scholarly journals The effect of biological and chemical control agents on the health status of the very early potato cultivar Rosara

2015 ◽  
Vol 55 (4) ◽  
pp. 389-395
Author(s):  
Bożena Cwalina-Ambroziak ◽  
Marta Maria Damszel ◽  
Małgorzata Głosek-Sobieraj

Abstract The external appearance and quality of table potatoes are determined, among other factors, by the health status of the plants during the growing season. Chemical control methods are often combined with biocontrol agents to effectively fight potato pathogens. Potatoes of the very early cultivar Rosara were grown in experimental plots. The plots were located in Tomaszkowo (NE Poland, 2007-2009). The experiment involved the following treatments: 1) biological control − mycorrhizal Glomus spp. inoculum was applied to the roots, − tubers were dressed and plants were sprayed with Polyversum three times during the growing season, 2) chemical control - at two-week intervals, plants were sprayed with the following fungicides: Infinito 687.5 SC and Tanos 50 WG, Valbon 72 WG and Tanos 50 WG. In the control treatment, potato plants were not protected against pathogens. During the growing season, the severity of late blight and early blight was evaluated on a nine-point scale. The composition of fungal communities colonising potato stems was analysed. The fungistatic properties of the fungicides used in the field experiment were evaluated in an in vitro test. The symptoms of infections caused by Phytophthora infestans and Alternaria spp. were significantly reduced in the treatment which used the integrated chemical and biological control. The least diverse fungal community was isolated from fungicide-treated plants. In the in vitro test, fungicides at all analysed concentrations inhibited the linear mycelial growth of selected pathogens.

1970 ◽  
Vol 17 (1) ◽  
Author(s):  
Ari L. Darmawan ◽  
ASEP IRAWAN ◽  
TIDI DHALIKA ◽  
ANA R. TARMIDI ◽  
MANSYUR ◽  
...  

Palm oil fiber has its potency as feed fiber source for ruminant, but contains high lignin and causes limited digestibility. This research was carried out to find the effect of soaking palm oil fiber in filtrated palm oil fruit bunch ash (FPOFBA) on in vitro digestibility. This experiment used a completely randomized design that repeated for 4times. Palm oil fruit bunch ash was mixed in water and entered into container for 24 hours within concentrations, consists of: 50, 100, 150 and 200 g/L. Moreover, this filtrate used to soak palm oil fiber for 3 hours. The processed products were analyzed for their level of lignin and crude fiber. Meanwhile, in vitro test was used to measure digestibility. It showed that soaking in filtrated palm oil fruit bunch ash gave significant effect to decrease level of lignin and crude fiber (P<0.05), and without soaking to improve digestibility of dry and organic matter compared to control treatment (P<0.05). Treatment with 150 g/L and 200 g/L using filtrated palm oil fruit bunch ash produced low level of lignin (P<0.05), as of: 17.25 and 18.53%. In contrast, within concentration of 150 g/L produced higher level of crude fiber compared to 200 g/L (46.04 vs. 43.87%). This seemed to have the same results in digestibility of dry and organic matter (P>0.05), such as 23.48 and 24.12% as well as 16.70 and 17.06 % in each. It can be concluded that soaked palm oil fiber with 150 g/L concentration of filtrated palm oil fruit bunch ash was more effective in improving digestibility.


2007 ◽  
Vol 13 (1) ◽  
pp. 79-84 ◽  
Author(s):  
Triwidodo Arwiyanto ◽  
Rahmad Asfanudin ◽  
Arif Wibowo ◽  
Toekidjo Martoredjo ◽  
Gembong Dalmadiyo

Lincat disease of temanggung tobacco could not be controlled effectively. One method of control which could be integrated with other measures is biological control. Bacillus is one of soil microorganisms which was not used widely as a biological control agent of plant disease. This report showed the results of the use of local isolates of Bacillus in controlling lincat disease of temanggung tobacco. As much as 91 isolates of Bacillus were directly tested in the field for their capability in suppressing lincat disease development. Six isolates, Ba-4, Ba-22, Ba-24, Ba-30, Ba-33, and Ba-41, could suppress lincat disease in the field. The result of in vitro test indicated that not all isolates which produced zone of inhibition in vitro could suppress disease development in the field. On the contrary, not all isolates which suppressed lincat disease in the field could inhibit the growth of pathogen in vitro. Isolate Ba-41, could suppressed lincat disease in the field and inhibited the growth of Meloidogyne incognita but not inhibited the growth of Ralstonia solanacearum.


2010 ◽  
Vol 10 (2) ◽  
pp. 123-130
Author(s):  
Andi Khaeruni ◽  
Gusti Ayu Kade Sutariati ◽  
Sri Wahyuni

Characterization and activities assay of rhizosphere bacteria from ultisol land for plant-growth promoting and biocontrol agents of soil-borne fungus pathogens under in vitro test.  Although many studies have been conducted to identify the specific traits of the plant growth-promoting and bioprotecting rhizobacteria (PGPBR), they were limited to studying specific PGPBR isolates from ultisol lands.  We selected 273 isolates from bulk soil and plant rhizosphere and examined them for a wide array traits that might inhibit the growth of plant pathogens and increase early cucumber growth in ultisol soil.  A subsample of 25 isolates, all positively produce chitinase and sellulose enzymes, 18 positively produce protease and 7 were fluorescens on KB medium under UV lighting.  All isolates could produce IAA and be able to solubilize phosphor in vitro test, 10 exhibited low level of nitrogenase activity. Futher test showed that out of 25 isolates, 12  inhibited F. oxysporum, P. capsici, R. solani and S. rolfsii in vitro.  All isolates increased seed germination, but only 5 isolates significanty increased early cucumber growth in ultisol soil. The results suggest that rhizobacteria be able to produce extracelluler enzymes, siderophore, ACC deasiminase, and IAA or those which are able to solubilize phosphor in vitro may be potential to be uses as biofertilizer and biological control agents in ultisol land.


1980 ◽  
Vol 44 (01) ◽  
pp. 006-008 ◽  
Author(s):  
D Bergqvist ◽  
K-E Arfors

SummaryIn a model using an isolated rabbit mesenteric preparation microvessels were transected and the time until haemostatic plugs formed was registered. Perfusion of platelet rich plasma gave no haemostasis whereas whole blood did. Addition of chlorpromazine or adenosine to the whole blood significantly prolonged the time for haemostasis, and addition of ADP to the platelet rich plasma significantly shortened it. It is concluded that red cells are necessary for a normal haemostasis in this model, probably by a combination of a haemodynamic and ADP releasing effect.The fundamental role of platelets in haemostatic plug formation is unquestionable but there are still problems concerning the stimulus for this process to start. Three platelet aggregating substances have been discussed – thrombin, adenosine diphosphate (ADP) and collagen. Evidence speaking in favour of thrombin is, however, very minimal, and the discussion has to be focused on collagen and ADP. In an in vitro system using polyethylene tubings we have shown that "haemostasis" can be obtained without the presence of collagen but against these results can be argued that it is only another in vitro test for platelet aggregation (1).To be able to induce haemostasis in this model, however, the presence of red blood cells is necessary. To further study this problem we have developed a model where haemostatic plug formation can be studied in the isolated rabbit mesentery and we have briefly reported on this (2).Thus, it is possible to perfuse the vessels with whole blood as well as with platelet rich plasma (PRP) and different pharmacological agents of importance.


2021 ◽  
Vol 9 (3) ◽  
pp. 478
Author(s):  
Ersilia Vita Fiscarelli ◽  
Martina Rossitto ◽  
Paola Rosati ◽  
Nour Essa ◽  
Valentina Crocetta ◽  
...  

As disease worsens in patients with cystic fibrosis (CF), Pseudomonas aeruginosa (PA) colonizes the lungs, causing pulmonary failure and mortality. Progressively, PA forms typical biofilms, and antibiotic treatments determine multidrug-resistant (MDR) PA strains. To advance new therapies against MDR PA, research has reappraised bacteriophages (phages), viruses naturally infecting bacteria. Because few in vitro studies have tested phages on CF PA biofilms, general reliability remains unclear. This study aimed to test in vitro newly isolated environmental phage activity against PA isolates from patients with CF at Bambino Gesù Children’s Hospital (OBG), Rome, Italy. After testing in vitro phage activities, we combined phages with amikacin, meropenem, and tobramycin against CF PA pre-formed biofilms. We also investigated new emerging morphotypes and bacterial regrowth. We obtained 22 newly isolated phages from various environments, including OBG. In about 94% of 32 CF PA isolates tested, these phages showed in vitro PA lysis. Despite poor efficacy against chronic CF PA, five selected-lytic-phages (Φ4_ZP1, Φ9_ZP2, Φ14_OBG, Φ17_OBG, and Φ19_OBG) showed wide host activity. The Φ4_ZP1-meropenem and Φ14_OBG-tobramycin combinations significantly reduced CF PA biofilms (p < 0.001). To advance potential combined phage-antibiotic therapy, we envisage further in vitro test combinations with newly isolated phages, including those from hospital environments, against CF PA biofilms from early and chronic infections.


1996 ◽  
Vol 24 (3) ◽  
pp. 325-331
Author(s):  
Iain F. H. Purchase

The title of this paper is challenging, because the question of how in vitro methods and results contribute to human health risk assessment is rarely considered. The process of risk assessment usually begins with hazard assessment, which provides a description of the inherent toxicological properties of the chemical. The next step is to assess the relevance of this to humans, i.e. the human hazard assessment. Finally, information on exposure is examined, and risk can then be assessed. In vitro methods have a limited, but important, role to play in risk assessment. The results can be used for classification and labelling; these are methods of controlling exposure, analogous to risk assessment, but without considering exposure. The Ames Salmonella test is the only in vitro method which is incorporated into regulations and used widely. Data from this test can, at best, lead to classification of a chemical with regard to genotoxicity, but cannot be used for classification and labelling on their own. Several in vitro test systems which assess the topical irritancy and corrosivity of chemicals have been reasonably well validated, and the results from these tests can be used for classification. The future development of in vitro methods is likely to be slow, as it depends on the development of new concepts and ideas. The in vivo methods which currently have reasonably developed in vitro alternatives will be the easiest to replace. The remaining in vivo methods, which provide toxicological information from repeated chronic dosing, with varied endpoints and by mechanisms which are not understood, will be more difficult to replace.


Author(s):  
Muhammad Faris Adrianto ◽  
Febri Annuryanti ◽  
Clive G. Wilson ◽  
Ravi Sheshala ◽  
Raghu Raj Singh Thakur

AbstractThe delivery of drugs to the posterior segment of the eye remains a tremendously difficult task. Prolonged treatment in conventional intravitreal therapy requires injections that are administered frequently due to the rapid clearance of the drug molecules. As an alternative, intraocular implants can offer drug release for long-term therapy. However, one of the several challenges in developing intraocular implants is selecting an appropriate in vitro dissolution testing model. In order to determine the efficacy of ocular implants in drug release, multiple in vitro test models were emerging. While these in vitro models may be used to analyse drug release profiles, the findings may not predict in vivo retinal drug exposure as this is influenced by metabolic and physiological factors. This review considers various types of in vitro test methods used to test drug release of ocular implants. Importantly, it discusses the challenges and factors that must be considered in the development and testing of the implants in an in vitro setup. Graphical abstract


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.


2006 ◽  
Vol 69 (12) ◽  
pp. 976-982 ◽  
Author(s):  
Nenad Ignjatović ◽  
Petar Ninkov ◽  
Vesna Kojić ◽  
Miloš Bokurov ◽  
Vladimir Srdić ◽  
...  

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