural systems, it was assumed that the input energy is represented by the attainable crop yield, as predicted through simulation models based on environmental variables. The method of FAO's agroecological zones was applied to the assessment of the attainable sugarcane yield, while Instituto Brasileiro de Geografia e Estatística (IBGE) data were used as observed yield. Sugarcane efficiency production in São Paulo state was evaluated in two growing seasons, and its correlation with some physical factors that regulate production was calculated. A strong relationship was identified between crop production efficiency and soil aptitude. This allowed inferring the effect of agribusiness factors on crop production efficiency. The relationships between production efficiency and climatic variables were also quantified and indicated that solar radiation, annual rainfall, water deficiency, and maximum air temperature are the main factors affecting the sugarcane production efficiency.

Sample size for full-sib family evaluation in sugarcane

The objective of this study was to determine the minimum number of plants per plot that must be sampled in experiments with sugarcane (Saccharum officinarum) full-sib families in order to provide an effective estimation of genetic and phenotypic parameters of yield-related traits. The data were collected in a randomized complete block design with 18 sugarcane full-sib families and 6 replicates, with 20 plants per plot. The sample size was determined using resampling techniques with replacement, followed by an estimation of genetic and phenotypic parameters. Sample-size estimates varied according to the evaluated parameter and trait. The resampling method permits an efficient comparison of the sample-size effects on the estimation of genetic and phenotypic parameters. A sample of 16 plants per plot, or 96 individuals per family, was sufficient to obtain good estimates for all traits considered of all the characters evaluated. However, for Brix, if sample separation by trait were possible, ten plants per plot would give an efficient estimate for most of the characters evaluated.

Leaf development and growth of selected sugarcane clones in a subtropical environment

The objective of this work was to compare phyllochron and leaf area on individual stalks of selected sugarcane (Saccharum officinarum) clones grown in a subtropical environment. A two-year field experiment was carried out in Santa Maria, RS, Brazil, during the 2007/2008 and 2008/2009 growing seasons. Three sugarcane clones were used: IAC 822045 (early), SP 711406 (median) and CB 4176 (late), in a complete randomized block design, with four replications. Expanded leaf and total leaf (tips) number were determined, and expanded leaf area was measured. The phyllochron (ºC day leaf-1) based on expanded and tip leaf number was estimated, using 10ºC as base temperature. Allometric relationships between individual area and number of expanded leaves were fitted. Phyllochron was analysed as a four-factor experiment: clone, growing season, phyllochron phase, and phyllochron type. The early clone had the greatest potential for growing in a subtropical climate because of higher leaf output and leaf area.

Spittlebug impacts on sugarcane quality and ethanol production

The objective of this work was to evaluate the impacts of spittlebug (Mahanarva fimbriolata) attack on sugarcane quality and ethanol production. Technological and microbiological parameters of juice and fermentation process were evaluated in ten fermentation cycles and two harvest seasons. Treatments consisted of different spittlebug stalk damage levels: control, with 100% of apparently healthy stalks; medium, with 15% of damaged or dry stalks (DDS); high, with 30% of DDS; and very high, with 60% of DDS. Spittlebug attack caused significant losses in cane quality, reducing total soluble solids, sucrose content, total reducing sugars, and pH, and increasing total phenolic compounds, and total and volatile juice acidity. The fermentation process was also significantly affected, resulting in lower ethanol content in wine. There was an increase in acetaldehyde concentration in the distillate. The spittlebug attack caused negative impacts on sugarcane quality and fermentation process, and these impacts are stronger in late season harvests.

Variabilidade genética de Sugarcane mosaic virus, causando mosaico em milho no Brasil

O objetivo deste trabalho foi caracterizar biológica e molecularmente três isolados de Sugarcane mosaic virus (SCMV) de lavouras de milho, analisá-los filogeneticamente e discriminar polimorfismos do genoma. Plantas com sintomas de mosaico e nanismo foram coletadas em lavouras de milho, no Estado de São Paulo e no Município de Rio Verde, GO, e seus extratos foliares foram inoculados em plantas indicadoras e submetidos à análise sorológica com antissoros contra o SCMV, contra o Maize dwarf mosaic virus (MDMV) e contra o Johnsongrass mosaic virus (JGMV). Mudas de sorgo 'Rio' e 'TX 2786' apresentaram sintomas de mosaico após a inoculação dos três isolados, e o DAS-ELISA confirmou a infecção pelo SCMV. O RNA total foi extraído e usado para amplificação por transcriptase reversa seguida de reação em cadeia de polimerase (RT-PCR). Fragmentos específicos foram amplificados, submetidos à análise por polimorfismo de comprimento de fragmento de restrição (RFLP) e sequenciados. Foi possível discriminar os genótipos de SCMV isolados de milho de outros isolados brasileiros do vírus. Alinhamentos múltiplos e análises dos perfis filogenéticos corroboram esses dados e mostram diversidade nas sequências de nucleotídeos que codificam para a proteína capsidial, o que explica o agrupamento separado desses isolados e sugere sua classificação como estirpes distintas, em lugar de simples isolados geográficos.

Resistance of sugarcane cultivars to Diatraea saccharalis

The objective of this work was to evaluate the oviposition preference of Diatraea saccharalis and the effect of ten sugarcane cultivars on larval development. Oviposition preference was assessed under greenhouse conditions by three releases of couples of moths, with subsequent counting of egg masses and eggs per plant. In order to evaluate the effect of the cultivars on larval development, each plant was infected with about 150 eggs, and, 29 days later, the total number of internodes, number of bored internodes, number of life forms found, larval and pupal weight and length, and the width of larval head capsule were evaluated. The cultivars IACSP94-2101 and IACSP96-2042, the least preferred by D. saccharalis for oviposition, and IACSP94-2094, the most unfavorable for larvae entrance and development, show resistance to the pest.

Spatio-temporal variability of sugarcane yield efficiency in the state of São Paulo, Brazil

The objective of this work was to assess the spatial and temporal variability of sugarcane yield efficiency and yield gap in the state of São Paulo, Brazil, throughout 16 growing seasons, considering climate and soil as main effects, and socioeconomic factors as complementary. An empirical model was used to assess potential and attainable yields, using climate data series from 37 weather stations. Soil effects were analyzed using the concept of production environments associated with a soil aptitude map for sugarcane. Crop yield efficiency increased from 0.42 to 0.58 in the analyzed period (1990/1991 to 2005/2006 crop seasons), and yield gap consequently decreased from 58 to 42%. Climatic factors explained 43% of the variability of sugarcane yield efficiency, in the following order of importance: solar radiation, water deficit, maximum air temperature, precipitation, and minimum air temperature. Soil explained 15% of the variability, considering the average of all seasons. There was a change in the correlation pattern of climate and soil with yield efficiency after the 2001/2002 season, probably due to the crop expansion to the west of the state during the subsequent period. Socioeconomic, biotic and crop management factors together explain 42% of sugarcane yield efficiency in the state of São Paulo.

Correlation of physical and chemical attributes of soil with sugarcane yield

The objective of this work was to evaluate the correlation between sugarcane yield and some physical and chemical attributes of soil. For this, a 42‑ha test area in Araras, SP, Brazil, was used. Soil properties were determined from samples collected at the beginning of the 2003/2004 harvest season, using a regular 100x100 m grid. Yield assessment was done with a yield monitor (Simprocana). Correlation analyses were performed between sugarcane yield and the following soil properties: pH, pH CaCl2, N, C, cone index, clay content, soil organic matter, P, K, Ca, Mg, H+AL, cation exchange capacity, and base saturation. Correlation coefficients were respectively ‑0.05, ‑0.29, 0.33, 0.41, ‑0.27, 0.22, 0.44, ‑0.24, trace, ‑0.06, 0.01, 0.32, 0.14, and 0.04. Correlations of chemical and physical attributes of soil with sugarcane yield are weak, and, per se, they are not able to explain sugarcane yield variation, which suggests that other variables, besides soil attributes, should be analysed.

Stalk and sucrose yield in response to nitrogen fertilization of sugarcane under reduced tillage

The objective of this work was to evaluate the agroindustrial production of sugarcane (millable stalks and sucrose yield) after successive nitrogen fertilizations of plant cane and ratoons in a reduced tillage system. The experiment was carried out at Jaboticabal, SP, Brazil, on a Rhodic Eutrustox soil, during four consecutive crop cycles (March 2005 to July 2009). Plant cane treatments consisted of N-urea levels (control, 40, 80, and 120 kg ha-1 N + 120 kg ha-1 P2O5 and K2O in furrow application). In the first and second ratoons, the plant cane plots were subdivided in N-ammonium nitrate treatments (control, 50, 100, and 150 kg ha-1 N + 150 kg ha-1 K2O as top dressing over rows). In the third ratoon, N fertilization was leveled to 100 kg ha-1 in all plots, including controls, to detect residual effects of previous fertilizations on the last crop's cycle. Sugarcane ratoon was mechanically harvested. A weighing truck was used to evaluate stalk yield (TCH), and samples were collected in the field for analysis of sugar content (TSH). Increasing N doses and meteorological conditions promote significant responses in TCH and TSH in cane plant and ratoons, in the average and accumulated yield of the consecutive crop cycles.

Survival of sugarcane shoot tips after cryopreservation by droplet-vitrification

The objective of this work was to evaluate the phytotoxicity of a plant vitrification solution (PVS2), and the survival of shoot tips of the sugarcane variety SP716949, after cryopreservation by droplet-vitrification. Shoot tips were precultured for 24 hours in MS medium containing 0.3 mol L-1 sucrose, and exposed to PVS2 for 0, 20 or 30 min. Shoot tips were then immersed in liquid nitrogen. Thawing was fast in concentrated sucrose solution (1.2 mol L-1). PVS2 is a nontoxic to shoot tips, which in turn are sensitive to liquid nitrogen. The best results occurred when shoot tips were maintained for up to 20 min in PVS2 solution, before freezing, with 20% survival.

Protein contamination on Klason lignin contents in tropical grasses and legumes

The objective of this work was to evaluate the extent of protein contamination on Klason lignin (KL) in tropical grasses and legumes, and to propose an equation to estimate the protein-free content of Klason lignin (KLp). Five grass (30 samples) and 12 legume species (31 samples) were evaluated. Legumes had higher KL contents. Protein contamination was significant in both grasses and legumes, but greater in legume samples. The model to predict KLp was based on KL and crude protein (CP) contents, as follows: KLp = 0.8807KL - 0.0938KL x D - 0.00338CP (R2=0.935), in which D=0, for grasses, and D=1 for legumes.

Sugarcane response to nitrogen rates, measured by a canopy reflectance sensor

Abstract:The objective of this work was to evaluate whether a canopy sensor is capable of estimating sugarcane response to N, as well as to propose strategies for handling the data generated by this device during the decision-making process for crop N fertilization. Four N rate-response experiments were carried out, with N rates varying from 0 to 240 kg ha-1. Two evaluations with the canopy sensor were performed when the plants reached average stalk height of 0.3 and 0.5 m. Only two experiments showed stalk yield response to N rates. The canopy sensor was able to identify the crop response to different N rates and the relationship of the nutrient with sugarcane yield. The response index values obtained from the canopy sensor readings were useful in assessing sugarcane response to the applied N rate. Canopy reflectance sensors can help to identify areas responsive to N fertilization and, therefore, improve sugarcane fertilizer management.

Characterization and drying of caja bagasse (Spondias mombin L.) in a tray dryer using a factorial planning

The caja (Spondias mombin L.) is used in the manufacture of ice-cream, jams, pulps, beverages being also consumed in natura. One of the most important procedures in food conservation is drying, considering that most fresh fruits contain approximately 80% of water. Food drying is used to obtain two basic aspects: (1) the economic factor; in the shipping and handling of the product; (2) at the manipulation; once dried and grinded, the material is rehydrated, at desirable levels, to formulate a new product as in ice cream, jams, yoghurts and drinks and may also be added to pasta, biscuits and other industrialized products. The aim of this study was to investigate the kinetics of caja bagasse drying in a fixed-bed tray dryer, using central composite factorial planning. The following factors were evaluated: temperature (55, 65 and 75 ºC), dryer inlet air velocity (3.2, 4.6 and 6.0 m.s-1) and cake thickness (0.8, 1.2 and 1.6 cm) where the response of the considered variable was caja bagasse moisture content (b.s.) and the results showed that the main effects and their interactions were significant at a 95% confidence level being the best condition obtained at temperature of 75 ºC, velocity of 6.0 m.s-1 and cake thickness of 0.8 cm.