1/26/2015. Overview. Types of soil-borne plant pathogens

Size: px
Start display at page:

Download "1/26/2015. Overview. Types of soil-borne plant pathogens"

Transcription

1 /6/5 PLP 644 Epidemiology of Plant Diseases Spring 5 Lecture 6: Influence of Pathogen on Disease Development Soil-borne Prof. Dr. Ariena van Bruggen Emerging Pathogens Institute and Plant Pathology Department, IFAS University of Florida at Gainesville Overview Types of soilborne plant Examples of soilborne Factors affecting root-pathogen interactions Pathogen characteristics that influence epidemic development Competitive saprotrophic ability and inoculum potential Quantification of soilborne inoculum DI:ID relationships Conclusions Types of soil-borne plant soil inhabitants competitive saprotrophic ability (on dead organic matter) wide host range secondary or of young plants root inhabitants Little or no competitive saprotrophic ability specialized parasites, primary small or wide host range Examples of ecological types of soilborne Soil inhabitant, good CSA: Pythium, Rhizoctonia, Fusarium; Rhizorhapis and Ralstonia (bacteria) Soil inhabitant, limited CSA: Phytophthora, Verticillium Examples of ecological types of soilborne Soil inhabitant, no CSA: Pratylenchus penetrans Root inhabitant, no CSA: Plasmodiophora, Meloidogyne Infection by soil-borne Some important terms: Rhizoplane- on the root surface Rhizosphere- near the root but within the influence of the root (from exudates, volatiles etc.) Spermoplane- on the surface of seed (in the soil) Spermosphere- near the seed in the soil Factors affecting infection: Saprophytic growth in soil, spermo- and rhizosphere Competitive saprophytic ability Inoculum potential Ability to colonize the spermo- or rhizoplane Ability to infect the roots

2 /6/5 Pathogen characteristics that influence epidemic development of soilborne diseases Pathogen population size (number of propagules) Level of aggressiveness and virulence Inoculum potential Reproduction (sexual, asexual, rate) Ecology Pesticide resistance (fungicides, antibiotics) Dispersal mechanisms Strategies determining the success of infection by soilborne The number of spores and their vitality = inoculum potential Inoculum potential = inoculum density x aggressivity inoculum density = # spores / g soil or meters of hyphae /g soil Aggressivity = number of infection units - can be determined only in bioassays! so: inoculum potential also can only be determined in bioassays quantification interpretation inoculum density easy difficult inoculum potential difficult easy Strategies determining the success of colonisation by soilborne Characteristics ( weapons ) of the colonist = competitive saprotrophic ability Competitive saprotrophic ability =all physiological characteristics that makes an organism suited to colonize dead organic matter Method to determine CSA Fusarium culmorum Cochliobolus 75 sativus Gaeumannomyces 5 graminis 5 5 inoculum added (vol. %) colonised pieces of straw Factors affecting the competitive saprotrophic ability fast germination of survival structures fast growth of mycelium fast formation of enzymes needed to break down the substrate production of antibiotics, toxins or bacteriocins that inhibit competitors tolerance for antibiotics etc. formed by other organisms able to survive unfavorable periods Quantification of soilborne inoculum Extraction and quantification of propagules from soil Soil dilution plating for fungi and bacteria Enrichment with organic matter before dilution plating Warcup plate method (spread soil on plate cover with agar) Anderson sampler with appropriate sieves on layers of petriplates Wet-sieving / flotation possibly in sucrose (sclerotia, nematodes) Disease tests with naturally infested soil Plant seeds / seedlings in soil in a dilution series with sterile soil Baiting techniques Place autoclaved leaves etc in soil, plate after incubation and count positive samples (not really quantitative; why not?) Quantification of soilborne inoculum Dilution end point and most probable number methods Mix field soil with sterilized soil at different ratios Place baits or plants in individual cups or wells Determine dilution at which no more infection occurs use MPN table or computer program to calculate MPN/ g dry soil Immunological techniques Soil extracts in ELISA tests with mono-/ polyclonal antibodies Immunomagnetic capture Test kits available, but quantification is still problematic DNA techniques Extraction of DNA; amplify by PCR with spec. primers (qualitative) Same but use quantitative or qpcr (also called real-time or rtpcr); this is semiquantitative

3 /6/5 A lot of discussion in 97 s, 8 s and 9 s Van der Plank (975 Principles of Plant Infection ): six basic types of responses for the DI:ID relationship ) Disease is directly proportional to inoculum dose (straight line passing through the origin (,); slope is infection efficiency; IE=constant) Data from Schein (964) In this case, the spores 8 neither interact nor 6 IE =.9 compete for sites. 4 Disease intensity Colonies cm Urediniospores Spore density cm - Six basic types of responses for the DI:ID relationship ) DI:ID decreases as inoculum increases; something limits IE (availability of susceptible host sites or inhibitory interactions among propagules) ) Antagonistic response: the DI decreases with increases in ID (accumulation of inhibitory products in the presence of crowded spores) Number of infections Number of spores Six basic types of responses for the DI:ID relationship 4) Synergistic response: DI:ID increases with increases in ID 5) ID has to exceed a certain threshold 4 before the first infection (a large number of spores is needed to attain the probability that one spore will reach a susceptible site 6) Impossible response where disease seemingly occurs without inoculum! (curves like #6 in the literature; be suspicious!) Number of infections 6 5 Number of spores Basic assumption under Van der Plank s curves: All propagules act independently, independent-action model Each organism has a certain probability of causing an infection Total probability of infection from a given dose is the statistical combination of the probabilities for all the individual organisms The model of independent action: y = N [ - exp(-ax)] y = number of infections, x = number of spores, N = total number of susceptible sites, and a = the rate parameter that determines the proportion of effective units of inoculum High values of a mean very efficient inoculum Low values of N mean low numbers of susceptible sites With high a and low N, the monomolecular DI:ID curve has a strong curvature DI:ID relationship: y = N [ - exp(-ax)] high a low a high N high a high N low a Ralph Baker (Colorado State Univ.) published extensively on the ID:DI relationship in the 97s and 98s, mainly of Rhizoctonia solani on radish Baker s concepts were severely criticized and a series of letters to the editor in Phytopathology resulted Four possible kinds of infection courts and their interaction with inoculum (Baker et al., Phytopathology 57:66-666): Fixed court non-motile inoculum e.g. hypocotyl and sclerotia; infection occurs by chance when a sclerotium is next to a suitable infection court based on the density of inoculum and the density of infection courts.

4 /6/5 Four possible kinds of infection courts and their interaction with inoculum (continued): fixed infection court- motile inoculum; e.g., hypocotyl and zoospores or growing hyphae moving infection court- non-motile inoculum; e.g., root tip and sclerotia moving infection court and motile inoculum; e.g., root tip and zoospores or growing hyphae. Moving infection courts and motile inoculum would reduce the distance between propagules and infection court and thus increase the likelihood of infection Pathogen propagules considered to be arranged in soil as points at the vertices of a tetrahedron (simplest geometric form to utilize all space efficiently) To describe the ID:DI relationship mathematically, they plotted log (I) [successful infections] vs. log (D) [distance between propagules]. The slopes for fixed inoculum (with either fixed or moving infection courts) was about.67 The slopes for motile inoculum were about. Baker interpreted the slopes of.67 as a rhizoplane effect and slopes of. as a rhizosphere effect. Rhizosphere rhizoplane hypothesis by Baker Baker et al. (Phytopathology 6:8-9): log [ln (/(-y))] vs. log (ID) to linearize many curves Most slopes had values either close to. or close to.67 Baker interpreted the log-log slopes of. as a rhizosphere effect and the slopes of.67 (/) as a rhizoplane effect Many plant pathologists who worked with soil-borne infections used Baker s analyses, but there were sceptics Grogan (UCD) called this transformation a triple log transformation Baker et al., 98 Rhizosphere-rhizoplane hypothesis - criticism by Grogan Van der Plank rejects Baker s / hypothesis because: root diseases actually do not differ from leaf diseases; / slopes are also found for leaf diseases. Baker s models do not predict ID:DI curves for known root diseases from prior work. Baker s models are based on three erroneous assumptions: a) spores are mathematical points in soil with no dimensions or volume; b) spores are uniformly distributed (vertices of a tetrahedron); c) infection is NOT restricted by the number of susceptible sites. 4

5 /6/5 DI:ID (or Pf:Pi) relationships for nematodes Various models relate final density of nematodes (Pf) after harvest of the crop to the initial density (Pi) before the crop is sown A common structure of these models is: /α is slope of curve in origin /β is horizontal asymptote Valid for cyst and root knot nematodes with one generation per season Van den Berg: also valid for migratory nematodes (Pratylenchus penetrans) DI-ID (or Pf:Pi) relationships for nematodes Van Den Berg used Pf:Pi relations for single crops to predict population dynamics and crop loss for four different crops in different rotations (used complex nonlinear models and Monte Carlo simulations) Van den Berg and Rossing, 5 Conclusion Many pathogen characteristics determine epidemic development by soilborne Which factors? What is competitive saprotrophic ability? How can you measure it? What is inoculum potential? How can you measure it? How can you quantify inoculum density? Which technique is best and why? What is the relationship between inoculum density and disease intensity? What was the DI:ID controversy about? 5

PLP 6404 Epidemiology of Plant Diseases Spring 2015

PLP 6404 Epidemiology of Plant Diseases Spring 2015 PLP 6404 Epidemiology of Plant Diseases Spring 2015 Ariena van Bruggen, modified from Katherine Stevenson Lecture 26: Crop loss assessment Yield levels and losses Theoretical yield The yield obtained under

More information

No matter the weather conditions, there will be problematic diseases every year. Which disease may change from year to year.

No matter the weather conditions, there will be problematic diseases every year. Which disease may change from year to year. No matter the weather conditions, there will be problematic diseases every year. Which disease may change from year to year. This presentation focuses on integrated pest management of corn and soybean

More information

PLP 6404 Epidemiology of Plant Diseases Spring 2015

PLP 6404 Epidemiology of Plant Diseases Spring 2015 PLP 6404 Epidemiology of Plant Diseases Spring 2015 Ariena van Bruggen, modified from Katherine Stevenson Lecture 25b: Epidemiology and disease management strategies. Reducing the rate of epidemic development

More information

Natacha MOTISI. Melen LECLERC. Dealing with the variability in biofumigation efficiency through epidemiological modelling

Natacha MOTISI. Melen LECLERC. Dealing with the variability in biofumigation efficiency through epidemiological modelling Natacha MOTISI Melen LECLERC Dealing with the variability in biofumigation efficiency through epidemiological modelling Plan I. Modes of action of a biofumigant crop II. Objectives III. Experiments IV.

More information

Canola Diseases. Kurtis Schroeder Department of Plant Pathology Washington State University Pullman, WA

Canola Diseases. Kurtis Schroeder Department of Plant Pathology Washington State University Pullman, WA Canola Diseases Kurtis Schroeder Department of Plant Pathology Washington State University Pullman, WA Outline General overview of disease situation Soilborne Diseases Rhizoctonia Sclerotinia Potential

More information

PLP 6404 Epidemiology of Plant Diseases Spring Lecture 23-24: Epidemiology and disease management strategies

PLP 6404 Epidemiology of Plant Diseases Spring Lecture 23-24: Epidemiology and disease management strategies PLP 6404 Epidemiology of Plant Diseases Spring 2015 Ariena van Bruggen, modified from Katherine Stevenson Lecture 23-24: Epidemiology and disease management strategies Lecture 23. Principles of Plant Disease

More information

Modeling and Quantitative Analysis of Biological Control Mechanisms

Modeling and Quantitative Analysis of Biological Control Mechanisms Ecology and Epidemiology Modeling and Quantitative Analysis of Biological Control Mechanisms Douglas I. Rouse and Ralph Baker Former Research Assistant and Professor of Botany and Plant Pathology, respectively,

More information

Update on pea root rot in Syama Chatterton, Lethbridge Research Centre Agronomy Update January 17-18, 2017, Lethbridge, AB

Update on pea root rot in Syama Chatterton, Lethbridge Research Centre Agronomy Update January 17-18, 2017, Lethbridge, AB Update on pea root rot in 2016 Syama Chatterton, Lethbridge Research Centre Agronomy Update January 17-18, 2017, Lethbridge, AB Overview Root rot surveys in 2016 Distribution of pathogens in AB Intro to

More information

Modeling potential effects of climate change on potato late blight

Modeling potential effects of climate change on potato late blight Modeling potential effects of climate change on potato late blight Prof. Dr. Ariena van Bruggen Emerging Pathogens Institute and Plant Pathology Department, IFAS University of Florida at Gainesville In

More information

PLP 6404 Epidemiology of Plant Diseases Spring Lecture 17: Disease progress in space: dispersal and disease gradients

PLP 6404 Epidemiology of Plant Diseases Spring Lecture 17: Disease progress in space: dispersal and disease gradients PLP 6404 Epidemiology of Plant Diseases Spring 2015 Lecture 17: Disease progress in space: dispersal and disease gradients Dispersal processes Dispersal - the movement of propagative units of a pathogen

More information

Biological control of pathozone behaviour and disease dynamics of Rhizoctonia solani by Trichoderma viride

Biological control of pathozone behaviour and disease dynamics of Rhizoctonia solani by Trichoderma viride New Phytol. (1997), 136, 359-367 Biological control of pathozone behaviour and disease dynamics of Rhizoctonia solani by Trichoderma viride BYD.J. BAILEY* AND C.A. GILLIGAN Department of Plant Sciences,

More information

A closer look at pulse diseases. Barbara Ziesman Provincial Specialist, Plant Disease 2017 Regional Pulse Meetings

A closer look at pulse diseases. Barbara Ziesman Provincial Specialist, Plant Disease 2017 Regional Pulse Meetings A closer look at pulse diseases Barbara Ziesman Provincial Specialist, Plant Disease 2017 Regional Pulse Meetings Seed quality Quality can mean different things depending on whether you are talking about

More information

12/17/2014. Overview. PLP 6404 Epidemiology of Plant Diseases Spring 2015 Lecture 28: Disease forecasting. Introduction to disease forecasting

12/17/2014. Overview. PLP 6404 Epidemiology of Plant Diseases Spring 2015 Lecture 28: Disease forecasting. Introduction to disease forecasting PLP 6404 Epidemiology of Plant Diseases Spring 2015 Lecture 28: Disease forecasting Prof. Dr. Ariena van Bruggen Emerging Pathogens Institute and Plant Pathology Department, IFAS University of Florida

More information

CALIFORNIA ICEBERG LETTUCE RESEARCH PROGRAM. April 1, March 31, 2009

CALIFORNIA ICEBERG LETTUCE RESEARCH PROGRAM. April 1, March 31, 2009 CALIFORNIA ICEBERG LETTUCE RESEARCH PROGRAM April 1, 28 - March 31, 29 EPIDEMIOLOGY AND CONTROL OF LETTUCE DROP CAUSED BY SCLEROTINIA Krishna V. Subbarao Department of Plant Pathology, University of California,

More information

Biology and Ecology of Soilborne Organisms

Biology and Ecology of Soilborne Organisms Identification, Assessment and Management of Soilborne Plant Pathogens in Vegetable Production Systems Biology and Ecology of Soilborne Organisms Beth K. Gugino Department of Plant Pathology and Environmental

More information

Forest Pest Management

Forest Pest Management Forest Pest Management Report 87-12 3450 December 1987 MORTALITY OF BAREROOT COLORADO BLUE SPRUCE SEEDLINGS MONTANA STATE NURSERY, MISSOULA by R. L. James, Plant Pathologist INTRODUCTION Bareroot conifer

More information

CALIFORNIA ICEBERG LETTUCE RESEARCH PROGRAM. April 1, March 31, 2008

CALIFORNIA ICEBERG LETTUCE RESEARCH PROGRAM. April 1, March 31, 2008 CALIFORNIA ICEBERG LETTUCE RESEARCH PROGRAM April 1, 2007 - March 31, 2008 EPIDEMIOLOGY AND CONTROL OF LETTUCE DROP CAUSED BY SCLEROTINIA Krishna V. Subbarao Department of Plant Pathology, University of

More information

REPORT TO THE OREGON PROCESSED VEGETABLE COMMISSION:

REPORT TO THE OREGON PROCESSED VEGETABLE COMMISSION: REPORT TO THE OREGON PROCESSED VEGETABLE COMMISSION: Title: Impact of biological control on white mold sclerotial survival and disease severity in subsequent resistant and susceptible bean crops. Principal

More information

PLP 6404 Epidemiology of Plant Diseases Spring 2015 LAB 2 PHASES IN THE DISEASE CYCLE: GREENHOUSE AND LAB EXERCISE

PLP 6404 Epidemiology of Plant Diseases Spring 2015 LAB 2 PHASES IN THE DISEASE CYCLE: GREENHOUSE AND LAB EXERCISE PLP 6404 Epidemiology of Plant Diseases Spring 2015 LAB 2 PHASES IN THE DISEASE CYCLE: GREENHOUSE AND LAB EXERCISE "Variation in Host-Pathogen Interactions and its Effect on Epidemic Development" Purpose:

More information

Epidem16_6 Page 1. Epidem16_6 Page 2

Epidem16_6 Page 1. Epidem16_6 Page 2 Temporal analysis of epidemics: Disease progress over time Previously: Considered concept of epidemic (MHV, chapter 1) Measurement of disease intensity (chapter 2) Models for relations (response:predictor)

More information

Development of Plant Diseases Disease of a plant could simply be defined as any alteration of one or more of the ordered series of physiological

Development of Plant Diseases Disease of a plant could simply be defined as any alteration of one or more of the ordered series of physiological Development of Plant Diseases Disease of a plant could simply be defined as any alteration of one or more of the ordered series of physiological process resulting in a loss of co-ordination of the energy

More information

A (ng) Protocol. Phenol: 87.1 Kit: 37.7 SPION: Phenol: 23.8 Kit: 14.7 SPION: 6.46

A (ng) Protocol. Phenol: 87.1 Kit: 37.7 SPION: Phenol: 23.8 Kit: 14.7 SPION: 6.46 Table 1. A super paramagnetic iron oxide nanoparticle (SPION) based genomic DNA extraction from soil method was compared to a standard phenol-based method and a commercial kit. Approximately 10 second-stage

More information

Spatial analysis of epidemics: Disease gradients and patterns

Spatial analysis of epidemics: Disease gradients and patterns Spatial analysis of epidemics: Disease gradients and patterns Space.The Frontier.Finally. Epidemics are dynamic population processes in time and space We have spent a few weeks dealing exclusively with

More information

COMPARISON OF MODULES OF INTEGRATED PRACTICES WITH FARMER S PRACTICES ON FARMERS FIELD TO MANAGE AFLATOXIN IN GROUNDNUT

COMPARISON OF MODULES OF INTEGRATED PRACTICES WITH FARMER S PRACTICES ON FARMERS FIELD TO MANAGE AFLATOXIN IN GROUNDNUT COMPARISON OF MODULES OF INTEGRATED PRACTICES WITH FARMER S PRACTICES ON FARMERS FIELD TO MANAGE AFLATOXIN IN GROUNDNUT B. R. Nakrani, Assistant Research Scientist (Plant Pathology), Regional Research

More information

DISEASE MANAGEMENT STRATEGIES

DISEASE MANAGEMENT STRATEGIES DISEASE MANAGEMENT STRATEGIES Managing diseases effectively involves making the best possible decisions to reduce the risk of serious disease-related losses. The strategies upon which effective management

More information

Crown and Root Disease Management Practices for Small Grains caused by Soilborne Plant-pathogenic Fungi

Crown and Root Disease Management Practices for Small Grains caused by Soilborne Plant-pathogenic Fungi Crown and Root Disease Management Practices for Small Grains caused by Soilborne Plant-pathogenic Fungi FWAA Winter Conference - January 10, 2015 Richard Smiley Oregon State University Columbia Basin Agricultural

More information

Disease Management In Irrigated Row Crops

Disease Management In Irrigated Row Crops Disease Management In Irrigated Row Crops Melvin A. Newman, Ph.D. Professor University of Tennessee Extension Entomology and Plant Pathology Dept. Jackson, TN 6 Soybean Disease Loss Estimate for Tennessee,

More information

Estimating the delay between host infection and disease (incubation period) and assessing its significance to the epidemiology of plant diseases

Estimating the delay between host infection and disease (incubation period) and assessing its significance to the epidemiology of plant diseases Estimating the delay between host infection and disease (incubation period) and assessing its significance to the epidemiology of plant diseases Melen Leclerc, Thierry Doré, Christopher Gilligan, Philippe

More information

Organic and Sustainable Farming. 11:00-12:30 Capturing the Organic Market 2:00-3:00 Organic Pest Management 4:30-5:30 Alternative Soil Management

Organic and Sustainable Farming. 11:00-12:30 Capturing the Organic Market 2:00-3:00 Organic Pest Management 4:30-5:30 Alternative Soil Management Organic and Sustainable Farming 11:00-12:30 Capturing the Organic Market 2:00-3:00 Organic Pest Management 4:30-5:30 Alternative Soil Management The 2012 Educational Program Committee is pleased to share

More information

Pea root rot in Alberta: surveys, research and recommendations

Pea root rot in Alberta: surveys, research and recommendations Pea root rot in Alberta: surveys, research and recommendations S. Chatterton, M.W. Harding and R. Bowness Agronomy Update January 21 st, Lethbridge, AB Root rot development during late flowering Stunting,

More information

Title: Quantification of soilborne pathogens of potato using real-time PCR

Title: Quantification of soilborne pathogens of potato using real-time PCR 1 Title: Quantification of soilborne pathogens of potato using real-time PCR Principle Investigator: Neil C. Gudmestad, Department of Plant Pathology, North Dakota State University, Fargo, ND. Neil.Gudmestad@ndsu.edu

More information

QualiPlate kit for Detection of Soybean Rust. Murali Bandla EnviroLogix Inc

QualiPlate kit for Detection of Soybean Rust. Murali Bandla EnviroLogix Inc QualiPlate kit for Detection of Soybean Rust Murali Bandla EnviroLogix Inc Putting Science to the Test EnviroLogix Inc. WHAT DO WE DO? We develop, manufacture and market immunoassay test kits for the detection

More information

Onion Stunting Caused by Rhizoctonia: Management and Economic Importance in the Columbia Basin of Oregon and Washington

Onion Stunting Caused by Rhizoctonia: Management and Economic Importance in the Columbia Basin of Oregon and Washington Onion Stunting Caused by Rhizoctonia: Management and Economic Importance in the Columbia Basin of Oregon and Washington Dipak Poudyal and Lindsey du Toit, Washington State University; Tim Paulitz and Lyndon

More information

Recommended Resources: The following resources may be useful in teaching this lesson:

Recommended Resources: The following resources may be useful in teaching this lesson: Unit G: Pest Management Lesson 1: Understanding Integrated Pest Management (IPM) Student Learning Objectives: Instruction in this lesson should result in students achieving the following objectives: 1.

More information

Competition between strains of a pathogenic fungus in plant leaves

Competition between strains of a pathogenic fungus in plant leaves Competition between strains of a pathogenic fungus in plant leaves Leonard, K.J. 1, M.R. Newton 2, and L.L. Kinkel 2 1 USDA,ARS Cereal Disease Laboratory 2 Department of Plant Pathology, University of

More information

Expert views on Root Health from around the world. Dr. Melanie Goll Development Support Manager, Syngenta

Expert views on Root Health from around the world. Dr. Melanie Goll Development Support Manager, Syngenta Expert views on Root Health from around the world Dr. Melanie Goll Development Support Manager, Syngenta Content The invisible half of the plant Cause and consequence The complexity challenge Holistic

More information

TIMELY INFORMATION Agriculture & Natural Resources

TIMELY INFORMATION Agriculture & Natural Resources PLANT PATHOLOGY SERIES TIMELY INFORMATION Agriculture & Natural Resources EXTENSION PLANT PATHOLOGY, 961 S. DONAHUE DRIVE, AUBURN UNIVERSITY, AL 36849-5624 May 24, 2011 PP-698 2011 Peanut Disease Risk

More information

yeast cell virus fungal hypha (filament)

yeast cell virus fungal hypha (filament) Biology 1.3 AS 90927 Demonstrate understanding of biological ideas relating to micro-organisms Externally assessed 4 credits Copy correctly Up to 3% of a workbook Copying or scanning from ESA workbooks

More information

Diffuse symbioses: competition, coevolution, and pathogen suppression in the rhizosphere

Diffuse symbioses: competition, coevolution, and pathogen suppression in the rhizosphere Diffuse symbioses: competition, coevolution, and pathogen suppression in the rhizosphere Linda L. Kinkel Department of Plant Pathology University of Minnesota U.S. National Science Foundation-Sponsored

More information

Lecture 13 - Different methods of Nematode Control

Lecture 13 - Different methods of Nematode Control Lecture 13 - Different methods of Nematode Control Plant parasitic nematodes can be controlled by several methods. The nematode control aims to improve growth, quality and yield by keeping the nematode

More information

Organic Grain Production Resource Book OGRAIN Page 139 of 200

Organic Grain Production Resource Book OGRAIN Page 139 of 200 Organic Grain Production Resource Book OGRAIN Page 139 of 200 eorganic author: Organic Grain Production Resource Book OGRAIN Page 140 of 200 Trichoderma Pseudomonas putida Organic Grain Production Resource

More information

Late Blight SLIDE 5: Steven B. Johnson, Ph.D. UMaine Cooperative Extension Page 1

Late Blight SLIDE 5: Steven B. Johnson, Ph.D. UMaine Cooperative Extension Page 1 SLIDE 1: This is Steve Johnson, University of Maine Cooperative Extension, bringing you information on Potato Late Blight. It is possible to receive a Maine Board of Pesticides Control recertification

More information

F.A. DELA PEÑA L.U. DELA CRUZ

F.A. DELA PEÑA L.U. DELA CRUZ BIOTROPIA No. 7, 1994: 1-11 BIOLOGICAL CONTROL OF DAMPING-OFF FUNGI OF AGOHO (CASUARINA EQUISETIFOLIA L.) USING ANTAGONISTIC BACTERIA F.A. DELA PEÑA Mariano Marcos State University, Batac, Ilocos Norte

More information

Biological Control of Sheath Blight Disease of Rice by using Antagonistic Bacteria

Biological Control of Sheath Blight Disease of Rice by using Antagonistic Bacteria BCSIR Available online at www.banglajol.info Bangladesh J. Sci. Ind. Res. 45(3), 225-232, 2010 Biological Control of Sheath Blight Disease of Rice by using Antagonistic Bacteria BANGLADESH JOURNAL OF SCIENTIFIC

More information

TEST YOUR IRRIGATION WATER FOR PHYTOPHTHORA

TEST YOUR IRRIGATION WATER FOR PHYTOPHTHORA Adapted from American Nurseryman (March, 2018) TEST YOUR IRRIGATION WATER FOR PHYTOPHTHORA Phytophthora is a fungus-like organism called water mold, that can infect a wide variety of nursery plant species,

More information

REPORT TO THE OREGON PROCESSED VEGETABLE COMMISSION

REPORT TO THE OREGON PROCESSED VEGETABLE COMMISSION REPORT TO THE OREGON PROCESSED VEGETABLE COMMISSION Title: Biological control and reduced-tillage for white mold management in Willamette Valley processed snap bean production. PI: Alex Stone, Dept of

More information

The detection of Spongospora subterranea by bioassays, molecular and serological methods

The detection of Spongospora subterranea by bioassays, molecular and serological methods The detection of Spongospora subterranea by bioassays, molecular and serological methods K. Bouchek-Mechiche, D. Ruer, D. Andrivon and B. Jouan, INRA, UMR BIO3P, Domaine de la Motte, Bp35F- 35653 Le Rheu

More information

BLACKLEG RESISTANCE IN CANOLA, ITS BREAKDOWN AND LATEST STRATEGIES BEING ADOPTED IN AUSTRALIA TO MANAGE THE DISEASE.

BLACKLEG RESISTANCE IN CANOLA, ITS BREAKDOWN AND LATEST STRATEGIES BEING ADOPTED IN AUSTRALIA TO MANAGE THE DISEASE. BLACKLEG RESISTANCE IN CANOLA, ITS BREAKDOWN AND LATEST STRATEGIES BEING ADOPTED IN AUSTRALIA TO MANAGE THE DISEASE. Andrew Easton Crop Research Lead Brassicas. Pacific Seeds, Toowoomba Qld Australia.

More information

Plant Pathology. Talley Student Union 4140 Governance Chamber November 20, :00 am - 12:00 noon SPEAKERS:

Plant Pathology. Talley Student Union 4140 Governance Chamber November 20, :00 am - 12:00 noon SPEAKERS: Plant Pathology Master s Symposium Talley Student Union 4140 Governance Chamber November 20, 2015 10:00 am - 12:00 noon SPEAKERS: Emma Wallace Andrew Scruggs Megan Miller Nathan Miller Michael Cannon WELCOME

More information

Trichoderma species are known

Trichoderma species are known Research Paper : Influence of temperature and ph on antagonistic potential of Trichoderma viride in vitro International Journal of Plant Protection (October, 2010), Vol. 3 No. 2 : 165-169 Correspondence

More information

Alternative Management Tactics for Combating Soilborne Phytophthora Diseases

Alternative Management Tactics for Combating Soilborne Phytophthora Diseases Alternative Management Tactics for Combating Soilborne Phytophthora Diseases Jim Downer University of California Cooperative Extension Ventura, CA 91003 ajdowner@ucdavis.edu Avocado Root Rot Phytophthora:

More information

Mass Production of Gummy Stem Blight Spores for Resistance Screening

Mass Production of Gummy Stem Blight Spores for Resistance Screening Mass Production of Gummy Stem Blight Spores for Resistance Screening Gabriele Gusmini, Tammy L. Ellington, and Todd C. Wehner Department of Horticultural Science, North Carolina State University, Raleigh,

More information

NEW APPROACHES TO CONTROL DISEASES IN ONIONS AND POTATOES

NEW APPROACHES TO CONTROL DISEASES IN ONIONS AND POTATOES NEW APPROACHES TO CONTROL DISEASES IN ONIONS AND POTATOES Mike Thornton Parma R& E Center Potato Program of Distinction OUTLINE Disease control in onions with drip application of Fontelis Control of the

More information

Pollution of Surface Irrigation Waters by Plant Pathogenic Organisms

Pollution of Surface Irrigation Waters by Plant Pathogenic Organisms University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Papers in Plant Pathology Plant Pathology Department 8-1975 Pollution of Surface Irrigation Waters by Plant Pathogenic Organisms

More information

Biopesticides for berry crop production. Anissa Poleatewich 2016 Biocontrol Berry Day

Biopesticides for berry crop production. Anissa Poleatewich 2016 Biocontrol Berry Day Biopesticides for berry crop production Anissa Poleatewich 2016 Biocontrol Berry Day Biological control can be used to suppress many types of pest organisms Weeds APSnet Plant pathogens Insects What is

More information

Comparative Efficacy of Different Isolates of Trichoderma Spp. Against Rhizoctonia Solani, Incitant of Sheath Blight of Rice

Comparative Efficacy of Different Isolates of Trichoderma Spp. Against Rhizoctonia Solani, Incitant of Sheath Blight of Rice Comparative Efficacy of Different Isolates of Trichoderma Spp. Against Rhizoctonia Solani, Incitant of Sheath Blight of Rice 1 B. Nagendra Prasad and *M. Reddi Kumar 2 1 Department of Plant Pathology,

More information

IN VITRO INTEGRATED CONTROL OF COLLETOTRICHUM GLOEOSPORIOIDES WITH BIOLOGICAL AND CHEMICAL AGENTS

IN VITRO INTEGRATED CONTROL OF COLLETOTRICHUM GLOEOSPORIOIDES WITH BIOLOGICAL AND CHEMICAL AGENTS Sarhad J. Agric. Vol.24, No.1, 2008 IN VITRO INTEGRATED CONTROL OF COLLETOTRICHUM GLOEOSPORIOIDES WITH BIOLOGICAL AND CHEMICAL AGENTS Adil Hussain, Fazli Raziq and Hakim Khan ABSTRACT To study the effect

More information

01/08/2018. Control of Microbial Growth. Methods. Terminology. Disinfectants and Antiseptics. Three approaches. Cleaning. Chemical.

01/08/2018. Control of Microbial Growth. Methods. Terminology. Disinfectants and Antiseptics. Three approaches. Cleaning. Chemical. Control of Microbial Growth Disinfectants and Antiseptics 1 Methods 2 Three approaches Chemical Disinfectants and antiseptics Physical Heat Ultraviolet Irradiations Mechanical elimination Cleaning Filtration

More information

CALIFORNIA ICEBERG LETTUCE RESEARCH PROGRAM. April 1, March 31, 2010

CALIFORNIA ICEBERG LETTUCE RESEARCH PROGRAM. April 1, March 31, 2010 CALIFORNIA ICEBERG LETTUCE RESEARCH PROGRAM April 1, 2009 - March 31, 2010 EPIDEMIOLOGY AND CONTROL OF LETTUCE DROP CAUSED BY SCLEROTINIA Krishna V. Subbarao Department of Plant Pathology, University of

More information

NOBACTRA TOMATO FOR THE CONTROL OF BACTERIAL CANKER

NOBACTRA TOMATO FOR THE CONTROL OF BACTERIAL CANKER NOBACTRA TOMATO FOR THE CONTROL OF BACTERIAL CANKER November 1, 2016 11/9/16 1 Our Mission: To develop BREAKTHROUGH, ENVIRONMENTALLY FRIENDLY soluhons for BACTERIAL DISEASES in agriculture. 11/9/16 2 SCIENTIFIC

More information

NebGuide. Management of Phytophthora Root and Stem Rot of Soybean. Nebraska Extension. Symptoms. Environmental Conditions

NebGuide. Management of Phytophthora Root and Stem Rot of Soybean. Nebraska Extension. Symptoms. Environmental Conditions NebGuide Nebraska Extension Research-Based Information That You Can Use G1785 Index: Crops, Plant Diseases Issued December 2016 Management of Phytophthora Root and Stem Rot of Soybean Loren J. Giesler,

More information

MINIMIZING DISEASES OF PEANUT IN THE SOUTHEASTERN UNITED STATES. The 2015 Version of the Peanut Disease Risk Index (Peanut Rx)

MINIMIZING DISEASES OF PEANUT IN THE SOUTHEASTERN UNITED STATES. The 2015 Version of the Peanut Disease Risk Index (Peanut Rx) MINIMIZING DISEASES OF PEANUT IN THE SOUTHEASTERN UNITED STATES The 2015 Version of the Peanut Disease Risk Index (Peanut Rx) Robert Kemerait, Albert Culbreath, Eric Prostko, Tim Brenneman, Nathan Smith,

More information

DD 09: Criteria for Evaluating Phytosanitary Seed Treatments

DD 09: Criteria for Evaluating Phytosanitary Seed Treatments DD 09: Prepared by the members of the North American Plant Protection Organization (NAPPO) Expert Group on Seeds, comprised of subject matter experts from the National Plant Protection Organization of

More information

Field evaluation of selected formulations of Trichoderma species as seed treatment to control damping-off of cowpea caused by Macrophomina phaseolina

Field evaluation of selected formulations of Trichoderma species as seed treatment to control damping-off of cowpea caused by Macrophomina phaseolina African Journal of Biotechnology Vol. 5 (5), pp. 419-424, 1 March 2006 Available online at http://www.academicjournals.org/ajb ISSN 1684 5315 2006 Academic Journals Full Length Research Paper Field evaluation

More information

Evaluation of Onion Soil Amendment to Control White Rot

Evaluation of Onion Soil Amendment to Control White Rot Evaluation of Onion Soil Amendment to Control White Rot Jeremiah Dung Oregon State University - Central Oregon Agricultural Research Center Madras, Oregon Allium White Rot Caused by the fungus Sclerotium

More information

2011 Pennsylvania Vegetable Marketing and Research Program Pennsylvania Vegetable Growers Association Report December 7, 2011

2011 Pennsylvania Vegetable Marketing and Research Program Pennsylvania Vegetable Growers Association Report December 7, 2011 2011 Pennsylvania Vegetable Marketing and Research Program Pennsylvania Vegetable Growers Association ort December 7, 2011 Title: Extended season management of snap bean root pathogens using combinations

More information

Studies on the Compatibility of Biocontrol Agents with Certain Fungicides

Studies on the Compatibility of Biocontrol Agents with Certain Fungicides International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 3 (2017) pp. 1639-1644 Journal homepage: http://www.ijcmas.com Original Research Article https://doi.org/10.20546/ijcmas.2017.603.189

More information

Powdery scab. Research in Switzerland

Powdery scab. Research in Switzerland Powdery scab. Research in Switzerland U. Merz, Federal Institute of Technology, Institute of Plant Sciences, Plant Pathology, 8091 Zurich, Switzerland There is a long tradition of powdery scab research

More information

Why is Rhizoctonia increasing? Favorable weather Susceptible crops sown in rotations - Crops affect populations of R. solani in soil Management Rhizoc

Why is Rhizoctonia increasing? Favorable weather Susceptible crops sown in rotations - Crops affect populations of R. solani in soil Management Rhizoc RHIZOCTONIA FORUM: EPIDEMIOLOGY AND ROTATION CROPS Carol Windels University of Minnesota NW Research & Outreach Center Crookston, Minnesota Moderator: Gary Franc Why is Rhizoctonia increasing? Favorable

More information

Bayesian statistics for infection experiments

Bayesian statistics for infection experiments 11 Bayesian statistics for infection experiments Lourens Heres # and Bas Engel ## Abstract To intervene cycles of food-borne pathogens in poultry new intervention methods need to be tested for their effectiveness.

More information

MINIMIZING DISEASES OF PEANUT IN THE SOUTHEASTERN UNITED STATES. The 2016 Version of the Peanut Disease Risk Index

MINIMIZING DISEASES OF PEANUT IN THE SOUTHEASTERN UNITED STATES. The 2016 Version of the Peanut Disease Risk Index The Spotted Wilt Index and the Peanut Fungal Disease Risk Index were successfully combined in 2005 to produce the Peanut Disease Risk Index for peanut producers in thesoutheastern MINIMIZING DISEASES OF

More information

DESIGN AND INTERPRETATION OF SEED HEALTH ASSAYS. Summary

DESIGN AND INTERPRETATION OF SEED HEALTH ASSAYS. Summary Proceedings of the First ISTA PDC Symposium on Seed Health Testing, Ottawa, Canada, August 1993 DESIGN AND INTERPRETATION OF SEED HEALTH ASSAYS 1 Roberts, S.J., Phelps, K., Taylor, J.D., 2 Ridout, M.S.

More information

CHAPTER 24. Immunology

CHAPTER 24. Immunology CHAPTER 24 Diagnostic i Microbiology and Immunology Growth-Dependent Diagnostic Methods Isolation of Pathogens from Clinical Specimens Proper sampling and culture of a suspected pathogen is the most reliable

More information

Fusarium Head Blight

Fusarium Head Blight Fusarium Head Blight Amendment Act, 2014: Bill 201 Vikram Bisht, Ph.D. Plant Pathologist MB Agriculture Food & Rural Development vikram.bisht@gov.mb.ca FHB Impacts the Bottom Line Loss of yield Reduced

More information

This presentation is available at Borges, University of Wisconsin Agronomy

This presentation is available at   Borges, University of Wisconsin Agronomy SOYBEAN YIELD IS A COMPLEX SERIES OF INTERACTIONS Management Soil type Fertility Herbicide Weeds YIELD Weather Insects Variety Diseases SCN WISCONSIN SOYBEAN PRODUCTION KEYS TO SUCCESS Fertilize and lime

More information

How do Canadian growers manage blackleg, club root and sclerotinia in canola? Dr. Lone Buchwaldt

How do Canadian growers manage blackleg, club root and sclerotinia in canola? Dr. Lone Buchwaldt How do Canadian growers manage blackleg, club root and sclerotinia in canola? Dr. Lone Buchwaldt Canada has 13 Provinces/Territories and 20 federal research centres for agriculture Lone Buchwaldt, Plant

More information

STATUS OF APHANOMYCES ROOT ROT IN WISCONSIN. C.R. Grau 1. Introduction

STATUS OF APHANOMYCES ROOT ROT IN WISCONSIN. C.R. Grau 1. Introduction STATUS OF APHANOMYCES ROOT ROT IN WISCONSIN C.R. Grau 1 Introduction Alfalfa is the primary forage crop in Wisconsin and is a key element in the state s dairy industry. The yield of new varieties is greater

More information

Instytut Badawczy Lesnictwa (IBL) Forestry Research Institute Warsaw, 1995

Instytut Badawczy Lesnictwa (IBL) Forestry Research Institute Warsaw, 1995 EFFECTIVENESS OF FOLPAN 80 WG, SINCOCIN AND TRICHODEX WP 25 IN SUPPRESSING THE DEVELOPMENT OF FUNGUS DISEASES IN FORESTRY NURSERIES Instytut Badawczy Lesnictwa (IBL) Forestry Research Institute Warsaw,

More information

Validating methods and organizing and analyzing results of interlaboratory comparative tests (CT)

Validating methods and organizing and analyzing results of interlaboratory comparative tests (CT) INTERNATIONAL SEED TESTING ASSOCIATION (ISTA) Secretariat, Zürichstrasse 50, 8303 Bassersdorf, CH-Switzerland Phone: +41-44-838 60 00, Fax: +41-44-838 60 01, Email: ista.office@ista.ch, http://www.seedtest.org

More information

Antagonistic activity of selected fungi occurring in the soil after root chicory cultivation

Antagonistic activity of selected fungi occurring in the soil after root chicory cultivation Antagonistic activity of selected fungi occurring in the soil after root chicory cultivation E. Patkowska 1, M. Błażewicz-Woźniak 2, M. Konopiński 2 1 Department of Plant Pathology and Mycology, University

More information

Project Title: Spinach Breeding and Genetics

Project Title: Spinach Breeding and Genetics Project Title: Spinach Breeding and Genetics Project Investigator: Beiquan Mou Research Geneticist Agricultural Research Service U.S. Dept. of Agriculture 1636 E. Alisal Street Salinas, CA 93905 Office

More information

potato dextrose agar (PDA) at 4 C for have pronounced impacts on the population of subsequent use. all types of soil micro-organisms including

potato dextrose agar (PDA) at 4 C for have pronounced impacts on the population of subsequent use. all types of soil micro-organisms including The Journal of Plant Protection Sciences, 3() : 3-3, June, Population proliferation and spread of Trichoderma spp. in soil under two different delivery systems Sitansu Pan and Amrita Das Department of

More information

AN UPDATE ON SPOT FORM NET BLOTCH (SFNB) IN THE NORTHERN REGION

AN UPDATE ON SPOT FORM NET BLOTCH (SFNB) IN THE NORTHERN REGION Consultant s Corner* AN UPDATE ON SPOT FORM NET BLOTCH (SFNB) IN THE NORTHERN REGION 1. The research view - Greg Platz QDPI&F Hermitage Spot form of net blotch (Pyrenophora teres f. maculata) is the most

More information

Production Systems Plants Theme Advisory Group. Research Highlights Plant Pathology

Production Systems Plants Theme Advisory Group. Research Highlights Plant Pathology Production Systems Plants Theme Advisory Group Research Highlights Plant Pathology Plant Protection Pest management Biology Diagnosis Production Efficiency Environmental Ecosystems Impact Product Diversification

More information

Integrated Disease Management for Vegetable Crops in Florida 1

Integrated Disease Management for Vegetable Crops in Florida 1 PP-193 Integrated Disease Management for Vegetable Crops in Florida 1 Tim Momol, Jim Marois, Ken Pernezny and Steve Olson 2 Introduction A successful disease control program depends on a crop production

More information

Disease in this heat? John Damicone, Extension Plant Pathologist

Disease in this heat? John Damicone, Extension Plant Pathologist Entomology and Plant Pathology, Oklahoma State University 127 Noble Research Center, Stillwater, OK74078 405.744.5527 Vol. 10, No. 18 http://entoplp.okstate.edu/pddl/ Aug 4, 2011 Disease in this heat?

More information

Nematodes in seed potato production: cuidado!

Nematodes in seed potato production: cuidado! Nematodes in seed potato production: cuidado! Nicole Viaene 5 September 2013 visit Chilean potato group and Belgapom Institute for Agricultural and Fisheries Research Plant Sciences Unit www.ilvo.vlaanderen.be

More information

Non-fumigant options for replant disease/nematode management

Non-fumigant options for replant disease/nematode management Non-fumigant options for replant disease/nematode management OSU Replant Discussion March 17, 2017 Tom Forge Replant management for cherry Soil factors causing poor establishment of replanted fields/orchards

More information

Diseases of seeds, seedlings and roots: Aphanomyces root rot

Diseases of seeds, seedlings and roots: Aphanomyces root rot Diseases of seeds, seedlings and roots: Aphanomyces root rot Diseases of seeds, seedlings and roots: Aphanomyces root rot Photos: Lyndon Porter, USDA-ARS Aphanomyces Symptoms: Initial root rot symptoms:

More information

Crop Protection Research Institute

Crop Protection Research Institute Crop Protection Research Institute The Importance of Soil Vegetables Fumigation: Michigan CropLife Foundation 1156 15th Street, NW #400 Washington, DC 20005 Phone 202-296-1585 www.croplifefoundation.org

More information

RHIZOCTONIA ROOT ROT OF SUGARBEET AS AFFECTED BY RATE AND NITROGEN FERTILIZER CARRIER*

RHIZOCTONIA ROOT ROT OF SUGARBEET AS AFFECTED BY RATE AND NITROGEN FERTILIZER CARRIER* RHIZOCTONIA ROOT ROT OF SUGARBEET AS AFFECTED BY RATE AND NITROGEN FERTILIZER CARRIER* R. J. Hecker and E. G. Ruppel Received for Publication June 30, 1980 INTRODUCTION Sugar beet (Beta vulgaris L.) crop

More information

Optimizing Cereal Productivity using Seed Treatments & Fungicides

Optimizing Cereal Productivity using Seed Treatments & Fungicides Optimizing Cereal Productivity using Seed Treatments & Fungicides Wheat U 2017 Paula Halabicki Technical Market Manager High Yields Are Not Accidents Potential Crop Yield Minimum or Limiting Factor Fertility

More information

Disease Management in Soybeans. Sam Markell, Ph.D. Extension Plant Pathologist

Disease Management in Soybeans. Sam Markell, Ph.D. Extension Plant Pathologist Disease Management in Soybeans Sam Markell, Ph.D. Extension Plant Pathologist Diseases of Soybean Leaves Hardly enough to think about Stems Enough to think about Roots Enough to actively manage Root Rots

More information

MANAGEMENT OF BROWN SPOT DISEASE OF RICE BY USING SAFER FUNGICIDES AND SOME BIOAGENTS

MANAGEMENT OF BROWN SPOT DISEASE OF RICE BY USING SAFER FUNGICIDES AND SOME BIOAGENTS NSave Nature to Survive 9(1): 437-441, 2014 (Supplement on Plant Pathology) www.thebioscan.in MANAGEMENT OF BROWN SPOT DISEASE OF RICE BY USING SAFER FUNGICIDES AND SOME BIOAGENTS D. SARKAR 1 *, R. MANDAL

More information

For in vitro Veterinary Diagnostics only. Kylt Brachyspira spp. Real-Time PCR Detection.

For in vitro Veterinary Diagnostics only. Kylt Brachyspira spp. Real-Time PCR Detection. For in vitro Veterinary Diagnostics only. Kylt Brachyspira spp. Real-Time PCR Detection www.kylt.eu DIRECTION FOR USE Kylt Brachyspira spp. Real-Time PCR Detection A. General Kylt Brachyspira spp. products

More information

Decision support scheme conducted for Gibberella circinata

Decision support scheme conducted for Gibberella circinata Decision support scheme conducted for Gibberella circinata Part A: Key information and selection of measures A1. Basic information A1.1 - Pest common name Pitch canker disease A1.2 - Scientific name Teleomorph:

More information

Journal of Plant Pathology (2007), 89 (2), Edizioni ETS Pisa,

Journal of Plant Pathology (2007), 89 (2), Edizioni ETS Pisa, Journal of Plant Pathology (2007), 89 (2), 179-183 Edizioni ETS Pisa, 2007 179 SCREENING OF BACILLUS ISOLATES FOR POTENTIAL BIOCONTROL OF THE WILT DISEASE COMPLEX OF PIGEON PEA (CAJANUS CAJAN) UNDER GREENHOUSE

More information

Biological Control of Plant-parasitic Nematodes, 2nd Edition

Biological Control of Plant-parasitic Nematodes, 2nd Edition Biological Control of Plant-parasitic Nematodes, 2nd Edition Soil Ecosystem Management in Sustainable Agriculture Graham R. Stirling Biological Crop Protection Pty Ltd, Brisbane, Australia Foreword Preface

More information

Diseases of Soybean: Sudden Death Syndrome

Diseases of Soybean: Sudden Death Syndrome Purdue e-pubs Historical Documents of the Purdue Cooperative Extension Service Department of Agricultural Communication 3-7-2016 Diseases of Soybean: Sudden Death Syndrome Andreas Westphal Lijuan Xing

More information

Blackspot Survival in Soil and Stubble and Aerial Dissemination through the Season

Blackspot Survival in Soil and Stubble and Aerial Dissemination through the Season Blackspot Survival in Soil and Stubble and Aerial Dissemination through the Season D.M. Peck 1, G.K.McDonald 1 and J.A. Davidson 2 1 Department of Plant Science, Adelaide University, Glen Osmond SA. 2

More information