Effect of post-emergent herbicides application on carotenoid concentration in green corn.

Considering the influence of herbicides in the metabolism of the carotenoids in corn, the objective of the present study was to evaluate the effect of herbicides and genotype on carotenoids concentration. The green corn hybrids BRS 1030 and P30F53 were subjected to a post-emergent herbicides application at 20 and 30 days after emergence. Carotenoids were extracted from corn grains and analyzed to quantify ?- and ?-carotene, lutein, zeaxanthin, ?-cryptoxanthin, total carotenoids (TC), and total of vitamin A carotenoids precursors (proVA). The application of foramsulfuron + iodosulfuron-methyl-sodium (40 + 2.6 g ha-1), nicosulfuron (20 g ha-1), mesotrione (120 g ha-1) and tembotrione (80 g ha-1 and 100 g ha-1) promoted higher concentration of carotenoids in fresh green corn. Lutein, zeaxanthin, ?-cryptoxanthin, ?-carotene, ?-carotene, proVA carotenoids, and TC concentration increased after foramsulfuron + iodosulfuron-methyl-sodium in late application (V5 to V6), nicosulfuron in both applications, mesotrione applied post-initial (V3 to V4), tembotrione (100 g ha-1) in both applications and tembotrione (80 g ha-1) in late post-application, at least for one hybrid. The content of carotenoids in the green corn kernels differed between ?BRS 1030? and ?P30F53?. Our results suggest a possibility of significant increase of carotenoids in green corn kernels through the handling of corn production with post-emergent herbicides.

Use of organic compost containing waste from small ruminants in corn production.

Composting is a useful way of transforming livestock waste into organic fertilizer, which is proven to increase soil nutrient levels, and thus crop yield. Remains from production and slaughter of small ruminants can become a source of important elements for plant growth, such as N, after microorganism-driven decomposition.The aim of this investigation was to evaluate the effects of this compost on soil fertility and on the nutritional status and yield of the corn crop. The experiment was conducted in a Haplic Luvisol in a randomized block design with six treatments and five application rates of the organic compound in Mg ha-1: 3 (half the standard rate), 6 (standard rate), 9 (one and a half times the standard rate), 12 (twice the standard rate), and 24 (four times the standard rate) and an additional treatment with mineral fertilizers (110, 50 e 30 kg ha-1 of N, P2O5 and K2O, respectively), with four blocks. Evaluations were performed for two harvests of rainfed crops, measuring soil fertility, nutritional status, and grain yield. The compost increased P, K, Na and Zn values in the 0.00-0.20 m layer in relation of mineral fertilization in 616, 21, 114 and 90 % with rate 24 Mg ha-1 in second crop. Leaf N, Mg, and S contents, relative chlorophyll content, and the productivity of corn kernels increased in 27, 32, 36, 20 e 85 %, respectively, of low rate (3 Mg ha-1) to high rate (24 Mg ha-1) with of application of the compost. Corn yield was higher with application of organic compost in rate of 24 Mg ha-1 than mineral fertilizer combination in second crop.

Nitrogen oxides and CO2 from an Oxisol cultivated with corn in succession to cover crops.

2016

Soil microbilogica properties and available nitrogen for corn in monoculture and intercropped with forage.

2016

Effect of acid alcoholic solution in waxy maize starch treatment.

O amido é o polissacarídeo mais abundante presente em plantas, composto por amilose e amilopectina. O amido de milho ceroso apresenta somente amilopectina. A modificação do amido é recomendada para melhorar suas aplicações. A hidrólise ácida é utilizada para alterar as propriedades físico-químicas sem modificar o grânulo e o meio alcoólico ajuda na recuperação da molécula após o tratamento. O objetivo do trabalho foi o tratamento químico com HCl 0,5 mol L-1 durante 1 hora em 100 ml de água, etanol ou metanol. Os equipamentos SETSYS Evolução TGADTA / DSC e Rápido Visco-Analisador (RVA-4) foram usados para avaliar as alterações dos amidos. As curvas TG mostraram três eventos (desidratação, estabilidade e decomposição), com resultados similares para todas as amostras. Este resultado pode estar relacionado a resistência da amilopectina para a hidrólise ácida. Na análise reológica (RVA) o tratamento das amostras mostrou valores mais baixos de perfis de viscosidade. A solução ácida forneceu mudanças nas propriedades de pasta do amido e a solução etanólica (solvente mais apolar) foi maior que as demais soluções. Conclui-se portanto que o tratamento dos amidos forneceu produtos com características térmicas similares e com diferentes respostas mecânicas

Effect of the KMnO4 Treatment on the "pinhão" starch.

O pinhão, sementes de Araucaria angustifolia, tem o amido como componente principal. Os amidos oxidados melhoram as características físico-química, de pasta e térmicas dos produtos em processos industriais. O amido de pinhão nativo foi tratado com soluções padronizadas de permanganato de potássio (KMnO4) e as amostras foram analisadas por técnicas termoanalíticas (TG-DTA) em atmosfera inerte. As amostras foram oxidadas da seguinte forma: quatro porções de 20 g (base seca) foram separadas e três foram suspensas em solução de KMnO4 (0,001; 0,002; 0,005 mol L-1) em agitação constante durante 30 minutos, a quarta amostra foi mantida como recebida. As suspensões de amido foram filtradas, lavadas, secas e analisadas. As modificações oxidativas provocaram mudanças estruturais das moléculas de amido, registradas pelos diferentes resultados calculados a partir das curvas TGA e DTA. A amostra (3) teve as mudanças mais significativas na degradação com o 3ª evento exotérmico com temperaturas acima de 330 °C.

Evaluation of double treated starches using thermal tools.

Starch is the main polysaccharide found in cereals, composed by amylose and amylopectin. Corn is the principal source of starches worldwide. Starches treatment, through physical, chemical and/or biological methods, can improve the applications range. Acid modification in alcoholic solution promotes minimally degradation in the granule. Ball mill is one physical method poorly explored. The aim was to treat the starches using HCl 0.5 mol L-1 for 1 hour in 100 ml of aqueous, ethanol or methanol solutions with subsequent ball milling processes. One sample was selected as native sample. The four others, one native sample and three acid modified samples, were treated by physical process with the oscillating ball mill. The DTG-60H equipment was used for the TG and DTA analysis. The TG curves showed three mass losses related to dehydration, decomposition and oxidation. The native sample without physical modification showed major resistance to total degradation. This occurs because the physical modification cleaves hydrogen bonds, leaving a weakened granule. The TGDTA results showed that the mass loss in the 2nd event was minor in the hydrolyzed samples compared with native samples. The acid modification can provide starch higher resistance to degradation up to 340 °C. These results showed that chemical and physical treatment changed the thermal behaviors of the starches.

THERMOGRAVIMETRIC ALTERATIONS OF CASSAVA STARCH GRANULES INDUCED BY HYDROGEN PEROXIDE, UV RAYS AND MICROWAVE

Starches are applied in several fields of industry. Amylose and amylopectin (natural polymers) constitute the starch in vegetable cells. In some processes native starches cannot support high stress conditions (high temperatures/acidity). Then, modification methods are developed aiming the improving of starch technological utilization. Oxidative modification with H2O2 has been the subject of many researches. UV rays as well microwave irradiation can be used. The aim was to confirm possible thermogravimetric alterations in native cassava starch (A) granules due to a double starch modification: 1st step) H2O2 standard solutions 0.1 mol L-1 (B), 0.2 mol L-1 (C) and 0.3 mol L-1 (D) and UV rays exposure for 1h; 2nd step) microwave irradiation for 5 min. The results of thermogravimetric curves (TG-DTA) show that the behaviors of the starch proprieties were modified. Highlighting, the modified samples C and D showed a decrease on the thermal stability step. This alteration turned them suitable to many field of industry like the paper one.

Combined effects of soil biotic and abiotic factors, influenced by sewage sludge incorporation, on the incidence of corn stalk rot.

Abstract: The objectives of this study were to evaluate the combined effects of soil bioticand abiotic factors on the incidence of Fusarium corn stalk rot, during four annual incorporations of two typesofsewagesludge intosoil ina 5-years field assay under tropical conditions and topredict the effectsof these variables on the disease. For each type of sewage sludge, the following treatments were included: control with mineral fertilization recommended for corn; control without fertilization; sewage sludge based on the nitrogen concentration that provided the same amount of nitrogen as in the mineral fertilizer treatment; and sewage sludge that provided two, four and eight times the nitrogen concentration recommended for corn. Increasing dosages of both types of sewage sludge incorporated into soil resulted in increased corn stalk rot incidence, being negatively correlated with corn yield. A global analysis highlighted the effect of the year of the experiment, followed by the sewage sludge dosages. The type of sewage sludge did not affect the disease incidence. Amultiple logistic model using a stepwise procedure was fitted based on the selection of a model that included the three explanatory parameters for disease incidence: electrical conductivity, magnesium and Fusarium population. In the selected model, the probability of higher disease incidence increased with an increase of these three explanatory parameters. When the explanatory parameters were compared, electrical conductivity presented a dominant effect and was the main variable to predict the probability distribution curves of Fusarium corn stalk rot, after sewage sludge application into the soil.

Apparent digestibility of selected feed ingredients in diets formulated for the sub-adult mud crab, Scylla paramamosain, in Vietnam

The present study was conducted to explore the potential to incorporate local plant-based feed ingredients into diets formulated for the mud crab species, Scylla paramamosain, commonly exploited for aquaculture in South-east Asia. Four test ingredients (defatted soybean meal, rice bran, cassava meal and corn flour) were incorporated at 30% or 45% inclusion levels in a fishmeal-based reference diet and used in digestibility trials where apparent digestibility coefficients (ADCs) for experimental diets and test ingredients were determined. Generally, high ADC values were obtained using diets containing 30% soybean meal or rice bran. By contrast, the lowest ADC values were obtained for the diet containing 45% cassava meal [70.9% for dry matter (ADMD); 77.1% for crude protein (ACPD) and 80.2% for gross energy (AGED)]. Similar trends were observed when ADC ingredient (I) digestibilities were compared. Specifically, the highest ADCI values were obtained for soybean meal when used at a 30% inclusion level (87.6% ADMDI; 98.4% ACPDI and 95.6% AGEDI) while the lowest ADCI values were obtained using cassava meal at a 45% inclusion level (53.8% ADMDI; 60.2% ACPDI and 67.3% AGEDI). Based on the current findings, we propose that soybean meal and rice bran could be considered for incorporation into formulated diets for S. paramamosain.

Infrared spectroscopic investigation of the effects of titania photocatalyst on the degradation of linear low density polyethylene film for commercial applications

There is a need in industry for a commodity polyethylene film with controllable degradation properties that will degrade in an environmentally neutral way, for applications such as shopping bags and packaging film. Additives such as starch have been shown to accelerate the degradation of plastic films, however control of degradation is required so that the film will retain its mechanical properties during storage and use, and then degrade when no longer required. By the addition of a photocatalyst it is hoped that polymer film will breakdown with exposure to sunlight. Furthermore, it is desired that the polymer film will degrade in the dark, after a short initial exposure to sunlight. Research has been undertaken into the photo- and thermo-oxidative degradation processes of 25 ìm thick LLDPE (linear low density polyethylene) film containing titania from different manufacturers. Films were aged in a suntest or in an oven at 50 °C, and the oxidation product formation was followed using IR spectroscopy. Degussa P25, Kronos 1002, and various organic-modified and doped titanias of the types Satchleben Hombitan and Hunstsman Tioxide incorporated into LLDPE films were assessed for photoactivity. Degussa P25 was found to be the most photoactive with UVA and UVC exposure. Surface modification of titania was found to reduce photoactivity. Crystal phase is thought to be among the most important factors when assessing the photoactivity of titania as a photocatalyst for degradation. Pre-irradiation with UVA or UVC for 24 hours of the film containing 3% Degussa P25 titania prior to aging in an oven resulted in embrittlement in ca. 200 days. The multivariate data analysis technique PCA (principal component analysis) was used as an exploratory tool to investigate the IR spectral data. Oxidation products formed in similar relative concentrations across all samples, confirming that titania was catalysing the oxidation of the LLDPE film without changing the oxidation pathway. PCA was also employed to compare rates of degradation in different films. PCA enabled the discovery of water vapour trapped inside cavities formed by oxidation by titania particles. Imaging ATR/FTIR spectroscopy with high lateral resolution was used in a novel experiment to examine the heterogeneous nature of oxidation of a model polymer compound caused by the presence of titania particles. A model polymer containing Degussa P25 titania was solvent cast onto the internal reflection element of the imaging ATR/FTIR and the oxidation under UVC was examined over time. Sensitisation of 5 ìm domains by titania resulted in areas of relatively high oxidation product concentration. The suitability of transmission IR with a synchrotron light source to the study of polymer film oxidation was assessed as the Australian Synchrotron in Melbourne, Australia. Challenges such as interference fringes and poor signal-to-noise ratio need to be addressed before this can become a routine technique.

Market access of Papua New Guinea bananas (Musa spp.) with particular respect to banana fly (Bactrocera musae (Tryon)) (Diptera: Tephritidae)

International market access for fresh commodities is regulated by international accepted phytosanitary guidelines, the objectives of which are to reduce the biosecurity risk of plant pest and disease movement. Papua New Guinea (PNG) has identified banana as a potential export crop and to help meet international market access requirements, this thesis provides information for the development of a pest risk analysis (PRA) for PNG banana fruit. The PRA is a three step process which first identifies the pests associated with a particular commodity or pathway, then assesses the risk associated with those pests, and finally identifies risk management options for those pests if required. As the first step of the PRA process, I collated a definitive list on the organisms associated with the banana plant in PNG using formal literature, structured interviews with local experts, grey literature and unpublished file material held in PNG field research stations. I identified 112 organisms (invertebrates, vertebrate, pathogens and weeds) associated with banana in PNG, but only 14 of these were reported as commonly requiring management. For these 14 I present detailed information summaries on their known biology and pest impact. A major finding of the review was that of the 14 identified key pests, some research information occurs for 13. The single exception for which information was found to be lacking was Bactrocera musae (Tryon), the banana fly. The lack of information for this widely reported ‘major pest on PNG bananas’ would hinder the development of a PNG banana fruit PRA. For this reason the remainder of the thesis focused on this organism, particularly with respect to generation of information required by the PRA process. Utilising an existing, but previously unanalysed fruit fly trapping database for PNG, I carried out a Geographic Information System analysis of the distribution and abundance of banana in four major regions of PNG. This information is required for a PRA to determine if banana fruit grown in different parts of the country are at different risks from the fly. Results showed that the fly was widespread in all cropping regions and that temperature and rainfall were not significantly correlated with banana fly abundance. Abundance of the fly was significantly correlated (albeit weakly) with host availability. The same analysis was done with four other PNG pest fruit flies and their responses to the environmental factors differed to banana fly and each other. This implies that subsequent PRA analyses for other PNG fresh commodities will need to investigate the risk of each of these flies independently. To quantify the damage to banana fruit caused by banana fly in PNG, local surveys and one national survey of banana fruit infestation were carried out. Contrary to expectations, infestation was found to be very low, particularly in the widely grown commercial cultivar, Cavendish. Infestation of Cavendish fingers was only 0.41% in a structured, national survey of over 2 700 banana fingers. Follow up laboratory studies showed that fingers of Cavendish, and another commercial variety Lady-finger, are very poor hosts for B. musae, with very low host selection rates by female flies and very poor immature survival. An analysis of a recent (within last decade) incursion of B. musae into the Gazelle Peninsula of East New Britain Province, PNG, provided the final set of B. musae data. Surveys of the fly on the peninsular showed that establishment and spread of the fly in the novel environment was very rapid and thus the fly should be regarded as being of high biosecurity concern, at least in tropical areas. Supporting the earlier impact studies, however, banana fly has not become a significant banana fruit problem on the Gazelle, despite bananas being the primary starch staple of the region. The results of the research chapters are combined in the final Discussion in the form of a B. musae focused PRA for PNG banana fruit. Putting the thesis in a broader context, the Discussion also deals with the apparent discrepancy between high local abundance of banana fly and very low infestation rates. This discussion focuses on host utilisation patterns of specialist herbivores and suggests that local pest abundance, as determined by trapping or monitoring, need not be good surrogate for crop damage, despite this linkage being implicit in a number of international phytosanitary protocols.

Nitrogen fertilizer rate management as a nitrous oxide mitigation strategy: Development of a nitrous oxide emission reduction protocol (NERP)

Nitrous oxide (N2O) is a potent agricultural greenhouse gas (GHG). More than 50% of the global anthropogenic N2O flux is attributable to emissions from soil, primarily due to large fertilizer nitrogen (N) applications to corn and other non-leguminous crops. Quantification of the trade–offs between N2O emissions, fertilizer N rate, and crop yield is an essential requirement for informing management strategies aiming to reduce the agricultural sector GHG burden, without compromising productivity and producer livelihood. There is currently great interest in developing and implementing agricultural GHG reduction offset projects for inclusion within carbon offset markets. Nitrous oxide, with a global warming potential (GWP) of 298, is a major target for these endeavours due to the high payback associated with its emission prevention. In this paper we use robust quantitative relationships between fertilizer N rate and N2O emissions, along with a recently developed approach for determining economically profitable N rates for optimized crop yield, to propose a simple, transparent, and robust N2O emission reduction protocol (NERP) for generating agricultural GHG emission reduction credits. This NERP has the advantage of providing an economic and environmental incentive for producers and other stakeholders, necessary requirements in the implementation of agricultural offset projects.

Expression Pattern of the Alpha-Kafirin Promoter Coupled with a Signal Peptide from Sorghum bicolor L. Moench

Regulatory sequences with endosperm specificity are essential for foreign gene expression in the desired tissue for both grain quality improvement and molecular pharming. In this study, promoters of seed storage α-kafirin genes coupled with signal sequence (ss) were isolated from Sorghum bicolor L. Moench genomic DNA by PCR. The α-kafirin promoter (α-kaf) contains endosperm specificity-determining motifs, prolamin-box, the O2-box 1, CATC, and TATA boxes required for α-kafirin gene expression in sorghum seeds. The constructs pMB-Ubi-gfp and pMB-kaf-gfp were microprojectile bombarded into various sorghum and sweet corn explants. GFP expression was detected on all explants using the Ubi promoter but only in seeds for the α-kaf promoter. This shows that the α-kaf promoter isolated was functional and demonstrated seed-specific GFP expression. The constructs pMB-Ubi-ss-gfp and pMB-kaf-ss-gfp were also bombarded into the same explants. Detection of GFP expression showed that the signal peptide (SP)::GFP fusion can assemble and fold properly, preserving the fluorescent properties of GFP.

The composition of sugarcane juices dervied from burnt cane and whole green cane crop

There has been substantial interest within the Australian sugar industry in product diversification as a means to reduce its exposure to fluctuating raw sugar prices and in order to increase its commercial viability. In particular, the industry is looking at fibrous residues from sugarcane harvesting (trash) and from sugarcane milling (bagasse) for cogeneration and the production of biocommodities, as these are complementary to the core process of sugar production. A means of producing surplus residue (biomass) is to process whole sugarcane crop. In this paper, the composition of different juices derived from different harvesting methods, viz. burnt cane with all trash extracted (BE), green cane with half of the trash extracted (GE), and green cane (whole sugarcane crop) with trash unextracted (GU), were investigated and the results and comparison presented. The determination of electrical conductivity, inorganic composition, and organic acids indicate that both GU and GE cane juice contain a higher proportion of soluble inorganic ions and ionisable organic acids, compared to BE cane juice. It is important to note that there are considerably higher levels of Na ions and citric acid, but relatively low P levels in the GU samples. A higher level of reducing sugars was analysed in the GU samples than the BE samples due to the higher proportion of impurities found naturally in sugarcane tops and leaves. The purity of the first expressed juice (FEJ) of GU cane was on average higher than that of FEJ of BE cane. Results also show that GU juices appear to contain higher levels of proteins and polysaccharides, with no significant difference in starch levels.