>Magister Scientiae - MSc / In agriculture crop productivity is greatly affected by stresses such as salinity, drought, temperature and honnonal changes of crop plants and responses to these stresses. Studies have shown that a natriuretic peptide based regulatory system responsible for water and ion homeostasis in animals has a hctcrologous equivalent in plants. Plant natriuretic peptide immunoreactants (irPNPs) have been reported to be involved in K+, Na+ and er ions fluxes in plants. Previously, an Arabidopsis thaliana transcript (AtPNP-A) encoding an irPNP (AtPNP-A) has been identified and isolated (Ludidi et al., 2002). The AtPNP-A a novel protein and part of its physiological role is presented here.

A cultura da cana-de-açúcar é submetida durante o seu desenvolvimento a diferentes condições ambientais, sendo o rendimento agrícola afetado diretamente por estas condições. Dessa variação ao longo do ciclo, surge a necessidade de se prever as respostas da cultura aos diferentes estímulos para fins de planejamento. Modelos de previsão de produtividade e qualidade da matéria-prima tornam-se ferramentas importantes na lavoura canavieira, objetivando suprir estimativas de rendimento ao longo da safra, visando à caracterização das alternativas de manejo, aumentando a eficácia das decisões gerenciais e estratégicas. O objetivo deste trabalho foi desenvolver modelos capazes de obter previsões de ATR - Açúcar Teórico Recuperável e TCH - toneladas de cana-de-açúcar por hectare, ao longo da safra, utilizando dados referentes aos fatores de produção como precipitação e temperatura. Os dados da Usina Açucareira Bortolo Carolo localizada no município de Pontal - SP das safras 1999/2000, 2000/2001 e 2001/2002 foram analisados em termos de produtividade (ATR e TCH), idade do canavial, solo, variedades e manejo, e com os dados testou-se modelos estatísticos de previsão de produtividade utilizando o programa computacional SAS "Statistical Analysis System". Os modelos de maturação (ATR) para cana de ano e cana de ano e meio foram os mais promissores obtendo um coeficiente de determinação R2 = 0,6943* e 0,7574*, respectivamente. Na simulação aplicou-se o teste qui-quadrado onde para cana de ano não há diferença estatística significativa entre os dados reais e calculados (&#945; < 0,05). Para cana de ano o meio, há diferença estatística significativa ao nível de 5%. Com isso, pode-se confirmar e quantificar a existência de influência da precipitação, graus-dias e graus-dias negativos na maturação e produtividade da cana-de-açúcar. O modelo de maturação para cana de ano mostrou-se mais confiável comparado ao modelo de maturação para cana de ano e meio, após a realização da simulação para a safra 2001/2002. A introdução do fator graus-dias negativos foi de suma importância, pois teve grande influência no modelo de maturação. Os modelos de produtividade não se mostraram confiáveis após a realização da simulação para a safra 2001/2002. / Sugarcane crop grows under different weather condition, what affects directly the crop productivity. From this variation during its cicle, in order to plan, the prediction of the crop response to different inducements is needed. Productivity predicting models and quality of row material become important tools in sugarcane crop, the goal of these models is to supply the productivity valuation during the harvest time, aiming the characterization of the management alternatives, increasing the efficiency of strategically and administration decision. The goal of the present work was to develop models able to predict RTA - Recoverable Theory Sugar and TSH - tons of sugarcane per hectare, during the harvest time, using data refered to production factors with precipitation and temperature. The data base of Bartolo Carolo Sugar-mill localized in Pontal - SP of the agricultural years 1999/2000, 2000/2001 and 2001/2002 was analyzed in productivity terms (RTA and TSH), cane plantation age, soil type, variety of sugarcane used and management with these data productivity predicting statistical models were tested through the use of the software SAS "Statistical Analysis System". The maturation models (RTA) to a twelve month and a eighteen month sugarcane were the most promising, because they got a significant determination coefficient R2 = 0,6943* e 0,7574*, respectively. In the simulation was applered the chi-square test, in that to twelve-month sugarcane there is no statistical significant difference between real and simulated data (&#945; < 0,05). To eighteen-month sugarcane there is statistical difference significant the 5% level. In conclusion, there is confirm and quantify the influence of precipitation, degrees-days and negative degrees-days in sugarcane maturation and productivity. The maturation model to twelve month sugarcane is more trustful them the eighteen month sugarcane, after the simulation with data of 2001/2002 agricultural year. The introduction of factor negative degrees-days was very important, because it had a great influence in the maturation model. The production models don’t show trustful after the simulation with data of 2001/2002.

A cultura da cana-de-açúcar é submetida durante o seu desenvolvimento a diferentes condições ambientais, sendo o rendimento agrícola afetado diretamente por estas condições. Dessa variação ao longo do ciclo, surge a necessidade de se prever as respostas da cultura aos diferentes estímulos para fins de planejamento. Modelos de previsão de produtividade e qualidade da matéria-prima tornam-se ferramentas importantes na lavoura canavieira, objetivando suprir estimativas de rendimento ao longo da safra, visando à caracterização das alternativas de manejo, aumentando a eficácia das decisões gerenciais e estratégicas. O objetivo deste trabalho foi desenvolver modelos capazes de obter previsões de ATR - Açúcar Teórico Recuperável e TCH - toneladas de cana-de-açúcar por hectare, ao longo da safra, utilizando dados referentes aos fatores de produção como precipitação e temperatura. Os dados da Usina Açucareira Bortolo Carolo localizada no município de Pontal – SP das safras 1999/2000, 2000/2001 e 2001/2002 foram analisados em termos de produtividade (ATR e TCH), idade do canavial, solo, variedades e manejo, e com os dados testou-se modelos estatísticos de previsão de produtividade utilizando o programa computacional SAS "Statistical Analysis System". Os modelos de maturação (ATR) para cana de ano e cana de ano e meio foram os mais promissores obtendo um coeficiente de determinação R2 = 0,6943* e 0,7574*, respectivamente. Na simulação aplicou-se o teste qui-quadrado onde para cana de ano não há diferença estatística significativa entre os dados reais e calculados (&#945; < 0,05). Para cana de ano o meio, há diferença estatística significativa ao nível de 5%. Com isso, pode-se confirmar e quantificar a existência de influência da precipitação, graus-dias e graus-dias negativos na maturação e produtividade da cana-de-açúcar. O modelo de maturação para cana de ano mostrou-se mais confiável comparado ao modelo de maturação para cana de ano e meio, após a realização da simulação para a safra 2001/2002. A introdução do fator graus-dias negativos foi de suma importância, pois teve grande influência no modelo de maturação. Os modelos de produtividade não se mostraram confiáveis após a realização da simulação para a safra 2001/2002. / Sugarcane crop grows under different weather condition, what affects directly the crop productivity. From this variation during its cicle, in order to plan, the prediction of the crop response to different inducements is needed. Productivity predicting models and quality of row material become important tools in sugarcane crop, the goal of these models is to supply the productivity valuation during the harvest time, aiming the characterization of the management alternatives, increasing the efficiency of strategically and administration decision. The goal of the present work was to develop models able to predict RTA - Recoverable Theory Sugar and TSH - tons of sugarcane per hectare, during the harvest time, using data refered to production factors with precipitation and temperature. The data base of Bartolo Carolo Sugar-mill localized in Pontal - SP of the agricultural years 1999/2000, 2000/2001 and 2001/2002 was analyzed in productivity terms (RTA and TSH), cane plantation age, soil type, variety of sugarcane used and management with these data productivity predicting statistical models were tested through the use of the software SAS "Statistical Analysis System". The maturation models (RTA) to a twelve month and a eighteen month sugarcane were the most promising, because they got a significant determination coefficient R2 = 0,6943* e 0,7574*, respectively. In the simulation was applered the chi-square test, in that to twelve-month sugarcane there is no statistical significant difference between real and simulated data (&#945; < 0,05). To eighteen-month sugarcane there is statistical difference significant the 5% level. In conclusion, there is confirm and quantify the influence of precipitation, degrees-days and negative degrees-days in sugarcane maturation and productivity. The maturation model to twelve month sugarcane is more trustful them the eighteen month sugarcane, after the simulation with data of 2001/2002 agricultural year. The introduction of factor negative degrees-days was very important, because it had a great influence in the maturation model. The production models don’t show trustful after the simulation with data of 2001/2002.

Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-03-06T16:50:54Z No. of bitstreams: 1 PGCS15MA142.pdf: 633444 bytes, checksum: 8a81ff9eef5fb3c2d963fd0ef75f5158 (MD5) / Made available in DSpace on 2018-03-06T16:50:54Z (GMT). No. of bitstreams: 1 PGCS15MA142.pdf: 633444 bytes, checksum: 8a81ff9eef5fb3c2d963fd0ef75f5158 (MD5) Previous issue date: 2015-09-21 / Capes / The research aimed to evaluate physical and chemical soil properties and performance of crops after 18 years of conducting of two soil management systems, between 2013 and 2015 in a Cambisol soil in Lages/SC. The treatments were formed by combining two tillage systems (conventional tillage and no-till) and three crops (corn, beans and soy). The experimental design was a randomized block with four replications in a factorial 2 x 3 split plot. The plots were the management systems and the subplots were the cultures, with dimensions respectively 6.5 x 36 and 6.5 x 12 m. The species were grown in the agricultural years of 2013/2014 and 2014/2015 and, at the end of each year, were evaluated grain yield (RG), the thousand grain weight (PMG) and production of dry biomass of shoot (MS). Soil samples were collected at the end of the second year in the 0-5, 5-10 and 10-20 cm for chemical analysis of organic carbon, pH, Al, H + Al, Ca, Mg, P and K and physical determinations of density, porosity, stability of aggregate and degree of clay flocculation. Data were subjected to analysis of variance and the means were compared by Tukey test (p < 0.05). Differences in crop performance occurred in the second year, finding in the no-till largest RG in soy and corn and higher PMG in bean, compared to conventional tillage. Beans and soy produce low MS, independent of the management system, while corn produces higher amount and higher in no-till. The type of plant species not influence the attributes of the soil, whereas the effect of management systems was evident. Bulk density was lower and aggregate stability and the degree of clay flocculation were higher in no-till at all layers. In conventional tillage, macroporosity was higher in the 0-5 cm layer, having an opposite behavior in depth. It was found in the no-till higher levels of P (0-5 cm layer), Ca and Mg (0-10 cm layer) and K and organic carbon (0-20 cm layer). Higher acidity was observed in no-till in the surface layer, with reducing the pH and elevated contents of Al and H + Al / Com a pesquisa objetivou-se avaliar atributos físicos e químicos do solo e o desempenho de culturas após 18 anos de condução de dois sistemas de manejo do solo, entre 2013 e 2015 em um Cambissolo Húmico em Lages/SC. Os tratamentos foram formados pela combinação de dois sistemas de manejo (preparo convencional e semeadura direta) e três culturas (milho, feijão e soja). O delineamento experimental foi o de blocos ao acaso com quatro repetições, em esquema fatorial 2 x 3 com parcelas subdivididas. As parcelas constituíram os sistemas de manejo e as subparcelas as culturas, as quais tinham dimensões de 6,5 x 36 m e 6,5 x 12 m, respectivamente. As espécies foram cultivadas nos anos agrícolas de 2013/2014 e 2014/2015 e, ao final de cada ano, foram avaliados o rendimento de grãos (RG), o peso de mil grãos (PMG) e a produção de massa seca de resíduos vegetais da parte aérea (MS). Amostras de solo foram coletadas ao final do segundo ano nas camadas de 0-5, 5-10 e 10-20 cm para determinações químicas de C orgânico, pH, Al, H + Al, Ca, Mg, P e K e determinações físicas de densidade, porosidade, estabilidade de agregados e argila dispersa em água. Os dados foram submetidos a análise de variância e as médias comparadas pelo teste de Tukey a 5% de significância. Diferenças no desempenho das culturas ocorreram no segundo ano, constatando-se na semeadura direta maior RG de soja e milho e maior PMG de feijão em comparação ao preparo convencional. Feijão e soja produziram baixa MS, independente do sistema de manejo, enquanto milho produziu maior quantidade e superior na semeadura direta. O tipo de espécie vegetal não influenciou os atributos do solo, enquanto que o efeito do sistema de manejo foi evidente. A densidade do solo foi menor e a estabilidade de agregados e o grau de floculação foram maiores na semeadura direta em todas as camadas. No preparo convencional a macroporosidade foi maior na camada de 0-5 cm, tendo comportamento inverso em profundidade. Constatou-se na semeadura direta maiores teores de P (camada de 0-5 cm), Ca e Mg (camada de 0-10 cm) e de K e C orgânico (camada de 0-20 cm). Maior acidez foi observada em semeadura direta na camada superficial, com redução do pH e elevação dos teores de Al e H + Al

This dissertation studies agricultural input intensification, defined as the increased use of modern inputs such as hybrid seeds, mineral fertilizer, herbicide, and pesticide in African agriculture. It also analyses the potential of this intensification to accelerate productivity growth and tests the effectiveness of two policies, input subsidies and land reforms, in promoting it and consequently in increasing crop yield. In the first essay, we argue that to create the conditions for the emergence of a green revolution in Africa, modern agricultural technologies have to be adopted as a package, not in a piecemeal fashion. This argument is consistent with a conceptual framework that we develop to illustrate the importance of harnessing strategic complementarities among agricultural technologies by adopting them simultaneously rather than sequentially. Based on this framework, we propose a methodology to estimate an index to measure agricultural input intensification in its many dimensions. The index provides a simple and intuitive measure to quantify joint adoption of several inputs and compare it across plots, crops, farmers, and regions. Applying this methodology to maize producers in Burkina Faso and Tanzania, we show that our estimated index is a valid measure of joint input adoption and effectively captures the relative importance of each input as well as the number of different inputs adopted. Using the estimated index, we find that simultaneous adoption of modern inputs in Burkina Faso and Tanzania is limited but not rare. Most importantly, we find that the impact of the adoption of individual modern input on yield is increasing with the level of intensification for others. In the subsequent two essays, we assess the effectiveness of government’s direct intervention through input subsidies and indirect intervention through land reforms in promoting agricultural input intensification and increasing productivity. Our empirical analyses focus on Burkina Faso, a country that has recently implemented a fertilizer subsidy program and is undertaking profound land reforms to improve land tenure security and land transferability among households. The second essay tests the hypothesis that subsidizing only one input might promote or discourage the use of other inputs. We find that fertilizer subsidy for maize farmers in Burkina Faso crowds in the use of hybrid seeds and crop protection chemicals, but discourages the use of manure. The last essay assesses whether the development of rural land rental markets can facilitate land transferability among farmers and increase input intensification and productivity. The findings suggest that land rental transfers land from less talented or committed farmers to the more able but have minimal impact on input intensification. However, our results show that land renters are more productive and better farm managers. These results suggest that the short-term gains from policies that foster the development of land rental markets in Burkina Faso, and more generally Africa, will likely be in term of efficiency rather than widespread adoption of modern agricultural technologies.

<p>  </p> <p>With the rapid growth in population and urbanization, an increased supply of fresh, nutritious, and safe food in urban areas is required. Relying solely on conventional agriculture for food production can be risky due to climate change and decreasing natural resources (i.e., water, and arable land). Vertical farming (VF) involves growing food crops (primarily leafy greens and small-statured fruits) at multiple levels in controlled environments with less land and water inputs. However, high operational costs have resulted in low-profit margins in VF, which are challenging the economic sustainability of the VF industry. With the present VF technology, it may be difficult to significantly reduce the operational costs. Therefore, maximizing the wholesale value of produce, which is determined by the total yield and sale price per unit quantity (or crop value), is critical for increasing profits in VF. In this research, the overall goal is to increase lettuce growth, nutritional quality, and food safety by optimizing the light quality of light-emitting diodes (LED) in VF to increase the whole value of produce and thus increase the VF profits. The objectives of the research were to (i) study the independent and interactive effects of monochromatic wavebands of light from UV-A (365 nm) to far-red (750 nm) on lettuce growth and nutritional quality; (ii) identify the effects of substituting moderate proportions of UV-A and a high proportion of UV-A coupled with far-red light in growth lighting on lettuce growth and nutritional quality; (iii) study the effects of lettuce cultivars and UV LED light on the survival of <em>E. coli</em> O157:H7 on lettuce in VF production.</p> <p>In the first study, we investigated the effects of different wavebands of light ranging from UV-A (370 nm) to far-red (733 nm), both independently and in combination with commercial growth lighting on lettuce growth, incident light-use efficiency (LUEinc), and levels of phytochemicals. Results showed that the monochromatic wavebands 389 and 733 nm had positive interactions with the growth lighting on lettuce. In addition, results also indicated that UV-A light at a peak wavelength of 389 nm could potentially increase phytochemical concentrations. In the second study, the effects of 40% UV-A (UV 389 nm) and 60% UV-A (UV 389 nm) plus 10% far-red (FR 733 nm) light for growth light during the plant stationary growth stage on lettuce biomass and biosynthesis of phytochemicals were examined. Results showed that substituting UV-A for 40% growth lighting during the plant stationary growth stage for seven days resulted in significantly increased levels of beta-carotene and phylloquinone in lettuce while slightly lowering lettuce growth. And the addition of far-red light to UV-A did not result in the expected increase in vegetative growth, while the levels of phytochemicals were not affected. In the third study, we first investigated the effects of four lettuce cultivars, including oakleaf, romaine, butterhead, and leaf lettuce on the survival of <em>E. coli</em> O157:H7 gfp+. Results showed that leaf lettuce had the lowest while oakleaf and romaine had the highest concentrations of <em>E. coli</em> O157:H7 gfp+ when sampled on days 2 and 7 after the inoculation, and on day 7 after harvest and storage at 4 °C. Then we examined the feasibility of supplementing UV-A, UV A+B, and UV A+C during plant growth stages to reduce <em>E. coli</em> O157:H7 gfp+ contamination on lettuce. Our results indicated that only the UV A+C light at an intensity of 54.4 μmol·m-2·s-1 for 15 minutes per day after inoculation reduced <em>E. coli</em> O157:H7 gfp+ contamination by 0.33 log CFU·g-1 without affecting plant growth and levels of phytochemicals.</p> <p>The outcomes from our research suggested that the interactive effects of monochromatic wavebands should be considered in developing light recipes. In addition, VF growers who are interested in improving the nutritional phytochemical levels such as beta-carotene and phylloquinone in lettuce while maintaining growth should consider adding a moderate proportion (< 40%) of near-blue UV-A (i.e., 389 nm) radiation during the plant stationary growth phase to growth lighting. However, shorter wavelengths of UV-A radiation are not recommended due to their negative effects on plant growth and high economic cost. For growers who are at high risk of <em>E. coli</em> O157:H7 contamination, it is suggested that growing leaf lettuce and supplementation of UV A+C LED light during the plant-growth period should be considered to reduce the <em>E. coli</em> O157:H7 contamination levels.</p>

To analyse the influence of crop rotations with a different ratio of nitrogen-fixing crops, catch crops and fertilisation with organic fertilisers on the following: 1. Soil enzyme activity; 2. Agrochemical properties of the soil and nitrogen balance; 3. Weed response; 4. Weed seed bank in the soil; 5. Crop yield and productivity. / Agroekosistemų optimizavimo augalų kaita, tarpiniais pasėliais ir organinėmis trąšomis ekologinėje žemdirbystėje tyrimai vykdyti 2004–2009 m., Lietuvos žemės ūkio universiteto Bandymų stotyje, sertifikuotame ekologinės žemdirbystės lauke, karbonatingame sekliai glėjiškame išplautžemyje (IDg8-k) – Calcari-Epihypogleyic Luvisol (LVg-p-w-cc). Tyrimų hipotezė. Optimizuoti agroekosistemas ekologinėje žemdirbystėje galima taikant priemonių kompleksą: parenkant sėjomainas su skirtinga azotą fiksuojančių augalų dalimi, auginant tarpinius pasėlius bei tręšiant organinėmis trąšomis. Tyrimų tikslas – įvertinti agroekosistemų optimizavimo galimybes ekologinėje žemdirbystėje derinant sėjomainas su skirtinga azotą fiksuojančių augalų dalimi, auginant tarpinius pasėlius ir tręšiant organinėmis trąšomis. Tyrimų uždaviniai: Ištirti sėjomainų su skirtinga azotą fiksuojančių augalų dalimi, tarpinių pasėlių ir tręšimo organinėmis trąšomis įtaką: 1. dirvožemio fermentų aktyvumui; 2. dirvožemio agrocheminėms savybėms ir azoto balansui; 3. pasėlių piktžolėtumui; 4. dirvožemio armens užteršimui piktžolių sėklomis; 5. augalų derlingumui ir bendrosios energijos kiekiui. Mokslinio darbo naujumas. Ekologinės žemdirbystės sąlygomis kompleksiškai įvertintas sėjomainų su skirtinga azotą fiksuojančių augalų dalimi, tarpinių pasėlių bei tręšimo organinėmis trąšomis poveikis agroekosistemoms. Tai suteikia naujų žinių apie potencialaus dirvožemio derlingumo palaikymo, pasėlių ir dirvos piktžolėtumo kontrolės... [toliau žr. visą tekstą]

This study aimed to evaluate commercial biofertiliser quality and awareness amongst smallholder farmers in Gauteng Province, South Africa. Sixty-seven smallholder farmers were interviewed in Gauteng Province by using a survey method, while the physicochemical and microbiological properties of 13 biofertilisers were evaluated using laboratory experiments. The results showed that awareness and use of biofertiliser are very poor, with 96% of the smallholder farmers surveyed not having biofertiliser knowledge. Furthermore, the products lack basic quality parameters: 54% contained no biofertiliser strain while all the products contained microbial contaminants. The pH, moisture content and viable microbial densities were below the acceptable standards for some of the products. Two fungal and 58 bacterial operational taxonomic units were obtained from the 16S rRNA Sanger sequences while 5 791 OTUs were obtained from the Illumina Miseq system. Approximately 40%, 41% and 59% of the isolates were positive for nitrogen-fixation, siderophore production and phosphorous solubilisation. Overall, there is a need to improve awareness amongst farmers and promote good-quality biofertiliser products for increased crop productivity. / Environmental Sciences / M. Sc. (Environmental Science)

Meeting the food demands of a growing population is one of the currently most critical issues for the world community. Additionally, negative impacts of climate change on agriculture are expected in some densely populated regions of developing economies. In this thesis, I examine spatial patterns of future impacts of population development and climate change on food security and how these impacts correlate with current patterns of food security and poverty. I aim to assess the global spatial patterns of food insecurity, concerning the current situation and future prognosis, to quantify the impact of population development and climate change on food security, and to examine to what extent poverty can explain spatial patterns. To identify spatial patterns, I performed a multiple correlation analysis. The aggregated impact estimate of population development and climate change was calculated by adding their respective national predictions. The explanatory power of poverty was evaluated using regression models which contained population development  predictions and current food security as functions of poverty rate. Based on the my results and a literature review I discuss the future geographic disparities of food security and the corresponding consequences for combating hunger. My results show that global geographic disparities are likely to increase substantially, mainly because population, and in turn food demand, will increase strongly in sub-Saharan Africa, the region with the highest decline of resources in relation to population. Impacts of climate change show a similar geographic pattern where foodinsecure regions will be affected the most. I found that poverty is a significant explanatory variable for both population growth and food security. The literature review support causality between variables, which places poverty at the core of food security issues. Poverty causes both a barrier to access food markets and population growth,which ultimately decrease food availability. In order to reach zero hunger for the coming generations, there is an urgent need to redistribute resources, change direction in agriculture practices and implement extensive political measures that carefully consider both local and global contexts.