Selection of genetically diverse Trichoderma spp. isolates for suppression of Phytophthora capsici on bell pepper

2010 ◽  
Vol 56 (10) ◽  
pp. 864-873 ◽  
Author(s):  
Daniel P. Roberts ◽  
Jude E. Maul ◽  
Laurie F. McKenna ◽  
Sarah E. Emche ◽  
Susan L.F. Meyer ◽  
...  
Keyword(s):  
Phytophthora Capsici ◽  
Management Strategies ◽  
Bell Pepper ◽  
Control Measures ◽  
Disease Suppression ◽  
Significant Suppression ◽  
Trichoderma Spp ◽  
Rdna Cluster ◽  
Its1 Region ◽  
Significant Disease

Environmentally compatible control measures are needed for suppression of Phytophthora capsici on pepper. Twenty-three isolates of Trichoderma were screened for suppression of a mixture of 4 genetically distinct isolates of this pathogen on bell pepper ( Capsicum anuum ) in greenhouse pot assays. Of these 23 isolates, GL12, GL13, and Th23 provided significant suppression of P. capsici in at least 2 assays. These isolates were then compared with Trichoderma virens isolates GL3 and GL21 for suppression of this disease in the presence and absence of the harpin-based natural product Messenger. Isolates GL3 and Th23 provided significant disease suppression (P ≤ 0.05) in 3 of 4 assays, while GL12, GL13, and GL21 provided significant suppression in 2 of 4 assays. There was no apparent benefit from the application of Messenger. Phylogenetic analysis of these 5 isolates (based on the ITS1 region of the nuclear rDNA cluster and tef1), and an additional 9 isolates that suppressed P. capsici in at least 1 assay, separated isolates into 2 clades, with 1 clade containing GL3, GL12, GL13, and GL21. There were also 2 more distantly related isolates, one of which was Th23. We report here the identification of genetically distinct Trichoderma isolates for potential use in disease management strategies employing isolate combinations directed at suppression of P. capsici on pepper.

scholarly journals Improving Management Strategies of Plant Diseases Using Sequential Sensitivity Analyses

2019 ◽  
Vol 109 (7) ◽  
pp. 1184-1197 ◽  
Author(s):  
Loup Rimbaud ◽  
Sylvie Dallot ◽  
Claude Bruchou ◽  
Sophie Thoyer ◽  
Emmanuel Jacquot ◽  
...  
Keyword(s):  
Net Present Value ◽  
Management Strategies ◽  
Optimal Solution ◽  
Plant Diseases ◽  
Control Measures ◽  
Disease Suppression ◽  
Simultaneous Optimization ◽  
Disease Spread ◽  
Sensitivity Analyses ◽  
Plum Pox Virus

Improvement of management strategies of epidemics is often hampered by constraints on experiments at large spatiotemporal scales. A promising approach consists of modeling the biological epidemic process and human interventions, which both impact disease spread. However, few methods enable the simultaneous optimization of the numerous parameters of sophisticated control strategies. To do so, we propose a heuristic approach (i.e., a practical improvement method approximating an optimal solution) based on sequential sensitivity analyses. In addition, we use an economic improvement criterion based on the net present value, accounting for both the cost of the different control measures and the benefit generated by disease suppression. This work is motivated by sharka (caused by Plum pox virus), a vector-borne disease of prunus trees (especially apricot, peach, and plum), the management of which in orchards is mainly based on surveillance and tree removal. We identified the key parameters of a spatiotemporal model simulating sharka spread and control and approximated optimal values for these parameters. The results indicate that the current French management of sharka efficiently controls the disease, but it can be economically improved using alternative strategies that are identified and discussed. The general approach should help policy makers to design sustainable and cost-effective strategies for disease management.

scholarly journals Improving management strategies of plant diseases using sequential sensitivity analyses

2018 ◽  
Author(s):  
Loup Rimbaud ◽  
Sylvie Dallot ◽  
Claude Bruchou ◽  
Sophie Thoyer ◽  
Emmanuel Jacquot ◽  
...  
Keyword(s):  
Net Present Value ◽  
Control Strategies ◽  
Management Strategies ◽  
Optimal Solution ◽  
Plant Diseases ◽  
Control Measures ◽  
Disease Suppression ◽  
Disease Spread ◽  
Sensitivity Analyses ◽  
Plum Pox Virus

ABSTRACTImprovement of management strategies of epidemics is often hampered by constraints on experiments at large spatiotemporal scales. A promising approach consists of modelling the biological epidemic process and human interventions, which both impact disease spread. However, few methods enable the simultaneous optimisation of the numerous parameters of sophisticated control strategies. To do so, we propose a heuristic approach (i.e., a practical improvement method approximating an optimal solution) based on sequential sensitivity analyses. In addition, we use an economic improvement criterion, based on the net present value, accounting for both the cost of the different control measures and the benefit generated by disease suppression. This work is motivated by sharka (caused by Plum pox virus), a vector-borne disease of prunus trees (especially apricot, peach and plum) whose management in orchards is mainly based on surveillance and tree removal. We identified the key parameters of a spatiotemporal model simulating sharka spread and control, and approximated optimal values for these parameters. The results indicate that the current French management of sharka efficiently controls the disease, but can be economically improved using alternative strategies that are identified and discussed. The general approach should help policymakers to design sustainable and cost-effective strategies for disease management.

scholarly journals (30) Effects of Fungicides and Cultivar Resistance for Phytophthora capsici Control in Bell Pepper Production

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1076A-1076 ◽  
Author(s):  
Jamie R. Stieg ◽  
S. Alan Walters ◽  
Jason P. Bond ◽  
Mohammad Babadoost
Keyword(s):  
Phytophthora Capsici ◽  
Management Strategies ◽  
Management Program ◽  
Bell Pepper ◽  
Spray Application ◽  
Cultivar Resistance ◽  
Phytophthora Blight ◽  
Infested Field ◽  
Single Method ◽  
Improve Disease Control

Management strategies for Phytophthora blight (caused by Phytophthora capsici) in bell pepper production are limited and there is no single method that will consistently provide adequate control. Twelve bell pepper cultivars (including four marketed as resistant/tolerant to P. capsici) were transplanted into a P. capsici-infested field and were managed with or without fungicide applications. The fungicide applications consisted of: i) Mefenoxam (Ridomil Gold EC, 1.2 L/ha) at transplant; and ii) a spray application of Dimethomorph (Acrobat, 0.45 kg/ha) + Copper (Tenn-Cop, 3.6 L/ha) alternated with Manganese ethylenebisdithiocarbamate (Maneb, 2.8 kg/ha) + Copper (Tenn-Cop; 3.6 L/ha) at 10- to 14-day intervals. Regardless of cultivar, the standard fungicide program reduced the incidence of Phytophthora blight and resulted in greater yields and farm-gate revenues when compared to the no fungicide program. Across all cultivars, total farm-gate revenues per hectare were $6,773 and $3,674 for the standard fungicide program and the no fungicide program, respectively. For P. capsici-tolerant cultivars, farm-gate revenues improved with the use of the standard fungicide program by $1,316, $4,427, and $5,447 per hectare for `Aristotle X3R', `Revolution', and `Alliance', respectively, compared to no fungicide applications. Furthermore, farm-gate revenue for P. capsici-resistant `Paladin' was improved by $3,240 per hectare when a standard fungicide program was used. Results indicate that although plant resistance is an important component of a P. capsici bell pepper management program, the use of recommended fungicides could improve disease control and increase farm-gate revenues.

Effect of Financial Control Mechanisms on Performance of Income Generating Units in Selected Public Universities in Kenya

2019 ◽  
Vol 3 (V) ◽  
pp. 286-304
Author(s):  
Shadrack Musunkui Towett ◽  
Isaac Naibei ◽  
Williter Rop
Keyword(s):  
Risk Management ◽  
Internal Control ◽  
Public Universities ◽  
Management Strategies ◽  
Internal Audit ◽  
Simple Random Sampling ◽  
Target Population ◽  
Control Measures ◽  
Financial Control ◽  
Control Mechanisms

In an attempt to bridge the gap between the budgetary allocations and actual expenditures most universities have started income generating units with the aim of boosting their operational expenses. Whereas there is the potential of the use of Income Generating Units (IGUs) to generate additional funds, most universities still experience challenges in full implementation and realization of the revenue goal. This study therefore sought to determine the financial control mechanisms affecting performance of income generating units among selected public universities. The study sought to determine the effect of internal controls, credit policies, financial risk management and internal audit on performance of income generating units in selected universities. Targeted population was all the 290 employees in the IGU departments of selected public universities. The respondents were sampled using simple random sampling so as to enable equal representation of the target population without any biasness. Data collection was done using the questionnaire to ensure sufficient data was collected from the respondents. Descriptive statistics assisted in the determination of respondent’s views and opinions on every variable. Qualitative data was analysed using content analysis into meaningful, precise and comprehensive statements and presented in quotations. Data analysis was done using SPSS version 21 and data presented in form of figures and tables. The study ensured that all ethical considerations were considered by the study. The findings were that most employed Income Generating Units in Public Universities were Collection of rental fees, Evening and executive programs and Trainings of both short and long courses while the least was established to be Sales of memorabilia and books. All the financial control mechanism investigated namely internal audit, internal control measures, risk management strategies and credit policies had large extents of adoption in the selected universities. The results of the regression analysis showed that the financial control mechanisms investigated had a significant positive relationship on performance of the IGUs. Specifically, 47% of the variation of the performance of IGUs was established to be explained by the studied factors. The study concluded that the performance of the IGUs among the selected public universities was largely accounted for by the implemented financial control measures. Therefore effective financial control mechanisms is concluded to lead to better IGU performance whereas shortcomings in the financial control mechanisms is concluded to lead to diminished returns in the IGUs. The study recommended that the management in charge of the IGU department in the public universities to prioritize the formulation, implementation and monitoring of financial control mechanisms in the IGUs. To facilitate effective financial controls, the study recommended that the management especially those in the audit section to conduct regular checks and inspections on the IGUs. Additionally, frequent reforms were recommended to address the shortcomings experienced in integrating financial control measures in IGUs.

IPM—A Problem-based Learning Approach

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 509e-509
Author(s):  
Robert P. Rice
Keyword(s):  
Pest Control ◽  
Test Performance ◽  
Management Strategies ◽  
Ornamental Plants ◽  
Real Life ◽  
Problem Based Learning ◽  
Control Measures ◽  
Learning Approach ◽  
Pest Monitoring ◽  
Use Of Resources

The Cal Poly philosophy of “Learn and Understand by Doing” has been integrated with problem-based learning and the use of the latest technology to produce a class that closely simulates real-life pest control situations. Goals of the class, Disease and Pest Control Systems for Ornamental Plants, are to teach students pest monitoring, control and problem solving techniques, the use of resources including the internet and journals, and the use of the latest pest control equipment and application techniques. Students are shown pest situations and then work in groups to diagnose the problem, investigate management strategies, apply control measures, and monitor results. Weekly class presentations inform the class of the various projects and help to teach the class organization and presentation skills. Student evaluations and test performance have demonstrated that students achieve class objectives substantially better with the problem-based learning approach than with the previous lecture-based approach to the class.

scholarly journals Characterization of Antagonistic Bacillus methylotrophicus Isolated From Rhizosphere and Its Biocontrol Effects on Maize Stalk Rot

2019 ◽  
Vol 109 (4) ◽  
pp. 571-581 ◽  
Author(s):  
Xingkai Cheng ◽  
Xiaoxue Ji ◽  
Yanzhen Ge ◽  
Jingjing Li ◽  
Wenzhe Qi ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Disease Incidence ◽  
Field Trials ◽  
Control Measures ◽  
Disease Suppression ◽  
Effective Control ◽  
Stalk Rot ◽  
Bacillus Methylotrophicus ◽  
Transmission Electron ◽  
Potential Biocontrol Agent

Stalk rot is one of the most serious and widespread diseases in maize, and effective control measures are currently lacking. Therefore, this study aimed to develop a new biological agent to manage this disease. An antagonistic bacterial strain, TA-1, was isolated from rhizosphere soil and identified as Bacillus methylotrophicus based on morphological and biochemical characterization and 16S ribosomal RNA and gyrB gene sequence analyses. TA-1 exhibited a strong antifungal effect on the growth of Fusarium graminearum mycelium, with 86.3% inhibition at a concentration of 108 CFU per ml. Transmission electron microscopy showed that TA-1 could disrupt the cellular structure of the fungus, induce necrosis, and degrade the cell wall. Greenhouse and field trials were performed to evaluate the biocontrol efficacy of TA-1 on maize stalk rot, and the results of greenhouse experiment revealed that the bacterium significantly reduced disease incidence and disease index. Seeds treated with a 108 CFU ml−1 cell suspension had the highest disease suppression at 86.8%. Results of field trials show that seed bacterization with TA-1 could not only reduce maize stalk rot incidence but also increase maize height, stem diameter, and grain yield. The lipopeptide antibiotics were isolated from the culture supernatants of TA-1 and identified as surfactins and iturins. Consequently, B. methylotrophicus TA-1 is a potential biocontrol agent against maize stalk rot.

scholarly journals Growth and Yields of Bell Pepper and Winter Squash Grown with Organic and Living Mulches

1994 ◽  
Vol 119 (6) ◽  
pp. 1193-1199 ◽  
Author(s):  
Nancy E. Roe ◽  
Peter J. Stoffella ◽  
Herbert H. Bryan
Keyword(s):  
Cucurbita Pepo ◽  
Phytophthora Capsici ◽  
Bell Pepper ◽  
Pepper Plant ◽  
Arachis Glabrata ◽  
Organic Mulch ◽  
Small Seed ◽  
Raised Bed ◽  
Plant Stand ◽  
Winter Squash

Increasing disposal problems with polyethylene (PL) mulch and greater availability of compost prompted an investigation into the effects of using compost as a mulch on horizontal raised bed surfaces with living mulches (LMs) on vertical surfaces. Wood chips (WC), sewage sludge-yard trimming (SY) compost, and municipal solid waste (MW) compost were applied at 224 t·ha-1 on bed surfaces. Sod strips of `Jade' (JD) or `Floratam' (FT) St. Augustinegrass (Stenotaphrum secundatum Kuntze) or perennial peanut (Arachis glabrata Benth.) (PP) or seeds of a small, seed-propagated forage peanut (Arachis sp.) (SP) were established on the vertical sides of the raised beds before transplanting bell pepper (Capsicum annuum L.) into the beds. Phytophthora capsici reduced pepper plant stand in PL-mulched plots compared with organic mulch (OM) and LM. Despite the stand reduction, total pepper yields were highest in PL plots and, in the OM plots, decreased in the order SY > MW > WC. Early fruit yields and yield per plant were highest from plants in PL plots followed by SY. Among LMs, plants in SP plots produced highest early yields and FT produced the lowest. Plants in PL plots produced the largest fruit. When the same plots were seeded with winter (butternut) squash (Cucurbita pepo L.), plant stands were higher in MW than WC and SY. Squash yields were similar between PL and OM plots.

scholarly journals Physicochemical and Microbiological Water Quality Assessment of Aba Waterside River, Aba, Nigeria

2019 ◽  
Vol 3 (1) ◽  
pp. 142-148
Author(s):  
L. O. Bobor ◽  
C. M. Umeh
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Management Strategies ◽  
Oxygen Demand ◽  
Water Quality Monitoring ◽  
Control Measures ◽  
Fecal Coliforms ◽  
Water Quality Control ◽  
Inorganic Substances ◽  
The Impact

The indiscriminate disposal of industrial effluents and solid wastes in surface water bodies is detrimental to humans and aquatic organisms. Water quality monitoring is critical to identify pollutants of concern and develop effective management strategies. Hence, this study was conducted to assess the impact of waste disposal on the water quality of Aba Waterside River, Ogbor hill, Aba. Grab samples were collected upstream, midstream and downstream and some physicochemical and microbiological parameters were analyzed in accordance with standard methods for the analysis of water and wastewater. The results were compared with the Nigerian standard for drinking water quality and the national environmental effluent limitation regulations. Turbidity levels (10 -31mg/l) exceeded the maximum permissible levels for drinking water (5mg/l) and may be associated with higher levels of embedded disease-causing microbes and potentially harmful organic and inorganic substances. The biological oxygen demand midstream (1960mg/l) was remarkably high due to the effluent discharged from the abattoirs at that point. Fecal coliforms (3-198MPN/100ml) were detected in all samples, indicating the presence of other potentially harmful microorganisms. The findings of this study indicate that the water is unsuitable for direct drinking water purposes and stringent water quality control measures should be implemented.

Nano-Biosensors Tech and IPM in Plant Protection to Respond to Climate Change Challenges in Morocco

2020 ◽  
pp. 114-129
Author(s):  
Wafaa Mokhtari ◽  
Mohamed Achouri ◽  
Abdellah Remah ◽  
Noureddine Chtaina ◽  
Hassan Boubaker
Keyword(s):  
Plant Pathogens ◽  
Ad Hoc ◽  
Plant Protection ◽  
Point Of Care ◽  
Integrated Approach ◽  
Control Measures ◽  
Special Focus ◽  
Green Beans ◽  
Trichoderma Spp ◽  
Diagnostic Sensitivity And Specificity

In this chapter, the authors introduce two research axes: Part A, nano-biosensors as ad-hoc technologies designed to meet plant diagnostic sensitivity and specificity needs at point of care, and Part B, the study of the interaction of drought and infection stresses in crops investigating bio-control potential antagonists in developing integrated approach (IPM) for disease control measures in crops system. The first part will be revising most used nano-biosensors in plant pathogens detection using different platforms in greenhouses, on-field, and during postharvest. A special focus will be on optical and voltametric immuno/DNA sensors application in plant protection. The last part will present case studies of using nanoparticles functionalized with antibody/DNA for detecting pathogenic Pseudomonas sp, mosaic viruses, Botrytis cinereal, and Fusarium mycotoxins (DON). The second part will be interpreting experimental results of a case study on evaluating bio-control efficacy of local Trichoderma spp. using root dips treatment in Fusarium solani-green beans pathosystem as a model.

Sign in / Sign up

Export Citation Format

Share Document