scholarly journals Application of Allelopathy in Crop Production

2021 ◽  
Author(s):  
Wasan S. Hussain ◽  
Mahmoud M. Abbas

Need for food production has been increasing greatly in recent years throughout the world. The interest on the supply of quality of food has also increased, but a significant loss of crop production was observed annually, especially the main cereal crops, including rice, wheat and maize, due to the presence of weeds accompanying them in the growing season. Allelopathy has emerged as an alternative approach to solve problem agriculture that including: crop rotations, intercropping, crop residue incorporation and aqueous extracts all that used to explore allelopathy for pest management, enhancement of growth and crop production. As will allelopathic consider as weeds, insect and diseases natural control. Secondary metabolites biosynthesis of at high rates have a great role in provides defense against abiotic stresses. In plant rhizosphere allelochemicals exuded improve nutrient acquisition through the processes of solublization; biological nitrification; chelation and selected retention. In this chapter, application of the allelopathic phenomenon in crop production is discussed and his roller in managing agricultural pests and improving the productivity of agricultural systems. It was found that allelochemicals promote plant growth and production at low concentration; however it can suppress the growth if applied at high concentrations, for that can be used allelopathic compounds for weed control by used high concentrations of plant residues or aqueous extracts of plant.

2019 ◽  
Vol 58 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Hellem Cristina Silva Carneiro ◽  
Noelly Queiroz Ribeiro ◽  
Rafael Wesley Bastos ◽  
Daniel Assis Santos

Abstract The chemical control of pests and weeds is employed to improve crop production and the quality of agricultural products. The intensive use of pesticides, however, may cause environmental contamination, thus altering microbial communities. Cryptococcus gattii is an environmental yeast and the causative agent of cryptococcosis in both humans and animals. Up to this day, the effects of agrochemicals on human pathogens living in nature are still widely unknown. In this work, we analyzed the susceptibility of C. gattii to nonfungicide agrochemicals (herbicides and insecticides). Microdilution and drug-combination susceptibility tests were performed for the herbicides flumioxazin (FLX), glyphosate (GLY), isoxaflutole (ISO), pendimethalin (PEND), and also for the insecticide fipronil (FIP). Moreover, these compounds were combined with the clinical antifungals amphotericin B and fluconazole. The MIC values found for the agrochemicals were the following: < 16 μg/ml, for flumioxazin; 128 to 256 μg/ml, for FIP, ISO, and PEND; and >256 μg/ml, for GLY. Synergistic and antagonistic interactions, depending on the strain and concentration tested, were also observed. All strains had undergone adaptation to increasing levels of agrochemicals, in order to select the less susceptible subpopulations. During this process, one C. gattii strain (196 L/03) tolerated high concentrations (50 to 900 μg/ml) of all pesticides assessed. Subsequently, the strain adapted to flumioxazin, isoxaflutole and pendimethalin showed a reduction in the susceptibility to agrochemicals and clinical antifungals, suggesting the occurrence of cross-resistance. Our data point to the risk of exposing C. gattii to agrochemicals existing in the environment, once it might impact the susceptibility of clinical antifungals.


Irriga ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 562-589
Author(s):  
Fernanda Lamede Ferreira de Jesus ◽  
Otávio Neto Almeida Santos ◽  
Marcus Vinicius Talamini Junior ◽  
Tamara Maria Gomes ◽  
Fabrício Rossi ◽  
...  

ÁGUAS RESIDUÁRIAS PARA IRRIGAÇÃO NO BRASIL: UMA ABORDAGEM QUÍMICA, FÍSICA E MICROBIOLÓGICA     FERNANDA LAMEDE FERREIRA DE JESUS1; OTÁVIO NETO ALMEIDA SANTOS2; MARCUS VINICIUS TALAMINI JUNIOR3; TAMARA MARIA GOMES4; FABRÍCIO ROSSI5 E RODRIGO MÁXIMO SÁNCHEZ ROMÁN6   1 Departamento de Engenharia Agrícola, Universidade Federal Rural da Amazônia, Rod. PA 140, CEP. 68680-000 Tomé-Açu, Pará, Brasil, [email protected] 2 Departamento de Engenharia de Biossistemas, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, Av. Pádua Dias, 235, CEP 13418-900, Piracicaba, São Paulo, Brasil, [email protected] 3 Department of Agriculture and Life Sciences, Lincoln University, 85084 Ellesmere Junction Road, Lincoln, POBOX 7647, Canterbury, New Zealand, [email protected] 4 Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, R. Duque de Caxias, 225 - Jardim Elite, CEP. 13635-900, Pirassununga, São Paulo, Brasil, [email protected] 5 Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, R. Duque de Caxias, 225 - Jardim Elite, CEP. 13635-900, Pirassununga, São Paulo, Brasil, fabrí[email protected] 6 Departamento de Engenharia Rural e Socioeconomia, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista “Júlio de Mesquita Filho”, Av. Universitária, nº 3780 - Altos do Paraíso, CEP. 18610-034, Botucatu, São Paulo, Brasil, [email protected]     1 RESUMO   Os principais atributos a serem avaliados na qualidade da água residuária para irrigação contemplam os parâmetros físicos, químicos e biológicos, que definem o potencial para uso. As águas residuárias podem conter contaminantes, os quais podem ocasionar efeitos adversos no solo, nas plantas e nas águas subterrâneas se estiverem presentes em concentrações elevadas. O objetivo deste trabalho foi discutir as principais características que influenciam na qualidade da água residuária destinada à irrigação por meio de levantamento de informações disponíveis na literatura específica. O uso de efluentes para fins de irrigação requer uma abordagem mais cautelosa e o estudo sobre o mesmo ainda é incipiente. Os resultados obtidos nas pesquisas revelam que diversas culturas podem ser irrigadas com águas residuárias, quando devidamente tratadas. Este fato, ratifica a importância de se adotar uma política de reuso ainda mais específica no que diz respeito à utilização de águas residuárias em diversas atividades agrícolas, principalmente pela irrigação. Todavia, ainda existem diversos problemas relacionados a essa prática, sendo necessários mais estudos que contribuam para desenvolvimento da agricultura, visando à conservação dos recursos naturais, produção das culturas e segurança a saúde.   Palavras chave: Recurso hídrico, efluente, agricultura, contaminação, reuso.     JESUS, F. L. F.; SANTOS, O. N. A.; TALAMINI JUNIOR, M. V; GOMES, T. M.; ROSSI, F.; SÁNCHEZ-ROMÁN, R. M. WASTEWATER FOR IRRIGATION IN BRAZIL: A CHEMICAL, PHYSICAL AND MICROBIOLOGICAL APPROACH     2 ABSTRACT   The main attributes to be evaluated in irrigation water quality include  physical, chemical and biological parameters that define the potential for use. Wastewater may contain contaminants, which may cause adverse effects on the soil, plants and groundwater if they are present at high concentrations. The objective of this work was to discuss the main characteristics that influence the quality of the wastewater destined to  irrigation by means of information gathering available in the specific literature. The use of effluents for irrigation requires a more cautious approach and its study of is still incipient. The results obtained in the surveys reveal that several crops can be irrigated with wastewater when properly treated. This fact confirms the importance of adopting an even more specific reuse policy regarding the use of wastewater in various agricultural activities, mainly through irrigation. However, there are still several problems related to this practice, and further studies are needed that contribute to the development of agriculture, aiming at the conservation of natural resources, crop production and health security.   Keywords: Water resource, effluent, agriculture, contamination, reuse.


2020 ◽  
Vol 25 (42) ◽  
pp. 4464-4485 ◽  
Author(s):  
Katarzyna Kluszczyńska ◽  
Liliana Czernek ◽  
Wojciech Cypryk ◽  
Łukasz Pęczek ◽  
Markus Düchler

Background: Exosomes open exciting new opportunities for advanced drug transport and targeted release. Furthermore, exosomes may be used for vaccination, immunosuppression or wound healing. To fully utilize their potential as drug carriers or immune-modulatory agents, the optimal purity of exosome preparations is of crucial importance. Methods: Articles describing the isolation and purification of exosomes were retrieved from the PubMed database. Results: Exosomes are often separated from biological fluids containing high concentrations of proteins, lipids and other molecules that keep vesicle purification challenging. A great number of purification protocols have been published, however, their outcome is difficult to compare because the assessment of purity has not been standardized. In this review, we first give an overview of the generation and composition of exosomes, as well as their multifaceted biological functions that stimulated various medical applications. Finally, we describe various methods that have been used to purify small vesicles and to assess the purity of exosome preparations and critically compare the quality of these evaluation protocols. Conclusion: Combinations of various techniques have to be applied to reach the required purity and quality control of exosome preparations.


Metabolites ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 338
Author(s):  
Cameron Haswell ◽  
Ajmol Ali ◽  
Rachel Page ◽  
Roger Hurst ◽  
Kay Rutherfurd-Markwick

Metabolic syndrome (MetS) is a group of metabolic abnormalities, which together lead to increased risk of coronary heart disease (CHD) and type 2 diabetes mellitus (T2DM), as well as reduced quality of life. Dietary nitrate, betalains and anthocyanins may improve risk factors for MetS and reduce the risk of development of CHD and T2DM. Beetroot is a rich source of dietary nitrate, and anthocyanins are present in high concentrations in blackcurrants. This narrative review considers the efficacy of beetroot and blackcurrant compounds as potential agents to improve MetS risk factors, which could lead to decreased risk of CHD and T2DM. Further research is needed to establish the mechanisms through which these outcomes may occur, and chronic supplementation studies in humans may corroborate promising findings from animal models and acute human trials.


1995 ◽  
Vol 23 (1) ◽  
pp. 61-73
Author(s):  
Coenraad Hendriksen ◽  
Johan van der Gun

In the quality control of vaccine batches, the potency testing of inactivated vaccines is one of the areas requiring very large numbers of animals, which usually suffer significant distress as a result of the experimental procedures employed. This article deals with the potency testing of diphtheria and tetanus toxoids, two vaccines which are used extensively throughout the world. The relevance of the potency test prescribed by the European Pharmacopoeia monographs is questioned. The validity of the potency test as a model for the human response, the ability of the test to be standardised, and the relevance of the test in relation to the quality of the product are discussed. It is concluded that the potency test has only limited predictive value for the antitoxin responses to be expected in recipients of these toxoids. An alternative approach for estimating the potency of toxoid batches is discussed, in which a distinction is made between estimation of the immunogenic potency of the first few batches obtained from a seed lot and monitoring the consistency of the quality of subsequent batches. The use of animals is limited to the first few batches. Monitoring the consistency of the quality of subsequent batches is based on in vitro test methods. Factors which hamper the introduction and acceptance of the alternative approach are considered. Finally, proposals are made for replacement, reduction and/or refinement (the Three Rs) in the use of animals in the routine potency testing of toxoids.


2021 ◽  
Vol 11 (10) ◽  
pp. 4392
Author(s):  
Apolka Ujj ◽  
Kinga Percsi ◽  
Andras Beres ◽  
Laszlo Aleksza ◽  
Fernanda Ramos Diaz ◽  
...  

The use and quality analysis of household compost have become very important issues in recent years due to the increasing interest in local food production and safe, self-produced food. The phenomenon was further exacerbated by the COVID-19 pandemic quarantine period, which gave new impetus to the growth of small home gardens. However, the knowledge associated with making high-quality compost is often lacking in home gardeners. Therefore, the objective of this research was to find answers to the following questions: can the quality of backyard compost be considered safe in terms of toxicity and nutrient content? Can weed seed dispersion affect the usability of backyard compost? In general, can the circulation of organic matter be increased with the spread of home composting? In this study, 16 different house composts were analysed for stability, weed seed contamination, toxic elements, and nutrient content using analysis of variance. The results of the research showed that the quality properties of the composts (including their weed seed dispersion effect) were greatly influenced by the different techniques and raw materials used. The toxicity levels, as well as the content of macro and microelements, were within the parameters of safe-quality compost. The specific macronutrient (Ca, Mg) and micronutrient (Fe, Mn) contents of the tested composts have a similar and, in some cases, more favorable nutrient supply capacity in crop production than the frequently-used cow manure-based composts. With a plan of basic education on composting, there is potential to encourage farmyard composting.


2003 ◽  
Vol 17 (2) ◽  
pp. 85-115 ◽  
Author(s):  
David Thomas

In 1927 a study at King's College, University of London, of the chemical composition of foods was initiated by Dr McCance to assist with diabetic dietary guidance. The study evolved and was then broadened to determine all the important organic and mineral constituents of foods, it was financed by the Medical Research Council and eventually published in 1940. Over the next 51 years subsequent editions reflected changing national dietary habits and food laws as well as advances in analytical procedures. The most recent (5th Edition) published in 1991 has comprehensively analysed 14 different categories of foods and beverages. In order to provide some insight into any variation in the quality of the foods available to us as a nation between 1940 and 1991 it was possible to compare and contrast the mineral content of 27 varieties of vegetable, 17 varieties of fruit, 10 cuts of meat and some milk and cheese products. The results demonstrate that there has been a significant loss of minerals and trace elements in these foods over that period of time. It is suggested that the results of this study cannot be taken in isolation from recent dietary, environmental and disease trends. These trends are briefly mentioned and suggestions are made as to how the deterioration in the micronutrient quality of our food intake may be arrested and reversed.


Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 386
Author(s):  
Natalia Matłok ◽  
Józef Gorzelany ◽  
Adam Figiel ◽  
Maciej Balawejder

The study presents the effects of fertilisation on selected quality parameters of the dried material obtained from plants of lovage and coriander. During the crop production process, the plants were treated with two fertilisers containing substances potentially acting as elicitors. The dried material was obtained in course of a drying process carried out in optimum conditions and based on the CD-VMFD method which combines convective pre-drying (CD) at a low temperature (40 °C) with vacuum-microwave finish drying with the use of 240 W microwaves (VMFD). The quality of the dried material was evaluated through measurement of the total contents of polyphenols, total antioxidant potential (ABTS and DPPH method), and the profile of volatile compounds (headspace-solid phase microextractio-HS-SPME) as well as assessment of the colour. It was found that by applying first fertilisation (with organic components) it is possible to significantly increase the contents of both bioactive compounds and volatile substances responsible for the aroma. It was determined that the higher content of bioactive compounds was related to the composition of the first fertiliser, presumably the extract from common nettle. The study showed that the application of the first fertiliser contributed to enhanced quality parameters of the raw material obtained.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1290
Author(s):  
Danica Fazekašová ◽  
Gabriela Barančíková ◽  
Juraj Fazekaš ◽  
Lenka Štofejová ◽  
Ján Halas ◽  
...  

This paper presents the results of pedological and phytocoenological research focused on the detailed research of chemical parameters (pH, organic carbon, and nutrients), risk elements (As-metalloid, Cd, Co, Cr, Cu, Ni, Pb, and Zn), and species composition of the vegetation of two different peatlands on the territory of Slovakia—Belianske Lúky (a fen) and Rudné (a bog). Sampling points were selected to characterize the profile of the organosol within the peatland, the soil profile between the peatland and the agricultural land, and the soil profile of the outlying agricultural land, which is used as permanent grassland. Based on phytocoenological records, a semi-quantitative analysis of taxa in accordance with the Braun–Blanquet scale was performed. The study revealed that the thickness of the peat horizon of the fen in comparison with the bog is very low. In terms of the quality of organic matter, the monitored peatlands are dominated by fresh plant residues such as cellulose and lignin. Differences between individual types of peatlands were also found in the soil reaction and the supply of nitrogen to the organic matter of peat. The values of the soil exchange reaction were neutral on the fen, as well as slightly alkaline but extremely low on the bog. A significantly higher nitrogen supply was found in the organic matter of the fen in contrast to the bog. At the same time, extremely low content of accessible P and an above-limit content of As in the surface horizons were also found on the fen. From the phytocoenological point of view, 22 plant species were identified on the fen, while only five species were identified on the bog, which also affected the higher diversity (H’) and equitability (e). The results of the statistical testing confirmed the diversity of the studied peatlands and the different impact of environmental variables on plant diversity.


Author(s):  
M. Focker ◽  
H. J. van der Fels-Klerx ◽  
A. G. J. M. Oude Lansink

AbstractEarly 2013, high concentrations of aflatoxin M1 were found in the bulk milk of a few dairy farms in the Netherlands. These high concentrations were caused by aflatoxin B1 contaminated maize from Eastern Europe that was processed into compound feed, which was fed to dairy cows. Since the contamination was discovered in the downstream stages of the supply chain, multiple countries and parties were involved and recalls of the feed were necessary, resulting into financial losses. The aim of this study was to estimate the direct short-term financial losses related to the 2013 aflatoxin incident for the maize traders, the feed industry, and the dairy sector in the Netherlands. First, the sequence of events of the incident was retrieved. Then, a Monte Carlo simulation model was built to combine the scarce and uncertain data to estimate the direct financial losses for each stakeholder. The estimated total direct financial losses of this incident were estimated to be between 12 and 25 million euros. The largest share, about 60%, of the total losses was endured by the maize traders. About 39% of the total losses were for the feed industry, and less than 1% of the total losses were for the dairy sector. The financial losses estimated in this study should be interpreted cautiously due to limitations associated with the quality of the data used. Furthermore, this incident led to indirect long-term financial effects, identified but not estimated in this study.


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