732 resultados para Bitter-rot


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Sodium is an essential nutrient with important functions in the organism, however, its ingestion in excess may cause various health problems such as arterial hypertension, brain diseases, heart failure and chronic renal failure. In this context, the present study proposes to prepare Minas Padrão cheese with different contents of sodium with the objective of evaluating the effect of the addition of potassium chloride in sensory characteristics and hysicochemical properties, as well as in the proximal composition and in microbiological quality. The cheeses were elaborate in concentrations of 100% of NaCl (C), 80% of NaCl + 20% of KCl (T1), 60% of NaCl + 40% of KCl (T2), 40% of NaCl + 60% of KCl (T3) and 20% of NaCl + 80% of KCl (T4) and stored for 20 days at 10 ºC. The proximal composition and physicochemical was based on the determination of moisture content, fat, protein, ash, chloride, sodium, potassium, titratable acidity and pH of all treatments after 20 days of storage. The microbiological quality of the samples was monitored through the count of Total Coliforms and Escherichia coli, Staphylococcus aureus, Salmonella spp., mold and yeast in the first and fifteenth day of storage. The sensorial characterization was performed by the technique of Free Profile choice. The results showed that the replacement of sodium chloride by potassium in the Minas Padrão cheese in concentration higher than 40% presented significantly higher moisture contents. Cheese with a reduction greater than 60% of sodium obtained significantly effect in the titratable acidity, presenting higher values compared to the other treatments. The cheese with 20% of salt replacement did not differ statistically in relation to the control. When the proportion of substituent was increased, a significant reduction of the sodium content of up to 73% was observed. As the sodium was replaced by potassium in cheese, the potassium content increased significantly, stablishing a reduction of 82% in relation to the control. There was no effect to sodium substitution by potassium in fat, protein, ash and chlorides, as well as the pH values. The microbiological results were in accordance with the current legislation, therefore suitable to be eaten. According to the Free Profile Choice technique it was observed that the control C cheese (100% of NaCl) showed results very close to the other treatments, differing only in flavor attributes. The replacement of sodium by potassium in proportions of 20% contributed to a bitter taste detected by the tasters. Whereas, the appearance, flavor and texture attributes showed no significant differences compared to the Minas Padrão cheese.

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Fiji exports approximately 800 t year-1 of 'Solo Sunrise' papaya marketed as 'Fiji Red' to international markets which include New Zealand, Australia and Japan. The wet weather conditions from November to April each year result in a significant increase in fungal diseases present in Fiji papaya orchards. The two major pathogens that are causing significant post-harvest losses are: stem end rot (Phytophthora palmivora) and anthracnose (Colletotrichum spp.). The high incidence of post-harvest rots has led to increased rejection rates all along the supply chain, causing a reduction in income to farmers, exporters, importers and retailers of Fiji papaya. It has also undermined the superior quality reputation on the market. In response to this issue, the Fiji Papaya industry led by Nature's Way Cooperative, embarked on series of trials supported by the Australian Centre for International Agricultural Research (ACIAR) to determine the most effective and economical post-harvest control in Fiji papaya. Of all the treatments that were examined, a hot water dip treatment was selected by the industry as the most appropriate technology given the level of control that it provide, the cost effectiveness of the treatment and the fact that it was non-chemical. A commercial hot water unit that fits with the existing quarantine treatment and packing facilities has been designed and a cost benefit analysis for the investment carried out. This paper explores the research findings as well as the industry process that has led to the commercial uptake of this important technology.

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Similar to other developing countries Brazil’s position on climate change emphasises national sovereignty and the principle of “common but differentiated responsibilities”. However, in recent years Brasilia has also announced voluntary reductions in carbon emissions, making Brazil one of the leading emerging countries in its approach to climate change, while enhancing its international reputation and legitimacy. Compared to its neighbours Brazil has older and more developed domestic environmental institutions and movements. Yet, Brazil’s global leadership on climate change does not translate into a similar role in regional environmental governance. In the 2000s Argentina and Uruguay became embroiled in a bitter environmental conflict involving a shared natural resource, the Uruguay River. Brazil not only refused to mediate, but also kept it out of regional forums insisting on the conflict’s bilateral nature. Furthermore, Mercosur’s environmental agenda has progressively become eroded while Brazilian-led Unasur lacks an institutional framework dedicated to environmental concerns. This indicates that environmental concerns are far more important for Brazil’s global image than for its role as a regional leader. It also highlights the limited scope of the climate change negotiations which focus narrowly on reducing carbon emissions, without taking wider concerns over energy generation or environmental and social justice into account. Brazil has promoted hydropower generation, portrayed as “clean” energy. Yet, these projects have sparked strong domestic and regional civil society opposition due to their social and environmental costs which make it difficult for Brazil to claim a regional leadership role on environmental concerns.

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Soilborne diseases such as Fusarium wilt, Black root rot and Verticillium wilt have significant impact on cotton production. Fungi are an important component of soil biota with capacity to affect pathogen inoculum levels and their disease causing potential. Very little is known about the soil fungal community structure and management effects in Australian cotton soils. We analysed surface soils from ongoing field experiments monitoring cotton performance and disease incidence in three cotton growing regions, collected prior to 2013 planting, for the genetic diversity and abundance as influenced by soil type, environment and management practices and link it with disease incidence and suppression. Results from the 28S LSU rRNA sequencing based analysis indicated a total of 370 fungal genera in all the cotton soils and the top 25 genera in abundance accounted for the major portion of total fungal community. There were significant differences in the composition and genetic diversity of soil fungi between the different field sites from the three cotton growing regions. Results for diversity indices showed significantly greater diversity in the long-term crop rotation experiment at Narrabri (F6E) and experiments at Cowan and Goondiwindi compared to the Biofumigation and D1 field experiments at ACRI, Narrabri. Diversity was lowest in the soils under brassica crop rotation in Biofumigation experiment. Overall, the diversity and abundance of soil fungal community varied significantly in the three cotton growing regions indicating soil type and environmental effects. These results suggest that changes in soil fungal community may play a notable role in soilborne disease incidence in cotton.

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The cotton industry in Australia funds biannual disease surveys conducted by plant pathologists. The objective of these surveys is to monitor the distribution and importance of key endemic pests and record the presence or absence of new or exotic diseases. Surveys have been conducted in Queensland since 2002/03, with surveillance undertaken by experienced plant pathologists. Monitoring of endemic diseases indicates the impact of farming practices on disease incidence and severity. The information collected gives direction to cotton disease research. Routine diagnostics has provided early detection of new disease problems which include 1) the identification of Nematospora coryli, a pathogenic yeast associated with seed and internal boll rot; and 2) Rotylenchulus reniformis, a plant-parasitic nematode. This finding established the need for an intensive survey of the Theodore district revealing that reniform was prevalent across the district at populations causing up to 30% yield loss. Surveys have identified an exotic defoliating strain (VCG 1A) and non-defoliating strains of Verticillium dahliae, which cause Verticillium wilt. An intensive study of the diversity of V. dahliae and the impact these strains have on cotton are underway. Results demonstrate the necessity of general multi-pest surveillance systems in broad acre agriculture in providing (1) an ongoing evaluation of current integrated disease management practices and (2) early detection for a suite of exotic pests and previously unknown pests.

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Field trials evaluating several parameters of growth, fruit yield and quality of 'Hass' avocado grafted to different rootstocks were established in 2004-2005 in four different growing regions of Australia. Fruit were harvested in three seasons from 2008, ripened and assessed for severity and incidence of anthracnose and stem end rot diseases. Peel samples were collected at harvest and analysed for concentrations of the cations (N, K, Ca, Mg). Rootstock significantly affected marketability of fruit (no stem end rot and less than 5% anthracnose) in 58% of the total number of trials evaluated, with better quality fruit harvested from 'Hass' grafted to Guatemalan or West Indian rootstocks such as 'A10' or 'Velvick'. Fruit quality was frequently poor from trees grafted to Mexican race rootstocks, regardless of growing location. Correlation analyses showed that fruit from rootstocks with superior fruit quality was often associated with lower skin N and higher Ca concentrations. There were significant positive correlations between anthracnose and skin N or N:Ca ratio in 75% of trials evaluated. There was a significant negative correlation between anthracnose and Ca in 42% of trials. The correlations between stem end rot and skin N (positive) or Ca (negative) were each significant in 42% of trials. Based on the results in this project, N:Ca ratios in the skin of unripe avocado fruit at harvest may provide one of the best indicators of potential postharvest disease in ripe fruit, and may have implications for fertiliser regimes.

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The eggplant ( Solanum aethiopicum ) is the species of the Solanum genus, whose geographical distribution is broadest. It is grown throughout tropical Africa, and includes three groups of cultivars commonly called African or indigenous eggplant. Kumba group or “bitter eggplant” is an important Solanaceous vegetable crop in Burkina Faso. The objective of this study was to determine genetic variability, strength of association and level of heritability among agronomic interest traits. Phenotypic and genotypic variations and heritability of 14 traits were estimated in 61 accessions at Institut de Développement Rural (IDR), Gampela in Burkina Faso. High phenotypic and genotypic coefficients of variation were observed for fruit diameter, number of seeds per fruit, fruit weight, leaf blade length and width, and height at flowering. In addition, genetic and phenotypic variances were high for the number of seed, fruit weight, plant height at flowering and days to 50% flowering. High heritability estimates were recorded for all traits. Fruit weight showed a positive association with fruit diameter and thickness. The fifty percent flowering cycle registered positive correlations with plant height and fruit diameter. Fruit number showed a negative association with fruit weight and diameter, and 50% flowering cyle.

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Motile Aeromonas are the most common bacteria of freshwater in the world that cause disease in fish and other cold-blooded and warm-blooded hosts. Among this group of bacteria, Aeromonas hydrophila is important in causing complications such as fin rot, skin ulcers and lethal hemorrhagic septicemia in fish. Several virulence factors involved in the pathogenesis of Aeromonas hydrophila, including extracellular enzymes (protease, lipase, elastase, gelatinase and nuclease) and toxins. From the exotoxins, hemolysin, aerolysin and cytolytic enterotoxin play an important role in pathogenesis. Detection of virulence markers by PCR as a key component of determining the pathogenesis of the bacteria and using indigenous vaccines for better immunization against this disease is important. In this study, a total of 200 fanned carps (126 common carp. 39 silver carp and 35 of grass carp) with symptoms suspected aeromonas septicemia were isolated from Khouzestan province farms. 125 bacteria belong to Aeromonas genus detected by biochemical and PCR methods. 31 of all isolates recognized as Aeromonas hydrophila with biochemical methods, I6srRNA detection and Lipase genes. Results showed that the role of Aeromonas sp. and Aeromonas hydrophila in fish with disease symptoms were 62.5% and 15.5% respectively. By using specific primers, three virulence genes including hemolysin, aerolysine and cytolytic enterotoxin were detected in these confirmed isolates, that 18 isolates (58/06%) hemolysin positive (hlyA +), 16 isolates (51/61%) aerolysine positive (aerA+) and 23 isolates (74/19%) for cytolytic enterotoxin gene (act+) were positive. The result of present study showed that most of the confirmed isolates genotype was hlyA+ act- with frequency equal to 51/61%. For investigating the protection effect of acut strain of bacteria, UV inactivated bacterin was used.

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O objetivo deste estudo foi avaliar o efeito da termoterapia (56 ºC por 6 min) e quimioterapia (propiconazole 250 ml.l-1) associado com temperatura de armazenamento (temperatura ambiente, 18 ºC e 13 ºC) no controle de podridões de bananas (Musa spp.) 'Prata-Anã' (AAB) em pós-colheita. Os tratamentos apresentaram diferenças significativas na percentagem de área lesionada por fruto, perda de peso e coloração externa da casca em todas as temperaturas de armazenamento. A quimioterapia e a combinação termoterapia e quimioterapia evitaram a manifestação de podridões nas três condições de armazenamento, enquanto a termoterapia reduziu a percentagem de área lesionada por fruto de 98% para 11% em temperatura ambiente, de 8% para 7% em 18 ºC e de 10% para 0% em 13 ºC, sendo mais eficiente sob a temperatura de 13 ºC. Frutos não tratados perderam 25%, 10% e 3% de peso e atingiram a cor 7, 5 e 1 em temperatura ambiente, 18 ºC e 13 ºC, respectivamente. Frutos tratados com termoterapia e quimioterapia perderam 24, 11 e 5% e 20, 10 e 3%, e atingiram índice médio de cor 4 e 3,5, respectivamente. O período de conservação foi estendido para 18, 24 e 45 dias em temperatura ambiente, 18 ºC e 13 ºC, respectivamente. A combinação dos métodos evitou a manifestação de podridões, reduziu a perda de peso e manteve a cor da casca e a qualidade dos frutos.

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O objetivo desse estudo foi determinar a tolerância de banana (Musa spp.) 'Prata-Anã' (AAB) e do fungo Colletotrichum musae à termoterapia no controle de podridões em pós-colheita. Experimentos in vivo e in vitro foram instalados em delineamento inteiramente casualizado, seguindo um esquema fatorial 4x5 (temperatura x tempo). Os tratamentos consistiram na imersão dos frutos (buquês) e do fungo (esporos e micélio) em água aquecida a 47, 50, 53 e 56 ºC, durante 0, 3, 6, 9 e 12 min. A exposição dos frutos a 56 ºC durante 9 min causou escurecimento da casca nas extremidades dos frutos, porém, as características físicas e químicas dos frutos não foram alteradas pelos tratamentos. Frutos inoculados e tratados a 56 ºC durante 6 min não apresentaram podridões nem escurecimento da casca, enquanto aqueles não tratados apresentaram 64% da área lesionada / fruto. A partir das combinações 53 ºC / 9 mi. e 56 ºC / 3 min a germinação de esporos foi reduzida para 4% e 0%, respectivamente. A combinação 56 ºC / 12 min reduziu, mas não paralisou o crescimento micelial. O tratamento 56 ºC / 6 min retardou mas não paralisou o crescimento micelial in vitro, porém foi efetivo no controle completo das podridões in vivo. Esse tratamento evitou a manifestação de podridões no inverno (maio), mas não no verão (novembro), mostrando-se influenciado pelas condições climáticas próximas à colheita dos cachos. A termoterapia pode ser recomendada para controle de podridão em pós-colheita de banana devendo ser ajustada para diferentes estações do ano.

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Neste trabalho testou-se o potencial antagonista de 16 fungos endofíticos isolados de videiras (Vitis vinifera L.), de castas representativas do Alentejo produzidas em modo de proteção integrada e em modo biológico, contra Guignardia bidwellii. Os isolados identificados após ITS-PCR e sequenciação pertencem aos géneros Epicoccum, Alternaria, Botrytis, Athelia, Phoma e Gibberella. Os isolados testados mostraram atividade antagonista contra G. bidwellii quer por inibição direta, quer através da produção de compostos voláteis, à exceção dos dois isolados de B. cinerea. No entanto, todos os isolados produziram alguns compostos voláteis com reconhecida atividade antimicrobiana, tais como benzaldeído, 3-metil-1-butanol e derivados de ácido propanoico. Foi ainda observado que seis dos isolados produziram também metabolitos não voláteis com capacidade de inibir o crescimento de G. bidwellii. Os resultados obtidos vêm mostrar o potencial dos fungos endofíticos como agentes de luta biológica no controlo de G. bidwellii, podendo constituir novas alternativas no âmbito de Proteção de Plantas; ABSTRACT: Endophytic fungi present in grapevines (Vitis vinifera L.) with the ability to inhibit the growth of the causal agent of black rot (Guignardia bidwellii) In this work the antagonistic potential of 16 endophytic grapevine fungi isolates (Vitis vinifera L.), from representative cultivars of the Alentejo region produced either under integrated pest management or organic mode, was tested against Guignardia bidwellii. Isolates were identified through ITS-PCR and sequencing, as belonging to the genera Epicoccum, Alternaria, Botrytis, Athelia, Phoma and Gibberella. Isolates showed antagonist activity against G. bidwellii either by direct inhibition or through the production of volatile compounds, with the exception of two isolates of B. cinerea. Nevertheless, all isolates produced volatile compounds with known antimicrobial activity such as benzaldehyde, 3-methyl-1-butanol and propionic acid derivatives. Additionally, six isolates produced non-volatile metabolites with the ability to inhibit G. bidwellii growth. These results show the potential that endophytic fungi have as agents for biological control of G. bidwellii, opening new options in the field of Plant Protection.

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Cassava root is the main staple for 70% of the population in Mozambique, particularly in inaccessible rural areas, but is known to be low in iron. Anaemia is a public health problem in mothers and preschool children in Mozambique and up to 40% of these cases are probably due to dietary iron deficiency. The World Health Organization (WHO) and Food and Agriculture Organization of the United Nations (FAO) recognize the fortification of foodstuff as an effective method to remedy dietary deficiencies of micronutrients, including iron. Cassava mahewu, a non-alcoholic fermented beverage is prepared at subsistence level from cassava roots using indigenous procedures. The aim of the study was to standardize mahewu fermentation and investigate if the type of cassava fermented, or the iron compound used for fortification affected the final product. Roots of sweet and bitter varieties of cassava from four districts (Rapale, Meconta, Alto Molocue and Zavala) in Mozambique, were peeled, dried and pounded to prepare flour. Cassava flour was cooked and fermented under controlled conditions (45°C for 24 h). The fermentation period and temperature were set, based on the findings of a pilot study which showed that an end-point pH of about 4.5 was regularly reached after 24 h at 45°C. Cassava mahewu was fortified with ferrous sulfate (FeSO4.7H2O) or ferrous fumarate (C4H2FeO4) at the beginning (time zero) and at the end of fermentation (24 h). The amount of iron added to the mahewu was based on the average of the approved range of iron used for the fortification of maize meal. The mean pH at the endpoint was 4.5, with 0.29% titratable acidity. The pH and acidity were different to those reported in previous studies on maize mahewu, whereas the solid extract of 9.65% was found to be similar. Lactic acid bacteria (LAB) and yeast growth were not significantly different in mahewu fortified with either of the iron compounds. There was no significant difference between cassava mahewu made from bitter or sweet varieties. A standard method for preparation and iron fortification of cassava mahewu was developed. It is recommended that fortification occurs at the end of fermentation when done at household level.

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Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL

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Estudou-se a influencia de dois metodos de irrigacao, dois metodos e duas formulas de adubacao, na cultura do tomate industrial (Lycopersicon esculentum Mill), cultivar Rossol (VFN) usando-se "faixas sub-sub-divididas" em oito repeticoes. Por ocasiao da colheita, foi feita a classificacao, contagem e pesagem dos frutos comerciaveis, verificaram-se diferencas significativas para metodos de adubacao e sua interacao com metodos de irrigacao, ao nivel de probabilidade de 5 e 1%, respectivamente. O metodo de adubacao em sulco apresentou maior rendimento que em cova, quanto irrigado por aspersao, ocorrendo o contrario quando a irrigacao foi por sulco. A producao de frutos com podridao apical foi afetada pelos metodos de irrigacao, metodos e formulas de adubacao, e interacoes, tendo sido encontradas diferencas significativas a niveis de 0,05% de probabilidade. No metodo de irrigacao por aspersao, ocorreu a menor percentagem de frutos com este disturbio fisiologico.