U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Crop Production and Pest Control Research: West Lafayette, IN
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Midwest Area West Lafayette, Indiana Crop Production and Pest Control Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications
- Small Grains Viral Disease Laboratory
- Corn and Sorghum Fungal Disease Laboratory
- Host Plant Resistance to Insects Laboratory
- Wheat/Hessian fly Interactions Laboratory
- Small Grains Fungal Disease Laboratory
- Soybean Quality Improvement Laboratory
- Uniform Soybean Tests, Northern Region

Title:   Author  item
                                            Goodwin, Stephen

                                                         - *Steve*
  Submitted to: International Agronomy Congress Abstracts
                                    Publication Type: Abstract Only
                                    Publication Acceptance Date: 6/9/1999
                                    Publication  Date: N/A
                                    Citation: N/AInterpretive Summary:
                                Technical Abstract: Late blight of potato and tomato, caused by Phytophthora infestans, was effectively controlled for decades in most developed countries by careful crop sanitation and judicious use of fungicides.  This changed during the mid 1980s in Europe and the early 1990s in the United States and Canada due to changes in the pathogen populations.  New populations of the pathogen  were resistant to fungicide, were more virulent, and were much more aggressive than the previous populations.  Analyses with molecular markers revealed that the new populations rapidly replaced the populations that occurred previously, usually within 2-4 years.  Migrations into the United States and Canada probably occurred by movement of infected tomato fruits from coastal production zones in northwestern Mexico.  The US-8 genotype was first detected in New York during 1992 and in the seed producing regions of Maine by 1993.  During 1994-1996 this genotype spread throughout tthe potato-producing regions of the United States and Canada, where it is still the predominating genotype.  There are now two likely outcomes in the United States and Canada: the development of sexually reproducing populations; or a gradual turnover of clonal genotypes.  Analyses of populations in northwestern Mexico have revealed a gradual turnover of clones from year to year.  These migrations have serious ramifications for plant health and quarantine operations.  The initial migrations probably occurred on tomato fruits, which were not screened for late blight.  The new genotypes moved rapidly because they were resistant to fungicide and were more aggressive than the previous genotypes.  This highlights the importance of preventing pathogen migrations and of the use of molecular markers for detection and tracking of new genotypes.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov