MSCAGR (Plant Production) / Department of Plant Production / Soil infertility, water scarcity, and availability of high yielding and drought tolerant crop genotypes remain major constraints for agricultural production in semi-arid regions. These constraints are major threats to sustainable crop production and food security. Management practices in such areas should always be geared towards improving productivity at a low cost while sustaining soil fertility. Preliminary studies showed the huge potential of chickpea in the dry environments of the North Eastern South Africa. However, lack of nodulation in chickpea has been reported in these regions probably due to low soil pH, insufficient rhizobial populations or total lack of infective native rhizobia. Therefore this study assessed the effect of biochar and rhizobium inoculation on soil pH, nodulation, growth, yield and chlorophyll content of chickpea in Mpumalanga (Nelspruit) and Limpopo (Thohoyandou) Provinces, South Africa. Two field experiments were planted during winter 2015 and 2016. Treatments consisted of three levels of biochar (0, 10 and 20 t ha-1), two Rhizobium inoculation levels (with and without Rhizobium inoculation) and three chickpea genotypes (ACC #4, ACC #5, and ACC #6) in a factorial combination arranged in randomized complete block design replicated three times. Crop phenology (days to 50% emergence, flowering, podding, and physiological maturity), crop growth (plant height, canopy cover, number of primary and secondary branches), nodulation (number of nodules per plant and nodule dry weight), yield and yield components (number of pods per plant, number of seeds per pod and 100 seed weight [100-SW]), and chlorophyll content were determined at various crop growth stages. Identification and isolation of native rhizobia from soils was done using standard protocols. Data obtained were subjected to analyses of variance using the general linear model of Genstat software version 17. Significant differences between the treatments means were compared using the standard error of difference (SED) of the means at 5% level. Correlation analyses were performed to assess the relationship between parameters. Molecular data was subjected to BLASTn in National Centre for Biotechnology Information (NCBI) searches for identification of isolated strains Application of biochar at 10 and 20 t ha-1 increased soil pH by 0.7 pH units in Thohoyandou (clay soil) in 2015 and 2016, respectively. Soil pH increased by 0.77 pH units at 10 t ha-1 and 1.2 pH units at 20 t ha-1 in Nelspruit (loamy sand) in 2015 and 2016, respectively. Similarly, rhizobium inoculation increased soil pH by 0.2 (Thohoyandou) and 0.5 (Nelspruit) pH units in 2015 and 2016, respectively. There was a 100% increase in nodulation in inoculated compared to uninoculated treatments. There was no effect of biochar and rhizobium inoculation on number of days to 50% flowering, podding, v physiological maturity and on plant height. However, plant height varied with genotypes. Biochar application increased above ground biomass by 17% (10 t ha-1) and 12% (20 t ha-1), and 100 seed weight by 9% (10 t ha-1) and 7% (20 t ha-1) in Thohoyandou in 2015. Rhizobium inoculation increased yield and yield components in Thohoyandou in both seasons; biomass was greater by (31 and 23%), grain yield (26 and 24%), number of pods per plant (18 and 31%), and 100-SW (10 and 13%) in 2015 and 2016, respectively. Similarly, rhizobium inoculation increased biomass (53.4%), grain yield (81%), number of pods per plant (54%) and number of seeds per pod (89%) in Nelspruit in 2015. Genotype did not affect yield and yield components in Nelspruit. In contrast, genotype affected above ground biomass, grain yield, harvest index, number of pods per plant, and number of seeds per pod in 2015 in Thohoyandou with ACC #6 producing greater yield compared to ACC #4 and 5. The analysis for native rhizobia showed that agricultural fields in Nelspruit and Thohoyandou lack effective strains of rhizobium. The identified strains according to 16s gene region were Klebsiella variicola, Burkholderia cenocepacia, Bacillus subtilis and Ochrobactrum spp. The effects of biochar and rhizobium inoculation were more pronounced in Thohoyandou compared to Nelspruit. Therefore biochar and rhizobium inoculation may improve chickpea productivity in Limpopo and Mpumalanga Provinces through improved soil pH, nodulation, growth, yield and yield components. / NRF

Les infections multiples sont courantes dans la nature et sont considérées comme très importantes dans l'évolution des caractéristiques biologiques des parasites. Théoriquement, les infections multiples devraient entraîner une évolution de la virulence à la fois comme stratégie adaptative et comme stratégie plastique. Dans cette thèse, j'utilise Hyaloperonospora arabidopsidis, un parasite naturel d'Arabidopsis thaliana, qui s'est avéré pratique pour des études en écologie évolutive, pour étudier: i) les infections multiples consécutives à la co-inoculation et à l'inoculation séquentielle; succès de l'infection et succès de transmission d’une souche individuelle (génotypage par PCR) et des phénotypes d'infection, y compris virulence entre inoculation unique et mixte, iii) effet du délai d'inoculation et d'ordre des souches inoculées sur les phénotypes d'infection et le succès de l'infection individuelle. Ici, j'ai trouvé une fréquence plus élevée de co-infection à la suite de l'inoculation séquentielle que à la suite de la co-inoculation des mêmes combinaisons de souches. L'inoculation mixte de certaines combinaisons de souches a entraîné une modification des phénotypes d'infection, souvent avec un succès d'infection plus faible chez certaines souches à la suite des inoculations en mélanges qu’en inoculation simple. Ce résultat implique une interférence entre les souches dans l'inoculum mixte. La virulence globale de l'infection après l'inoculation mixte n'était pas toujours supérieure à celle de l'infection à souche simple. De plus, les souches uniques utilisées dans ces expériences ne différaient pas toujours les unes des autres en termes de virulence. Le seul test d'un mélange de génotypes à trois souches a provoqué une virulence globale plus élevée que les trois infections à souche unique respectives. Une plus grande virulence globale dans ce cas pourrait être due à la plasticité des souches parasitaires inoculées, à la réponse à la présence d'autres souches dans l'inoculum mixte ou à l'effet de multiples souches supprimant le système de défense de l'hôte. Lorsque les souches ont été inoculées de manière séquentielle et non ensemble, le succès de l'infection de souches individuelles différait entre les différents ordres d'inoculation, ce qui pourrait être dû à des effets indirects via le système de défense de l'hôte. En résumé, l'inoculation séquentielle a semblé réduire l'interférence entre les souches parasitaires, avec un effet de décalage temporel et d'ordre de la souche inoculée sur le succès de l'infection de souches individuelles. Une interférence dans un inoculum mixte peut générer différents succès d'infection et phénotypes d'infection à partir des inoculations individuelles respectives. J'ai trouvé un cas évident de virulence globale plus élevée dans les infections causées par des inoculations mixtes. Par conséquent, une virulence globale plus élevée peut se produire malgré le fait que nous ne trouvions pas de meilleures performances de génotypes plus virulents dans des infections à la suite d'inoculations mixtes. Ainsi, ces résultats ne permettent pas de prédire l’évolution de la virulence supérieure parmi ces combinaisons de souches testées. Cependant, la plasticité des phénotypes des souches inoculées dans l'inoculum mixte a généré une virulence globale de l'infection plus élevée. Ces résultats peuvent aider à comprendre comment les génotypes de parasites répondent aux infections mixtes. / Multiple infections are common in nature, and are considered very important in the evolution of parasite life-history traits. Theoretically, multiple infections should lead to evolution of higher levels of virulence both as an adaptive and as a plastic strategy. In this thesis I use Hyaloperonospora arabidopsidis, a natural parasite of Arabidopsis thaliana, which has proven a useful tool for unlocking some evolutionary ecology questions, to investigate: i) multiple infections following co-inoculation and sequential inoculation, ii) number of infected plants, infection success and transmission success of individual strain (genotyping via PCR), and infection phenotypes including virulence between after single- and mixed inoculation, iii) effect of time lag of inoculation and order of inoculated strain on infection phenotypes and individual strain infection success. Here I found that sequential inoculation contributed higher frequency of co-infection than co-inoculation of the same strain combinations. Mixed inoculum of some strain combinations led to modification of overall infection phenotypes, often with poorer infection success of individual strains compared with that of the more infectious strains. This result implies interference between strains in mixed inoculum. Overall virulence of infection after mixed inoculation was not always higher than that of single strain infection. Furthermore the single strains used in these experiments did not always differ from each other in virulence. The one test of a three-strain mixture of genotypes caused higher overall virulence than the three respective single strain infections. Higher overall virulence in this case might be caused by plasticity of inoculated parasite strains reponse to the presence of other strains in mixed inoculum or an effect of multiple strains suppressing the host defence system. When strains were inoculated sequentially instead of together, infection success of individual strains differed between different orders of inoculation, which could be due to indirect effects via the host defence system. In summary, sequential inoculation seemed to reduce interference between parasite strains, with effect of time lag and order of inoculated strain on infection success of individual strains. Interference in mixed inoculum can generate different infection successs and infection phenotypes from the respective single inoculations. I found one clear case of higher overall virulence in infections caused by mixed inoculations. Thus higher overall virulence can occur despite our not finding higher performance of more virulent genotypes from infections following mixed inoculations. Thus these finding do not predict the evolution of higher virulence among these strain combinations tested. However, plasticity of phenotypes of inoculated strains in mixed inoculum did generate higher overall virulence of infection. These findings can help to understand how the parasite genotypes respond to in mixed infections.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Biofertilisers are rhizosphere microorganisms inoculated to reduce the need for N or P fertiliser application and maximise plant growth and nutrition, resulting in greater grain yield and N or P content. This study aimed to evaluate the effectiveness of diazotrophic bacteria isolated from the rhizosphere of wheat in Victoria, Australia. This thesis shows that N2-fixing Burkholderia species have great potential as biofertilisers on wheat productivity. In Chapter 2, strains of bacteria were isolated from wheat-growing soils in main Victoria wheat belt at Horsham and Birchip in North West Victoria. Strains were identified as Burkholderia spp. by their closest matches in the 16S DNA and by morphology and physiology. In Chapter 3, one selected strain from each of Birchip and Horsham were used to inoculate wheat in a pot trial in a glasshouse during winter-spring. Soil was collected on site from wheat fields. Pots were inoculated with these strains to evaluate the effects of Burkholderia inoculum as biofertiliser on the plant growth and yield. Different nitrogen sources (urea 46% N and ammonium sulphate 21% N) were used as fertiliser at one of four levels (0, 50, 100 and 150 kg N/ ha). There was a greater effect in Birchip than in Horsham soil and with ammonium sulphate than with urea due to waterlogying in Horsham soil. In Chapter 4, field-grown wheat was inoculated with the same strains of Burkholderia. Three experiments were carried out in plots at two sites, dryland and irrigated fields at Horsham and a dryland field at Birchip, during the winter wheat season of 2006, to evaluate the effect of Burkholderia species inoculum and different types of nitrogen source at one of four levels of added N (0, 50, 100 and 150 kg N/ha) on wheat growth and yield. The effects of both bacterial inoculation and N fertiliser on growth promotion and grain yield. Since 2006 was a year of drought, dry land crops were unsuccessful. Grain %N as well as total N content in grain per area in the Horsham irrigated field increased with increasing N fertiliser levels up to 100 kg N/ha. In Chapter 5, acetylene reduction (ARA) activity was measured in the pots for both inoculated and uninoculated plants at various growth stages and populations of nitrogen-fixing bacteria associated with the wheat roots and bulk soil were measured in addition to biomass and N content of plants and grain. Molecular tracing using specific primers showed that the inoculum was present only in inoculated treatments. Up to 60% of the increased N content of the grain in inoculated plants was potentially derived from nitrogen fixed by the inoculum in the rhizosphere. It was concluded that the most significant result due to inoculation was the consistent maximal increase of N content in grain in inoculated treatments with ammonium sulphate fertiliser at 100 kg N/ha. Inoculation with Burkholderia consistently increased %N in wheat grain, with the potential benefit of decreasing the production cost and reducing use of chemical fertilisers.

Graduation date: 1999

Thesis (Ph. D.)--University of Wisconsin--Madison, 1959. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 136-146).

Made available in DSpace on 2016-05-17T16:51:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-02-13. Added 1 bitstream(s) on 2016-05-17T16:54:36Z : No. of bitstreams: 1 000864065.pdf: 975614 bytes, checksum: 877180cdde2c8402ed80b28e5bd0fd23 (MD5) / A soja (Glycine max (L.) Merril) é uma das mais importantes culturas na economia mundial. No Brasil, a inoculação de sementes de soja com bactérias fixadoras de nitrogênio atmosférico é essencial, e dispensa a necessidade de adubação complementar com nitrogênio, gerando uma economia de aproximadamente 3 milhões de dólares para o país. O uso de Azospirillum brasilense tem sido utilizado em conjunto com o Bradyrhizobium a fim de otimizar a nodulação e gerar respostas positivas em produtividade e qualidade de grãos. Dessa forma, o trabalho teve como objetivo avaliar os efeitos de doses de Bradyrhizobium japonicum e Azospirillum brasilense no desenvolvimento das plantas, produção e qualidade fisiológica de sementes de soja. O trabalho foi desenvolvido em área experimental da UNESP - Ilha Solteira, localizada no município de Selvíria (MS), com delineamento experimental de blocos casualizados dispostos em um esquema fatorial 3x4, com quatro repetições, em dois cultivares de soja (TMG 1179RR e TMG 4182). Os tratamentos foram constituídos por: Bradyrhizobium japonicum (testemunha sem inoculação, 100 ml ha -1 e 200 ml ml ha -1 ) e Azospirillum brasilense (testemunha sem inoculação, 100 ml ha -1, 200 ml ha -1 e 400 ml ha -1 ). A semeadura foi realizada em dezembro de 2013, manualmente. Foram analisados: os teores nutricionais foliares, sistema radicular, componentes de produção, produtividade e qualidade fisiológica de sementes de soja obtidas. Concluiu-se que: O Azospirillum brasilense aumentou o teor foliar de cálcio e o teor de nitrogênio e proteína bruta das sementes da soja TMG 1179RR; a inoculação da soja com Azospirillum brasilense isolada ou em co-inoculação influencia significativamente o desempenho morfofisiológico das raízes e proporciona maior nodulação pelas plantas da soja; o uso de Azospirillum brasilense em co-inoculação com Bradyrhizobium japonicum... / Soybean (Glycine max (L.) Merrill) is one of the most important crops in the world economy. In Brazil, soybean inoculation with fixing bacteria atmospheric nitrogen is essential, and eliminates the need to additional fertilizers with nitrogen, generating savings of approximately $ 3 million for the country. Use of Azospirillum brasilense has been used in conjunction with Bradyrhizobium to optimize nodulation and generate positive responses in productivity and quality beans. Thus, the study aimed to evaluate the effects of doses of Bradyrhizobium japonicum and Azospirillum brasilense in plant development, production and physiological quality of soybean seeds. The study was conducted at UNESP experimental area - Ilha Solteira, located in Selvíria (MS), with experimental design of arranged randomized blocks in a 3x4 factorial design with four replications, in two soybean cultivars (TMG 1179RR and TMG 4182). The treatments were: Bradyrhizobium japonicum (without inoculation, 100 mL ha -1 and 200 mL ha -1 ) and Azospirillum brasilense (without inoculation, 100 mL ha -1, 200 mL ha -1 and 400 mL ha -1 ). Seeds were sown in December 2013, manually. They were analyzed: foliar nutritional content, root system, yield components, productivity and physiological quality of soybean seeds obtained. In conclusion: The Azospirillum brasilense increased the foliar content of calcium and nitrogen content and crude protein seed soy TMG 1179RR; inoculation of soybean isolated Azospirillum brasilense or co-inoculation significantly influences the performance of morphophysiological roots and provides increased nodulation by soybean plants; Azospirillum brasilense the use of co-inoculation with Bradyrhizobium japonicum at a dose of 200 mL ha -1 of each inoculant gave increase of 2,403.9 kg ha -1 in the yield of soybean cv. TMG 1179RR compared to the control (without inoculation of both); and that inoculation did not ...

Made available in DSpace on 2015-09-17T15:25:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-02-26. Added 1 bitstream(s) on 2015-09-17T15:48:50Z : No. of bitstreams: 1 000846527.pdf: 2770788 bytes, checksum: 8ebfb94d9b98fde473b31e8ad2e518da (MD5) / O crescimento das áreas cultivadas sob Sistema Plantio Direto (SPD) no Brasil, está cada vez mais diversificando as formas como os sistemas de produção são implantados e manejados. Os elevados gastos com insumos agrícolas fazem com que a produção tenha altos custos. Assim, cresce o interesse pelo uso de inoculantes que em sua composição possuam bactérias promotoras de crescimento de plantas, principalmente pela busca de uma agricultura sustentável com menor poluição ambiental aliado a redução dos custos de produção. Diante disso, o presente estudo objetivou verificar em um Latossolo Vermelho Distrófico, sob condições irrigadas no Cerrado: 1) o efeito da adubação fosfatada e da inoculação ou não com Azospirillum brasilense nas sementes de aveia preta sobre sua nutrição e produtividade de matéria seca da parte aérea e raízes; 2) avaliar o efeito residual da adubação fosfatada e da decomposição da palhada da aveia sobre o crescimento e produtividade do milho com e sem inoculação com Azospirillum brasilense e do capim-Marandu em consórcio; 3) após o período simulando a vedação do pasto (60 dias após a colheita do milho), avaliar a qualidade bromatológica e nutricional do capim-Marandu, e o efeito de sua palhada sobre os componentes da produção e produtividade do feijão de inverno em sucessão; e 4) ao final de cada ciclo produtivo avaliar o efeito dos tratamentos sobre a fertilidade do solo. O delineamento experimental utilizado foi o de blocos casualizados, com 4 repetições, em esquema fatorial 5 x 2, ou seja, cinco doses de P 2 O 5 (0; 30; 60; 120 e 240 kg ha -1 ) aplicadas a lanço na semeadura da aveia preta cultivar IAPAR 61, com e sem a inoculação das sementes com a bactéria diazotrófica Azospirillum brasilense, na dose de 100 mL 25 kg -1 de sementes. Cada unidade experimental (parcela) constituiu-se de 4,4 m de largura e 10 m de comprimento, perfazendo 44 m 2 . A inoculação das sementes de... / The growth of cultivated areas under no-tillage system in Brazil, is increasingly diversifying the ways in which production systems are deployed and managed. The high expenditure on agricultural inputs cause the production has high costs. Thus, the growing interest in the use of inoculants that in its composition have bacteria that promote plant growth, especially the search for sustainable agriculture with less environmental pollution combined with lower production costs. There fore, this study aimed to verify in a Oxisoil under irrigated conditions in the Cerrado: 1) the effect of phosphorus fertilization and inoculation with and without Azospirillum brasilense in oat seeds on their nutrition and dry matter shoots and roots yield; 2) to evaluate the residual effect of phosphate and decomposition of oat straw on growth and yield of corn with and without inoculation with A. brasilense and Marandu grass in the consortium; 3) after the period simulating the fence pasture (60 days after the corn harvest), assess the chemical and nutritional quality of Marandu grass, and the effect of their trash on the production components and winter bean productivity in succession ; and 4) the end of each crop cycle to evaluate the effect of treatments on soil fertility. The experimental design was a randomized block design with four replications in a factorial scheme 5 x 2, with five doses of P 2 O 5 (0, 30, 60, 120 and 240 kg ha - 1 ) broadcast applied at sowing oats IAPAR 61 cultivar, with and without seed inoculation with bacteria diazotrophic A. brasilense at a dose of 100 mL 25 kg -1 of seed. Each experimental unit (plot) consisted of 4.4 m wide and 10 m long, totaling 44 m 2 . Seeds inoculation oat by A. brasilense increased plant height, more dry matter of shoots and roots production. Also provided an increase of N and P in shoots, and N and Mg in root tissue culture. The phosphorus fertilization in oat increased the dry matter of shoots and roots ...

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The United States has established breastfeeding as an important health indicator within the Healthy People agenda. Healthy People target goals for breastfeeding initiation, duration, and exclusivity remain unmet. The US Surgeon General's Office reports that lack of knowledge and widespread misinformation about breastfeeding are barriers to meeting Healthy People goals. Breastfeeding mothers are vulnerable to messages that cast doubt on their ability to breastfeed. Very little research has examined specific approaches to help people resist negative messages about health beliefs and behaviors. The objective of this quasi-experimental study was to test an intervention designed to help mothers defend their breastfeeding decisions and resist influences that attempted to persuade them to give formula to their babies. Women attending prenatal breastfeeding classes were recruited and assigned to comparison and intervention groups. The intervention was a board game based on McGuire's inoculation theory of resistance to influence. Controlling for intention to breastfed, intervention and comparison groups were examined for differences in maternal self-efficacy to resist persuasion to give formula and breastfeeding rates for initiation, duration, and exclusivity. Data analyses consisted of analysis of covariance and logistic regression. There was no significant difference between comparison and intervention groups, both groups had high self-efficacy to resist giving formula to their babies; nor were there significant differences regarding breastfeeding initiation, duration and exclusivity. The lack of significant differences may have been influenced by ceiling effects in all of the breastfeeding variables, possibly due to the high socioeconomic level of the sample. The intervention may have worked better in women who were more prone to dissuasive influence, such as those with lower education.