Source: RUTGERS, THE STATE UNIVERSITY OF NEW JERSEY submitted to
MANAGEMENT OF PHYTOPHTHORA BLIGHT ON PEPPERS AND CUCURBITS IN NEW JERSEY
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0188628
Grant No.
(N/A)
Project No.
NJ12103
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
May 1, 2001
Project End Date
Sep 30, 2006
Grant Year
(N/A)
Project Director
Oudemans, P.
Recipient Organization
RUTGERS, THE STATE UNIVERSITY OF NEW JERSEY
3 RUTGERS PLZA
NEW BRUNSWICK,NJ 08901-8559
Performing Department
PLANT BIOLOGY & PATHOLOGY
Non Technical Summary
Phytophthora blight of peppers and cucurbits is the most prevalent and destructive disease in New Jersey. Recently, fungicide resistant strains of the pathogen have been found in the state, which has resulted in outbreaks of the disease. The purpose of this research project is to document the extent and specific location of fungicide resistance within the stte, and to determine new control measures including varietal resistance, biological control agents and fungicides.
Animal Health Component
(N/A)
Research Effort Categories
Basic
10%
Applied
90%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2121429116050%
2121461116050%
Knowledge Area
212 - Pathogens and Nematodes Affecting Plants;

Subject Of Investigation
1461 - Peppers; 1429 - Cucurbits, other;

Field Of Science
1160 - Pathology;
Goals / Objectives
1. Determine the level of sensitivity of New Jersey isolate of P. capsici to the fungicide mefenoxam. 2. Determine the proper timing and concentration of mefenoxam that is needed to maintain control of P. capsici in peppers and cucurbits. 3. Utilize Global Positioning Systems (GPS), Geographic Information System s(GIS), and Remote Sensing (RS) to track mefenoxam-sensitive and insensitive populations in New Jersey fields. 4. Evaluate biological and chemical control measures for control of Phytophthora blight on peppers and cucurbits. 5. Evaluate new varieties of peppers and cucurbits for resistance to P. capsici.
Project Methods
Pepper and cucurbit plants exhibiting symptoms of PHythophthora blight will be collected following a field specific grid pattern. Isolates of P. capsici will be obtained from infected plants. Single zoospore isolates will be produced from each sample. In vitro response to mefenoxam will be determined on V8 agar plates amended with 0 and 100 ppm of mefenoxam. In vivo response to mefenoxam will be determined in the greenhouse with pepper plants produced in 4-inch diameter pots filled with soilless mix. All parameters measured will be recorded for each isolate and GPS maps will be made for each parameter based on the location of isolates in the field of collection. Field maps will be evaluated for distribution of mefenoxam insensitive isolates to determine if it is possible not to plant portions of fields due to the presence of mefenoxam insensitive isolates. Field experiments will be conducted to evaluate the timing of mefenoxam for efficacy in controlling Phytophthora blight of peppers. Fungal and bacterial antagonists of P. capsici will be evaluated in the field for efficacy in managing Phytophthora blight of peppers and cucurbits. New fungicides will be evaluated under field conditions for efficacy in controlling the crown rot and aerial phase of Phytophthora peppers and cucurbits. Pepper and cucurbit varieties possessing resistance to P. capsici will be evaluated in fields infested with the pathogen.

Progress 05/01/01 to 09/30/06

Outputs
Phytophthora capsici has been collected from several locations within New Jersey's pepper growing regions and populations have been geospatially referenced using GPS equipment. P. capsici populations have been assayed for in vitro sensitivity to the fungicide mefenoxam. Maps have been created to investigate the relationship between mefenoxam sensitivity and the location of each population including the influence of natural water sources such as rivers and streams. Mefanoxam resistance was found in several populations and isolates with virulence to a previously resistant cultivar (Paladin) were found at one location. Research on this disease will be continued with a new Principle Investigator.

Impacts
Knowledge of interactions between natural water sources and P. capsici populations would aid in developing management programs for specific locations. Areas with predominately insensitive populations of P.capsici must be managed quite differently than areas possessing populations that may be adequately controlled through use of mefenoxam.

Publications

  • No publications reported this period


Progress 01/01/04 to 12/31/04

Outputs
Phytophthora capsici has been collected from several locations within New Jersey's pepper growing regions and populations have been geospatially referenced using GPS equipment. P. capsici populations have been assayed for in vitro sensitivity to the fungicide mefenoxam. Maps have been created to investigate the relationship between mefenoxam sensitivity and the location of each population including the influence of natural water sources such as rivers and streams. This may provide insight into population dispersal and/or isolation and would be key to managing Phytophthora blight for specific locations (i.e. watersheds, water management areas, farms).

Impacts
Knowledge of interactions between natural water sources and P. capsici populations would aid in developing management programs for specific locations. Areas with predominately insensitive populations of P.capsici must be managed quite differently than areas possessing populations that may be adequately controlled through use of mefenoxam.

Publications

  • No publications reported this period


Progress 01/01/03 to 12/31/03

Outputs
Pepper variety trials were conducted to screen for resistance to crown rot caused by Phytophthora capsici. The trials were conducted at two locations in southern New Jersey. A total of eighteen varieties were screened, including several numbered (not yet released) varieties. The standard variety for resistance is "Paladin" and five of the numbered varieties performed similarly to Paladin. All of the remaining varieties (three named and nine numbered varieties) were susceptible to Phytophthora crown rot in this test. Two fungicide trials and one biological control trial were conducted. The first fungicide trial was aimed at the foliar phase of the disease and the second fungicide trial was aimed at the crown rot phase. For the foliar test, two fungicides (Ranman and Ridomil Gold Copper) used in rotation were most effective for controlling the disease. For the crown rot phase the best treatments both included two applications of Ridomil Gold as a drip treatment followed by 1) three foliar applications of Maneb plus Acrobat or 2) foliar applications of RAREC0307 (an experimental designation) in alternation with Ridomil Gold Copper (three applications total). For the biocontrol test, treatments were incorporated at the time of transplant. Two treatments were marginally successful. Both were commercially produced (B/Z and JRM both of which are produced by Agridynamics) and may have potential for commercialization.

Impacts
New varieites and fungicide use programs are essential components of the vegetable growers farming program. The results obtained for 2003 provide the necessary information for immediate (2004 growing season) use.

Publications

  • No publications reported this period


Progress 01/01/02 to 12/31/02

Outputs
A total of 603 Phytophthora capsici isolates were collected from infected pepper plants obtained in 13 fields in 4 southern New Jersey counties during the summer of 2002. All locations where infected plants were collected were recorded using global positioning systems. A sample of the isolates (144) were grown on mefenoxam amended clarified V8 agar to determine sensitivity to the fungicide. Sensitivity classes were as follows: sensitive = less than 30 % growth of unamended control at 100 ppm mefenoxam concentration; intermediate= greater than 30% growth of unamended control at 5 ppm mefenoxam concentration but less than 90% growth of the control at 100 ppm mefenoxam concentration; and insensitive= greater than 90% growth of unamended control at 100 ppm mefenoxam concentration. Of the isolates sampled 19% were sensitive to mefenoxam, 70% expressed intermediate sensitivity and 11% were insensitive to mefenoxam. Compatibility typing was performed on 97 isolates, and 46% were the A1 mating type and 54% were the A2 mating type. Bell pepper varieties were evaluated in P. capsici infested fields in southern New Jersey. `Paladin' provided excellent control of the crown rot phase of Phytophthora blight and possesses commercially acceptable horticultural characteristics.

Impacts
Characterization of the population of Phytophthora capsici enables growers to determine the feasibility of utilizing mefenoxam in a disease management program for Phytophthora blight of peppers. Fields with a population of P. capsici that is sensitive to mefenoxam can be treated with mefenoxam for control of the pathogen; however, fields with a population of P. capsici that is insensitve to mefenoxam should not be treated with mefenoxam due to lack of control provided by the fungicide. Future research anticipated in this project is designed to determine the feasibility of utilizing mefenoxam for managing intermediately sensitive populations of P. capsici to mefenoxam. Growers are encouraged to produce the variety, `Paladin' in P. capsici infested fields in order to produce an effective yield.

Publications

  • Fogg, M.L. and S.A. Johnston. 2002. Evaluation of mefenoxam application methods and timing intervals for control of Phytophthora blight of pepper. Phytopathology 92:S143.
  • Johnston, S.A., M.L. Fogg, W.L. Kline, and S.A. Garrison. 2002. Evaluation of varietal resistance for control of Phytophthora blight of peppers. Phytopathology 92:S144.
  • Johnston, S.A. W.L. Kline, M.L. Fogg and M.D. Zimmerman. 2002. Varietal resistance evaluation for control of Phytophthora blight of pepper. Phytopathology 92:S40.


Progress 01/01/01 to 12/31/01

Outputs
CRIS progress report for CY 2001 (Jan-Dec 2001) Project: #11103 Management of Phytophthora blight on pepper and cucurbits in NJ. Field experiments were conducted to evaluate various management measures for the control of Phytophthora blight on peppers and summer squash. In bare ground culture in Phytophthora capsici-infested soil, the cultivar, `Paladin' had significantly less plants infected with Phytophthora blight than the susceptible grower standard cultivar, `Camelot'. Whereas, under polyethylene mulch/drip irrigation culture in P. capsici-infested soil, both the cultivars, `Paladin' and `Aristotle' had significantly less plants infected with Phytophthora blight than the susceptible grower standard cultivar, `Camelot'. Cultivars, `Paladin' and `Aristotle', both exhibited excellent horticultural characteristics (fruit quality and marketable yield) in a separate field experiment in non-P. capsici-infested soil. In experiments designed to evaluate biological control agents and new fungicides for management of Phytophthora blight, none of the experimental treatments provided control of the disease. In an experiment to evaluate the method of application of mefenoxam for the control of Phytophthora blight of peppers, mefenoxam provided significantly longer control of blight compared to the untreated check when applied as a drench as opposed to being injected via drip irrigation early in the season; whereas, later in the season, drip injected treatments provided longer control of blight than drench treatments.

Impacts
(N/A)

Publications

  • No publications reported this period