967 resultados para Traditional maize production
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An updated empirical approach is proposed for specifying coexistence requirements for genetically modified (GM) maize (Zea mays L.) production to ensure compliance with the 0.9% labeling threshold for food and feed in the European Union. The model improves on a previously published (Gustafson et al., 2006) empirical model by adding recent data sources to supplement the original database and including the following additional cases: (i) more than one GM maize source field adjacent to the conventional or organic field, (ii) the possibility of so-called “stacked” varieties with more than one GM trait, and (iii) lower pollen shed in the non-GM receptor field. These additional factors lead to the possibility for somewhat wider combinations of isolation distance and border rows than required in the original version of the empirical model. For instance, in the very conservative case of a 1-ha square non-GM maize field surrounded on all four sides by homozygous GM maize with 12 m isolation (the effective isolation distance for a single GM field), non-GM border rows of 12 m are required to be 95% confident of gene flow less than 0.9% in the non-GM field (with adventitious presence of 0.3%). Stacked traits of higher GM mass fraction and receptor fields of lower pollen shed would require a greater number of border rows to comply with the 0.9% threshold, and an updated extension to the model is provided to quantify these effects.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The aim of the work was to evaluate soil nutrient concentration at 0-5, 5-10, and 10-20 cm in maize (Zea mays L.) grown in sequence with black oats (Avena strigosa Schreb.) under Leucaena diversifolia alley cropping agroforestry system (AFS) and traditional management system/sole crop (without trees-TS), following a randomized block design. The experiment was carried out at the Brazilian Association of Biodynamic Agriculture, in Botucatu, São Paulo, Brazil. The treatments were: control (C), chemical fertilizer (F), biomass of L. diversifolia alley cropping (B), and biomass of L. diversifolia alley cropping + chemical fertilizer (B+F). After 2 yr, it was observed that pH, organic matter, and nutrient content had a tendency to show higher values in the treatments biomass+fertilizer, biomass, and fertilizer application, in both systems. Higher values in pH, organic matter, phosphorus, potassium, calcium, magnesium, sum of bases, cation exchange capacity, percentage base saturation, boron, copper, and manganese tended to occur in the agroforestry system. © 2013 Copyright Taylor and Francis Group, LLC.
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Until 1990, beef cattle production in Brazil was recognized as an enterprise of low investment, low cost of production, as well as an extensive production system that used large land areas to be economically feasible. The situation changed for the Brazilian beef market when the economy stabilized in 1994 and all sectors involved in the beef supply chain were able to predict their associated costs and profits. During the same period, purchasing power of the Brazilian population grew, and as a consequence, consumers began to demand higher quality beef products. This new scenario in the late 1990s and early 2000s has led to more intensive beef production systems in Brazil as well as the need for a greater understanding of how technologies might be applied. As consequence of this evolution, in the last five years, a necessity to increase beef production has occurred. The quality of Brazilian beef has improved compared with beef produced 15 years ago, but continued improvements are needed to achieve excellence in terms of large-scale production of high quality beef, be sustainable over a long period of time, and increase our contribution to global food security.
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In Maize (Zea maize L.), cost of hybrid seed production is directly related to the yield and quality of seed obtained per hectare of female parent. It is also important to consider the effects that a male parent can exert on the development of hybrid seed in the female parent. This effect is known as xenia. The objectives of this study were to evaluate xenia effects on 1) yield as 80K units, 2) germination of the hybrid seed and 3) susceptibility of the hybrid seed to mechanical damage. One female inbred and four male inbred lines were selected from a parent list of hybrids. The experiment was designed to allow individual cross pollination between each male inbred and the female inbred line. For use as a control, the female inbred was allowed to self pollinate. Experiments were conducted in Illinois and Iowa during 2008 and 2009 and in Nebraska during 2009. A significant inbred effect was detected on yield as 80k (α=0.001). The selfed female and pollination with male inbred B resulted in lower yields of hybrid seed. For germination, a significant inbred effect was detected (α=0.001), but was due to lower germination percentage of seed produced on the selfed female. All hybrid combinations resulted in higher germination percentages with no significant differences among hybrids. The inbred x mechanical damage interaction was significant (P=0.04) for effects on cold saturated soil germination tests. Use of inbred B resulted in a two-percentage-point reduction in cold germination when treated with the impact simulator. In a maize seed company, the production research group provides yield estimates for production of new hybrid combinations. Results from this study indicate that using only the female inbred yield may provide inaccurate estimates. Therefore to improve yield estimation, experiments should be designed to include male inbreds. Male inbreds can also impart a negative effect to the hybrid seed on tolerance to mechanical damage, thus lowering quality and increasing seed discard. When testing for hybrid seed germination, there is no need to consider distinct hybrid combinations. Female inbreds can be grown in open-pollinated fields to avoid loss of vigor observed with selfing. Advisor: George Graef
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Strain ST211CH, identified as a strain of Enterococcus faecium, isolated from Lombo produced a bacteriocin that inhibited the growth of Enterococcus spp., Listeria spp., Klebsiella spp., Lactobacillus spp., Pseudomonas spp., Staphylococcus spp. and Streptococcus spp. The mode of action of the bacteriocin named as bacteriocin ST211Ch was bactericidal against Enterococcus faecalis ATCC19443. As determined by Tricine-SDS-PAGE, the approximate molecular mass of the bacteriocin was 8.0 kDa. Loss in antimicrobial activity was recorded after treatment with proteolytic enzymes. Maximum activity of bacteriocin ST211Ch was measured in broth cultures of E. faecium strain ST211Ch after 24 h; thereafter, the activity was reduced. Bacteriocin ST211Ch remained active after exposure to various temperatures and pHs, as well as to Triton X-100, Tween-80, Tween-20, sodium dodecyl sulfate, NaCl, urea and EDTA. Effect of media components on production of bacteriocin ST211Ch was also studied. On the basis of PCR reactions targeting different bacteriocin genes, i.e. enterocins, curvacins and sakacins, no evidences for the presence of these genes in the total DNA of E. faecium strain ST211Ch was obtained. The bacterium most probably produced a bacteriocin different from those mentioned above. Based on the antimicrobial spectrum, stability and mode of action of bacteriocin ST211CH, E. faecium strain ST211Ch might be considered as a potential candidate with beneficial properties for use in biopreservation to control food spoilage bacteria.
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The adoption of no-till system (NTS) combined with crop-livestock integration (CLI) has been a strategy promoted in Brazil, aiming to maximize areas yield and increase agribusiness profitability. This study aimed to evaluate grains yield and phytotechnical attributes from maize and soybean culture by CLI system under NTS after winter annual pure and diversified pastures with the absence or presence of grazing animals. The experiment was installed in Castro (Parana State, Brazil) on in a dystrophic Humic Rhodic Hapludox with a clay texture, using experimental design of randomized complete blocks in 4 x 2 factorial scheme with three replications. Treatments included four pasture combinations (diversified or pure) and animal categories (light and heavy) subjected or not to grazing animals during the winter. During 2008/09 and 2009/10 summers, the area was cultivated with soybeans and maize, respectively, with yield assessment of grains and phytotechnical attributes. Treatments did not alter the yield and weight of a thousand seeds (WTS) of soybeans. In maize culture, the grazing animal during the winter increased the plant population and grains yield, but gave slight decrease in WTS. Pasture combinations (diversified or pure) and animal categories (light and heavy) did not interfere in soybean culture, but benefited the maize crop.
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Small-scale farmers in the Chipata District of Zambia rely on their farm fields to grow maize and groundnuts for food security. Cotton production and surplus food security crops are used to generate income to provide for their families. With increasing population pressure, available land has decreased and farmers struggle to provide the necessary food requirements and income to meet their family’s needs. The purpose of the study was to determine how a farmer can best allocate his land to produce maize, groundnuts and cotton when constrained by labor and capital resources to generate the highest potential for food security and financial gains. Data from the 2008-2009 growing season was compiled and analyzed using a linear programming model. The study determined that farmers make the most profit by allocating all additional land and resources to cotton after meeting their minimum food security requirements. The study suggests growing cotton is a beneficial practice for small-scale subsistence farmers to generate income when restricted by limited resources.
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Fatty acid derivatives are of central importance for plant immunity against insect herbivores; however, majorregulatory genes and the signals that modulate these defense metabolites are vastly understudied, especiallyin important agro-economic monocot species. Here we show that products and signals derived from a singleZea mays (maize) lipoxygenase (LOX), ZmLOX10, are critical for both direct and indirect defenses to herbiv-ory. We provide genetic evidence that two 13-LOXs, ZmLOX10 and ZmLOX8, specialize in providing substratefor the green leaf volatile (GLV) and jasmonate (JA) biosynthesis pathways, respectively. Supporting the spe-cialization of these LOX isoforms, LOX8 and LOX10 are localized to two distinct cellular compartments, indi-cating that the JA and GLV biosynthesis pathways are physically separated in maize. Reduced expression ofJA biosynthesis genes and diminished levels of JA in lox10 mutants indicate that LOX10-derived signaling isrequired for LOX8-mediated JA. The possible role of GLVs in JA signaling is supported by their ability to par-tially restore wound-induced JA levels in lox10 mutants. The impaired ability of lox10 mutants to produceGLVs and JA led to dramatic reductions in herbivore-induced plant volatiles (HIPVs) and attractiveness toparasitoid wasps. Because LOX10 is under circadian rhythm regulation, this study provides a mechanistic linkto the diurnal regulation of GLVs and HIPVs. GLV-, JA- and HIPV-deficient lox10 mutants display compro-mised resistance to insect feeding, both under laboratory and field conditions, which is strong evidence thatLOX10-dependent metabolites confer immunity against insect attack. Hence, this comprehensive gene toagro-ecosystem study reveals the broad implications of a single LOX isoform in herbivore defense.
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Plants are important mediators between above- and belowground herbivores. Consequently, interactions between root and shoot defences can have far-reaching impacts on entire food webs. We recently reported that infestation of maize roots by the root feeding larvae of the beetle Diabrotica virgifera virgifera boosts shoot resistance against herbivores and pathogens. Root herbivory also induced DIMBOA levels and primed for enhanced induction of chlorogenic acid, two secondary metabolites that have been associated with biotic stress resistance. Interestingly, ABA emerged as a putative long-distance signal, possibly responsible for this effect. In this addendum, we investigate the role of root-derived ABA in the systemic regulation of aboveground DIMBOA, and the phenolic compounds chlorogenic acid, caffeic and ferulic acid. We discuss the relevance of the plant hormone in relation to defence against the leaf herbivore Spodoptera littoralis. Soil-drench treatment with ABA mimicked root herbivore-induced accumulation of DIMBOA in the leaves. Similarly, ABA mimicked aboveground priming of chlorogenic acid production, resulting in augmented accumulation of this compound upon subsequent shoot attack by S. littoralis. These findings confirm our notion that ABA acts as an important signal in the regulation of aboveground defence upon belowground herbivory. However, based on our previous finding that ABA alone is not sufficient to trigger aboveground resistance against S. littoralis caterpillars, the results suggest that the ABA-inducible effects on DIMBOA and chlorogenic acid are not solely responsible for root herbivore-induced resistance against S. littoralis. Full text HTML PDF
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The objective of this study was to verify the effectiveness of new patterns of sowing and to achieve a low-input organic system in two different environments (northern and southern Europe). The study was motivated by the hypothesis that more even sowing patterns (triangular and square) would significantly enhance the growth and yield of forage maize under widely varying conditions, compared with traditional mechanised rectangular seed patterns. An experiment was conducted in Madrid and duplicated in Copenhagen during 2010. A random block design was used with a 2 × 2 factorial arrangement based on two seed-sowing patterns: traditional (rectangular) and new (even) and two weed-management conditions (herbicide use and a low-input system). In both weed-management conditions and locations, the production of aerial maize biomass was greater for the new square seed patterns. In addition, the new pattern showed a greater effectiveness in the control of weeds, both at the initial crop stages (36 and 33% fewer weeds m-2 at the 4- and 8-leaf stages, respectively, in the Copenhagen field experiment) and at the final stage. The final weed biomass for the new pattern was 568 kg ha-1 lower for the Copenhagen experiment and 277 kg ha-1 lower in Madrid field experiments. In the light of these results, the new pattern could potentially reduce the use of herbicides. The results of the experiments support the hypothesis formulated at the beginning of this study that even-sowing patterns would be relatively favourable for the growth and yield of the maize crop. In the near future, new machinery could be used to achieve new seed patterns for the optimisation of biomass yield under low-input systems. This approach is effective because it promotes natural crop-weed competition.
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Most red wines commercialized in the market use the malolactic fermentationprocess in order to ensure stability from a microbiological point of view. In this secondfermentation, malic acid is converted into L-lactic acid under controlled setups. Howeverthis process is not free from possible collateral effects that on some occasions produceoff-flavors, wine quality loss and human health problems. In warm viticulture regions suchas the south of Spain, the risk of suffering a deviation during the malolactic fermentationprocess increases due to the high must pH. This contributes to produce wines with highvolatile acidity and biogenic amine values. This manuscript develops a new red winemakingmethodology that consists of combining the use of two non-Saccharomyces yeast strains asan alternative to the traditional malolactic fermentation. In this method, malic acid is totallyconsumed by Schizosaccharomyces pombe, thus achieving the microbiological stabilizationobjective, while Lachancea thermotolerans produces lactic acid in order not to reduce andeven increase the acidity of wines produced from low acidity musts. This technique reducesthe risks inherent to the malolactic fermentation process when performed in warm regions.The result is more fruity wines that contain less acetic acid and biogenic amines than thetraditional controls that have undergone the classical malolactic fermentation.
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