Study and assessment of compost of different organic mixtures and effect of organic compost tea on plant diseases

Four compost treatments representing different organic mixtures were studied: - Treatment T1: 100% cattle manure - Treatment T2: 80% cattle manure and 20% sheep manure - Treatment T3: 70% cattle manure, 20% sheep manure and 10% poultry manure. - Treatment T4: 50% cattle manure, 20% sheep manure, 20% poultry manure and 10% crushed wheat straw. The results showed that the temperature was higher for the 4th treatment which was richer in carbon than the other treatments. The initial alkaline pH decreases for all treatments and approaches neutrality at the end of composting process, essentially for the first treatment. There is also a decrease in the carbon / nitrogen ratio. At the maturity stage, a compost tea was prepared from different composts after five days extraction period. The four compost teas were tested on different plant pathogens: Fusarium roseum var sambucinum, Fusarium oxysporum, Fusarium oxysporum, Fusarium solani var coeruleum, Phytophtora erythroseptica and Rhizoctonia solani. All the treatments were efficient against these pathogens and especially the 4th treatment which considerably reduces also the dry rot of Fusarium solani in potato tubers during storage. This is considered an important result since Fusarium solani seems to be the most important pathogen in Tunisian soils. Our studies should be carried out in order to determine the better combination of organic mixtures, the better method of compost tea extraction (aerobic or anaerobic), the optimal period of extraction and doses to be used

Exploring bioactivities in artemisia annua L. extracts: extraction method and solvent screening

Mestrado de dupla diplomação com a Université Libre de TunisArtemisinin, the major active ingredient in Artemisia annua L., has been used as an antimalarial ingredient and is gaining popularity for its antiviral characteristics. Furthermore, some recent articles revealed that this important molecule could be beneficial against the Sars-CoV-2 virus, brain tumours, covid-19, and other diseases. Recently, there has been a push to enhance artemisinin extraction in terms of energy costs and solvent efficiency. Therefore, various innovative procedures, such as supercritical fluid extraction, pressurized solvent extraction, microwave-assisted extraction, and ultrasound-assisted extraction, are being studied and combined with several innovative solvents. Most extraction solvents have significant toxicity, flammability, and limited selectivity, and large-scale use of these solvents has a negative impact on the environment. As a result, new extraction processes less harmful to the environment are being developed. For example, some green solvents, such as ionic liquids and deep eutectic solvents, have been proposed for artemisinin extraction. The concept of green chemistry seeks to eliminate or reduce harmful compounds in chemical applications. This report will include an evaluation of alternate extraction techniques, considering artemisinin yield, in addition to examining the potentialities of green solvents after a preliminary study with ethanol 80/20. It is essential knowledge to select the method and solvents to prepare extracts from Artemisia annua L. that will be studied in terms of several bioactivities, including antimalarial.A artemisinina, o principal ingrediente ativo da Artemisia annua L., tem sido usada como um ingrediente antimalárico e está ganhando popularidade por suas características antivirais. Além disso, alguns artigos recentes revelaram que esta importante molécula pode ser benéfica contra o vírus Sars-CoV-2, tumores cerebrais, covid-19 e outras doenças. Recentemente, houve um impulso para melhorar a extração de artemisinina em termos de custos de energia e eficiência de solventes. Portanto, vários procedimentos inovadores, como extração de fluido supercrítico, extração de solvente pressurizado, extração assistida por microondas e extração assistida por ultra-som, estão sendo estudados e combinados com vários solventes inovadores. A maioria dos solventes de extração tem toxicidade significativa, inflamabilidade e seletividade limitada, e o uso em larga escala desses solventes tem um impacto negativo no meio ambiente. Como resultado, novos processos de extração menos prejudiciais ao meio ambiente estão sendo desenvolvidos. Por exemplo, alguns solventes verdes, como líquidos iônicos e solventes eutéticos profundos, foram propostos para a extração de artemisinina. O conceito de química verde visa eliminar ou reduzir compostos nocivos em aplicações químicas. Este relatório incluirá uma avaliação de técnicas alternativas de extração, considerando o rendimento de artemisinina, além de examinar as potencialidades dos solventes verdes após um estudo preliminar com etanol 80/20. É essencial o conhecimento para selecionar o método e solventes para preparar extratos de Artemisia annua L. que serão estudados em termos de várias bioatividades, incluindo antimalárico