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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Desempenho de cultivares de tomate (Lycopersicon esculentum Mill.) sob sistemas orgânicos em cultivo protegido. / Performance of tomato cultivars (Lycopersicon esculentum Mill.) organically-grown under greenhouse conditions.

Luciano Grassi Tamiso 25 May 2005 (has links)
A Agricultura Orgânica no Brasil cresce a taxas superiores a 30 % ao ano, devido, principalmente, a uma maior conscientização dos consumidores, que buscam hábitos alimentares mais saudáveis. Dentre as hortaliças, o tomate orgânico representa uma boa oportunidade de investimento para o produtor. No entanto, não existem recomendações técnicas ou genótipos desenvolvidos exclusivamente para esse sistema de produção, o que dificulta a expansão da área sob manejo orgânico. Diante disso, o presente trabalho teve como objetivo avaliar o desempenho de 11 cultivares de tomate (Avalon, Colibri, HTX – 5415, HTX – 8027, Sahel, San Marzano, San Vito, Júpiter, Raminho, Saladete DRW 3410 e Jane) sob dois sistemas orgânicos distintos em ambiente protegido, de março a outubro de 2004, nos municípios de Ibiúna, SP (experimento I) e Araraquara, SP (experimento II). Os experimentos foram conduzidos em propriedades que produzem tomate orgânico em escala comercial. No experimento I, as plantas foram conduzidas em linhas simples, com uma haste e com poda apical drástica, realizada acima do terceiro racemo. As estufas eram conjugadas, e a irrigação realizada por gotejo, utilizado também para a fertiirrigação com biofertilizantes. O espaçamento adotado foi de 1,5 m entre linhas e 0,35 m entre plantas. No experimento II, as estufas não eram conjugadas, e as plantas foram conduzidas em fileiras duplas, com duas hastes por planta, sem poda apical, no espaçamento de 0,8 m entre linhas e 0,6 m entre plantas. Em ambos os experimentos a densidade de plantio foi de 20 mil plantas por hectare. O delineamento experimental adotado foi em blocos ao acaso, com cinco repetições e dez tratamentos (Avalon, Colbri, HTX – 5415, HTX – 8027, Sahel, San Marzano, San Vito, Júpiter, Raminho e Saladete DRW 3410), para o experimento I, e quatro repetições e oito tratamentos (Avalon, Colbri, HTX – 5415, HTX – 8027, Sahel, San Marzano, San Vito, e Jane) para o experimento II. Considerando as condições em que os experimentos foram desenvolvidos, os resultados permitiram concluir que o híbrido Sahel mostrou o melhor desempenho para rendimento comercial, e para outros componentes da produção nos dois sistemas de condução ao qual foi submetido. No experimento I, destacaram-se, ainda, os híbridos Colibri e Saladete DRW 3410, que não diferiram estatisticamente de ‘Sahel’. Os híbridos, de um modo geral, mostraram melhor desempenho que os cultivares de polinização livre, porém, apenas “Sahel” mostrou maior amplitude adaptativa. No experimento I, conduzido com poda apical drástica, a porcentagem de frutos de melhor cotação comercial foi maior do que no experimento II, sem poda apical. O experimento I, também apresentou período de colheita menor e mais concentrado do que no experimento II. A traça-do-tomateiro revelou-se como fator limitante afetando significativamente o rendimento comercial. / Organic agriculture in Brazil has increased about 30% over the last few years since consumers are seeking for healthier foods, i.e. nutritious and free of pesticide residues. Among vegetable crops organically-grown, tomato constitutes an attractive economic opportunity for growers. However, the lack of information about management practices and cultivars adapted to organic production systems under protected cultivation are pointed out as important constraints that prevents this activity to expand. This work aimed to evaluate the performance of 11 indeterminate tomato cultivars (Avalon, Colibri, HTX – 5415, HTX – 8027, Sahel, San Marzano, San Vito, Júpiter, Raminho Sel. IPA, Saladete DRW 3410 and Jane) under two different organic management systems in unheated plastic greenhouse. Two experiments were carried out under climatically different areas of the State of São Paulo (experiment I, Ibiúna county, and experiment II in Araraquara county), from March to October 2004, in farms that commercially produce organic tomatoes under unheated plastic greenhouses. In both experiments tomato plants were staked. Tomato plants in experiment I were conducted with a single stem and apical bud removed upper 3rd cluster. The experiment was fertigated using with biofertilizers. Plant spacing was 1.5 m between rows and 0.35 m between plants. In experiment II, tomato plants were conducted with two stems without apical pruning. They were planted in double line and spaced 0.8 m between lines and 0.6 m between plants. In both experiments plant density was about 20,000 plants ha-1. Experiments were set up in a randomized complete block design. Experiment I had five replications and ten treatments, and experiment II four replications and eight treatments. Sahel hybrid exhibited an outstanding performance for marketable yield in both organic systems but, in experiment I did not differ statistically from hybrids Colibri and Saladete DRW 3410. Hybrid cultivars, in general, outperformed open pollinated cultivars for the evaluated parameters. Apical pruning had significant effect on the increase of tomato fruits graded as of better commercial acceptance (50-60 mm) and also was associated with concentration of the picking period. It was found that tomato pinworm (Tuta absoluta) constitutes a serious limiting pest for organically-grown tomatoes in both regions where the experiments were set up.
22

Composto bokashi com inóculo nativo e comercial, farinha de penas e a disponibilidade de nitrogênio e fósforo / Bokashi fermented compost with native and commercial inoculum, poultry feather manure and the nitrogen and phosphorus availability

Diego Fontebasso Pelizari Pinto 26 March 2018 (has links)
Poucos estudos existem sobre o efeito de diferentes inóculos microbianos na produção de composto fermentado bokashi e seu efeito no solo em relação à disponibilidade de nitrogênio e fósforo. A farinha de penas é outro potencial adubo orgânico que é pouco explorado no Brasil. O presente estudo teve por objetivo avaliar o efeito dos inóculos microbianos comercial e nativo, assim como da farinha de penas, na disponibilização de nitrogênio e fósforo, e sua interferência na nitrificação no solo. Os compostos bokashi foram feitos um com inóculo coletado em solo de área de preservação permanente misturado a solo de área de cultivo e outro com inóculo comercial. Os tratamentos: bokashi com inóculo comercial (BC), bokashi com inóculo nativo (BN), mistura de farelos com inóculo comercial (FC), mistura de farelos com inóculo nativo (FN), somente mistura de farelos (F), somente aplicação do inóculo comercial no solo (TC), farinha de penas (FP) e somente solo (T) foram misturados ao solo e incubados por 84 dias. Avaliações periódicas foram feitas dentro do período de incubação, as quais mensuraram a mineralização de nitrogênio, a nitrificação, a disponibilização de fósforo, a respiração basal, o carbono da biomassa microbiana, o coeficiente metabólico, o pH e o carbono e o nitrogênio total. O nitrogênio e o fósforo disponível foram avaliados nos compostos. O bokashi foi eficiente na disponibilização de fósforo no solo, assim como nitrogênio e fósforo no composto. A mineralização de nitrogênio foi reduzida quando os farelos passaram pelo processo de bokashi. A aplicação do bokashi não interferiu na nitrificação. O BC foi mais eficiente em disponibilizar fósforo e nitrogênio no composto e no solo que o BN. O FC apresentou uma atividade biológica de decomposição mais intensa, assim como maior mineralização de nitrogênio dos compostos quando comparado ao FN. O FN aumentou o nitrogênio orgânico no solo. Ambos inóculos demonstraram pouco efeito na nitrificação e na acidez do solo. A aplicação do FP no solo apresentou grande potencial para o suprimento de nitrogênio. / There is a reduced amount of studies on the different microbial inoculum effects in bokashi fermented compost and its effects related to soil nitrogen and phosphorus availability. The poultry feather manure is another potential fertilizer with little exploration in Brazil. The present study aim to evaluate the microbial inoculum effects, commercial and native, and the poultry feather manure, in soil nitrogen and phosphorus availability and nitrification interference. The bokashi composts were made one with collected inoculum in permanent preservation area mixed with crop soil and another with commercial inoculum. The treatments: commercial inoculum bokashi (BC), native inoculum bokashi (BN), commercial inoculum bran mixture (FC), native inoculum bran mixture (FN), bran mixture (F), just commercial inoculum in soil (TC), poultry feather manure (FP) and just soil (T) were mixed with a soil and incubated for 84 days. Periodic evaluations were made in incubation period, that one has assessed the nitrogen mineralization, the nitrification, the phosphorus availability, the basal respiration, the microbial biomass carbon, the metabolic coefficient, the pH and the total carbon and nitrogen. The nitrogen and phosphorus availability was evaluated in composts. The bokashi was efficient in soil phosphorus availability, like nitrogen and phosphorus in compost. The nitrogen mineralization was reduced with bokashi application. The bokashi application did not interfered in nitrification. The BC was more efficient in phosphorus and nitrogen availability in compost and in soil then the native inoculum bokashi. The FC show more biological decomposition activity, therefore with more nitrogen mineralization in relationship with FN. The FN increased the soil organic nitrogen. Both inoculum revealed little effect in nitrification and soil acidity. The FP application in soil demonstrated great potential in nitrogen supply.
23

Sustainable Agriculture Modernization, Orongo Village, Western Kenya

Andersson, Pär January 2010 (has links)
Today more than 200 million people are suffering from malnutrition in Africa, a major contributing factor to this is that Africa is the continent, by a large margin, that gets least yield per cultivated hectare. The relatively poor yield is not because Africa has no cultivable land but because of the prevailing agricultural practices. Orongo is a village in western Kenya, where large parts of agriculture are threatened by severe soil erosion problems and two-thirds of the inhabitants are totally dependent on agriculture for food and economic security. Today's agricultural practices have proved inadequate. Organic agriculture is not dependent on high-tech methods or expensive synthetic chemicals to provide a relatively good harvest and has therefore proved to have particularly good potential to increase the harvest of small-scale farmers living under poor circumstances. Organic agriculture relies entirely on natural processes that exist to increase soil fertility. The strengthening of these natural processes is the most important work in Organic agriculture with many long-lasting positive effects and a constant increase of soil fertility as a result. All the different components of organic agriculture have the potential to independently contribute to the desired development, decreased soil erosion and increased resistance of the local ecosystem are common consequences of organic agriculture components. There are many indications that Organic agriculture could provide a sustainable solution to the malnutrition problem in Orongo but to implement such modernization has globally proven difficult. The various components must all be adapted to the local biophysical circumstances, the local need and knowledge level of the farmers concerned. This document describes and analyzes these components from an Orongo perspective and looks at local cultural phenomena that must be considered. For a modernization to organic agriculture to be possible, a combined effort will be necessary, both to raise awareness of Organic agriculture through physical demonstration and classical learning but also provide economic security and incentives for farmers who want to change to Organic agriculture. It is also important to encourage entrepreneurship forces that can help to spread the different components of organic agriculture, components that on their own can contribute to a desired development.
24

Moving Towards Agroecosystem Sustainability: Safe Vegetable Production in Vietnam

Simmons, Luke Vincent 09 May 2008 (has links)
Humanity is facing a series of challenges, including climate change, biodiversity loss, decreasing availability of cheap fossil fuel energy and social inequality that, when taken together, constitute a sustainability crisis. Agricultural systems are vitally important for the survival of humanity and must be moved towards greater sustainability. In Vietnam, the challenges facing the agriculture sector are immediate and pressing. These challenges include the need to improve the livelihoods of millions of smallholder farmers, improve food safety and protect already heavily burdened ecosystems. In response to these challenges, a number of alternative agriculture approaches, including safe vegetable production and organic farming have emerged. While the use of chemical fertilizers and pesticides are not permitted in certified organic agriculture, the requirements for safe vegetable production are not nearly as stringent. Chemical fertilizers and some low toxicity pesticides are allowed in safe vegetable production as long as pesticide residues are below proscribed limits. This research assesses the contributions that safe vegetable production and organic agriculture are making to the development of more sustainable agroecosystems in Vietnam. Organic production is still in early stages of development, with the majority of the projects directed towards production for export. Safe vegetables in contrast are produced primarily for the domestic market and demand is driven by consumer concerns over excessive pesticide use in conventional vegetable production. A sustainability assessment that explores the effect that safe vegetable production is having on eight major criteria for sustainability is applied in Cu Chi District, Ho Chi Minh City. Research methods included semi-structured interviews and group discussions with safe vegetable farmers together with interviews of other key actors from the agricultural sector in Vietnam. Along with the goal of protecting human health, farmers are interested in safe vegetable production because of improved economic returns made possible by reduced inputs and greater market access. While safe vegetable production is contributing to greater agroecosystem sustainability, further improvements are needed in some areas, specifically in the use of agrochemicals. There are encouraging signs in relation to pesticides, with some farmers reducing their pesticide use and moving towards less-toxic pesticides. Further movement towards sustainability could be fostered by a shift to the use of pesticides only as a last resort, a further shift from chemical to organic fertilizers, and improved capacity of farmers to experiment with and adapt safe vegetable production techniques.
25

Moving Towards Agroecosystem Sustainability: Safe Vegetable Production in Vietnam

Simmons, Luke Vincent 09 May 2008 (has links)
Humanity is facing a series of challenges, including climate change, biodiversity loss, decreasing availability of cheap fossil fuel energy and social inequality that, when taken together, constitute a sustainability crisis. Agricultural systems are vitally important for the survival of humanity and must be moved towards greater sustainability. In Vietnam, the challenges facing the agriculture sector are immediate and pressing. These challenges include the need to improve the livelihoods of millions of smallholder farmers, improve food safety and protect already heavily burdened ecosystems. In response to these challenges, a number of alternative agriculture approaches, including safe vegetable production and organic farming have emerged. While the use of chemical fertilizers and pesticides are not permitted in certified organic agriculture, the requirements for safe vegetable production are not nearly as stringent. Chemical fertilizers and some low toxicity pesticides are allowed in safe vegetable production as long as pesticide residues are below proscribed limits. This research assesses the contributions that safe vegetable production and organic agriculture are making to the development of more sustainable agroecosystems in Vietnam. Organic production is still in early stages of development, with the majority of the projects directed towards production for export. Safe vegetables in contrast are produced primarily for the domestic market and demand is driven by consumer concerns over excessive pesticide use in conventional vegetable production. A sustainability assessment that explores the effect that safe vegetable production is having on eight major criteria for sustainability is applied in Cu Chi District, Ho Chi Minh City. Research methods included semi-structured interviews and group discussions with safe vegetable farmers together with interviews of other key actors from the agricultural sector in Vietnam. Along with the goal of protecting human health, farmers are interested in safe vegetable production because of improved economic returns made possible by reduced inputs and greater market access. While safe vegetable production is contributing to greater agroecosystem sustainability, further improvements are needed in some areas, specifically in the use of agrochemicals. There are encouraging signs in relation to pesticides, with some farmers reducing their pesticide use and moving towards less-toxic pesticides. Further movement towards sustainability could be fostered by a shift to the use of pesticides only as a last resort, a further shift from chemical to organic fertilizers, and improved capacity of farmers to experiment with and adapt safe vegetable production techniques.
26

Predicting Farmers¡¦ Behavioral Intention to Adopt Organic Agriculture

Wu, Ming-feng 04 July 2011 (has links)
Organic agriculture has offered a more sustainable alternative to conventional agricultural production and has grown rapidly in many countries. By 2012, over 5,000 hectares of land will be farmed organically in Taiwan. To understand and predict Taiwanese farmers¡¦ intention to become engaged in organic agricultural production, this study assessed participants¡¦ behavior determinants based on an integrated model, including Ajzen¡¦s (1988) theory of planned behavior and Roger¡¦s (1995) theory of innovation diffusion. An extra variable¡Xresponsibility¡Xwas also added to the model. The study interviews 166 farmers from organic farming class held by Agriculture Reform Fields, and 187 farmers from conventional farming class held by local Farmers¡¦ Associations. Assessments show that for farmers who attended organic-farming classes, (a) attitude, perceived behavioral control and responsibility predict participants¡¦ intention behind engagement in organic agriculture, and that (b) complexity, compatibility and observability predict their attitude. As for farmers who attended conventional-farming classes, assessments reveal that (a) attitude, subjective norm, perceived behavioral control and responsibility predict participants¡¦ intention behind engagement in organic agriculture, and that (b) environmental concern, complexity and observability predict participants¡¦ attitude. Furthermore, results also suggest that farmers who have younger ages, degrees of higher education, ownership of larger land, or suspicions that acquaintances fell ill due to pesticides are more willing to engage in organic agriculture. Implications regarding how to construct organic agriculture policy and how to distribute to farmers relevant information (e.g., certification process, sales skills and skills in organic farming) are discussed.
27

A discussion of organic agricultural and the verification system in Taiwan

Shiau, Ming-jong 23 August 2012 (has links)
Taiwan, as one of the Far East Asian countries, has been founded on agriculture since ancient times. Historically, farming has always played a pivotal role in the economic development of Taiwan. However, there have problems since the implementation of ¡§customary line of farming¡¨, which has been excessively adapted to the traditional farming method. For instance, the widespread use of pesticides and chemical fertilizer has not only severely damaged farmlands but has also threatened the quality of life for those involved in them. As well as the humanitarian issue of inorganic farming effecting workers within the industry, there is also a strong need to revise production from a growing change in demand in Taiwan¡¦s markets. It has been found that consumers are becoming more aware about issues regarding the quality, or lack of quality, in food available to them. This can be explained in relation to improvements in technology and increased living standards, where people are now able to be more selective about what they eat. This has lead to a general increase in the demand for organic produce in an attempt to achieve a healthier diet. From a growing awareness about where their food comes from, consumers are more cautious about buying from producers whose products fail to meet the required standards expected from organic produce. As well as a shift in demand within Taiwan¡¦s agricultural industry, the growing popularity of organic products in other counties has also affected Taiwan export markets. If the agricultural industry wishes to maintain the levels of prosperity it has enjoyed historically, it must yield to the growing demands of the market. But despite the growing appreciation for organic produce, there is a problem of how to verify authentically organic products from the inorganic. Whether or not organic products sold in the market are the genuine has been a growing dispute. It can be seen that more needs to be done encourage the verification system. This is if consumers peace of mind is to be properly addressed as to what can be safely regarded as genuinely organic. Also, further investigation into differences between organic and inorganic need to be continued if the implications to health are to be properly understood. With the increasingly recognized and trusted stamp of organic approval, advantages are available to both the consumer and producer. For consumers, it grantees quality of produce and assures consumers not to worry about and health and security issues. For producers, benefits from this system include an increase to their competitive advantages by way of offering higher quality produce. As a result, it can be argued to be beneficial to help farmers attain a verified stamp of approval for their produce.
28

Soil microbial communities and grain quality as affected by spring wheat (Triticum aestivum L.) cultivar and grain mixtures in organic and conventional management systems

Nelson, Alison Gail Unknown Date
No description available.
29

Investigation of the blade roller for organic green manure management

Vaisman, Iris 22 September 2010 (has links)
The objective of this study was to investigate the effects of using the blade roller for no-till/reduced tillage in organic green manure management. The study was conducted in Carman, Manitoba and Oxbow, Saskatchewan. In the spring, a pea/oat intercrop was seeded as a green manure. The green manure was terminated by rolling, tilling, or a combination of the two. The following spring, spring wheat was seeded. In the year of the green manure, measurements taken included: biomass, soil nitrogen, and ammonia emissions. In the year of the wheat, measurements taken included: soil cover, soil moisture, weed competition, soil nitrate-N, and wheat biomass. Results showed increased soil cover, minimal effect on soil moisture, delayed wheat development, an effect on weed communities, reduced rate of nitrogen release, and reduced wheat yield. No-till green manure management can therefore provide benefits of soil conservation and nitrogen conservation but may result in decreased wheat yield.
30

Investigation of the blade roller for organic green manure management

Vaisman, Iris 22 September 2010 (has links)
The objective of this study was to investigate the effects of using the blade roller for no-till/reduced tillage in organic green manure management. The study was conducted in Carman, Manitoba and Oxbow, Saskatchewan. In the spring, a pea/oat intercrop was seeded as a green manure. The green manure was terminated by rolling, tilling, or a combination of the two. The following spring, spring wheat was seeded. In the year of the green manure, measurements taken included: biomass, soil nitrogen, and ammonia emissions. In the year of the wheat, measurements taken included: soil cover, soil moisture, weed competition, soil nitrate-N, and wheat biomass. Results showed increased soil cover, minimal effect on soil moisture, delayed wheat development, an effect on weed communities, reduced rate of nitrogen release, and reduced wheat yield. No-till green manure management can therefore provide benefits of soil conservation and nitrogen conservation but may result in decreased wheat yield.

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