scholarly journals Resistance of Nineteen Major Caladium Commercial Cultivars to Pythium Root Rot

EDIS ◽  
1969 ◽  
Vol 2005 (3) ◽  
Author(s):  
Zhanao Deng ◽  
Brent K. Harbaugh ◽  
Richard O. Kelly ◽  
Teresa Seijo ◽  
Robert J. McGovern
Keyword(s):  
Root Rot ◽  
Integrated Management ◽  
Ornamental Plants ◽  
Control Measures ◽  
Publication Date ◽  
Aesthetic Value ◽  
Resistance Level ◽  
University Of Florida ◽  
Pythium Root Rot ◽  
Commercial Cultivars

Caladiums (Caladium xhortulanum) are popular ornamental plants widely grown for their bright colorful leaves. Pythium root rot, caused by P. myriotylum, is one of the few soil-borne diseases in caladium that can dramatically reduce plant growth, aesthetic value, and tuber yield. Identification and use of disease-resistant cultivars has proven to be an important and economically viable strategy for integrated management of major diseases in crops and for reducing the use of pesticides. This strategy will be particularly useful for caladiums in the landscape and home gardens, because in such cases choices of root rot control measures are limited. However, information on the resistance level of commercial caladium cultivars has been lacking. This document is ENH996, one of a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date December 2, 2004.  ENH996/EP251: Resistance of Nineteen Major Caladium Commercial Cultivars to Pythium Root Rot (ufl.edu)

scholarly journals Screening for Resistance to Pythium Root Rot among Twenty-three Caladium Cultivars

EDIS ◽  
2019 ◽  
Vol 2005 (11) ◽  
Author(s):  
Zhanao Deng ◽  
Brent K. Harbaugh ◽  
Rick O. Kelly ◽  
Teresa Seijo ◽  
Robert J. McGovern
Keyword(s):  
Root Rot ◽  
Integrated Management ◽  
Cooperative Extension Service ◽  
Publication Date ◽  
University Of Florida ◽  
Resistant Cultivars ◽  
Evaluation Procedures ◽  
Pythium Root Rot ◽  
Commercial Cultivars ◽  
Screening For Resistance

Pythium root rot, caused by Pythium myriotylum (Ridings and Hartman, 1976), is a very damaging disease to caladium plants (Caladium x hortulanum). Use of disease-resistant cultivars has been an effective and economically viable strategy for integrated management of major diseases in numerous crops. This strategy could be used to control pythium root rot in caladium if resistant cultivars could be identified or developed. In an evaluation of 19 major commercial cultivars, 'Candidum', 'Candidum Jr.', 'Frieda Hemple', and 'White Christmas' were found to have a moderate level of resistance to Pythium. To find more resistant cultivars, twenty-three additional commercial cultivars were screened using the same Pythium isolates, inoculation and evaluation procedures as described earlier (Deng et al. 2004). This document is ENH1008, one of a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date September 27, 2005. ENH1008/EP259: Screening for Resistance to Pythium Root Rot among Twenty-three Caladium Cultivars (ufl.edu)

scholarly journals Screening for Resistance to Pythium Root Rot among Twenty-three Caladium Cultivars

2005 ◽  
Vol 15 (3) ◽  
pp. 631-634 ◽  
Author(s):  
Zhanao Deng ◽  
Brent K. Harbaugh ◽  
Rick O. Kelly ◽  
Teresa Seijo ◽  
Robert J. McGovern
Keyword(s):  
Root Rot ◽  
Tuber Yield ◽  
Sources Of Resistance ◽  
Aesthetic Value ◽  
Pythium Root Rot ◽  
Landscape Plants ◽  
Tuber Production ◽  
Commercial Cultivars ◽  
Loss Severity ◽  
Pot Plant

Caladiums (Caladium ×hortulanum) are widely grown as pot or landscape plants for their attractive leaves. Pythium root rot (Pythium myriotylum) is one of the most damaging diseases in caladium, severely reducing plant growth, aesthetic value, and tuber yield. Twenty-three commercial cultivars were inoculated with three aggressive isolates of P. myriotylum and evaluated for their resistance to root rot. Three cultivars, `Apple Blossom', `Blizzard', and `Etta Moore', were found to have a moderate level of resistance (partial resistance) to pythium root rot. The rest of these cultivars were susceptible or highly susceptible to Pythium infection, losing up to 94% of their root tissue to rotting within 10 days after inoculation. Data indicated a linear relationship between root rot severity and leaf loss severity on Pythium-inoculated plants and highlight the importance of controlling pythium root rot in caladium pot plant and tuber production. Comparison of some recent releases with their parents for pythium root rot resistance suggests the potential of developing new resistant caladium cultivars using the identified sources of resistance.

scholarly journals Pythium Root Rot Resistance in Commercial Caladium Cultivars

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 549-552 ◽  
Author(s):  
Zhanao Deng ◽  
Brent K. Harbaugh ◽  
Rick O. Kelly ◽  
Teresa Seijo ◽  
Robert J. McGovern
Keyword(s):  
Root Rot ◽  
Tuber Yield ◽  
Integrated Control ◽  
Ornamental Plants ◽  
Aesthetic Value ◽  
Pythium Root Rot ◽  
Yield Information ◽  
Loss Severity ◽  
Highly Virulent ◽  
Potential Use

Caladiums (Caladium ×hortulanum) are popular ornamental plants widely grown for their bright colorful leaves. Pythium root rot, caused by Pythium myriotylum, is one of the few soil-borne diseases in caladium that dramatically reduces plant growth, aesthetic value, and tuber yield. Information on the reaction of caladium cultivars to P. myriotylum is not available, but would be valuable for integrated control of this disease and for breeding new resistant cultivars. Three Pythium isolates obtained from decaying roots of plants collected from a field production site and two greenhouses were evaluated for pathogenicity and potential use in experiments to screen commercial caladium cultivars for resistance. All three isolates were found to be highly virulent; they were able to cause obvious root rotting within 3 to 5 days and severe root rotting and leaf losses on susceptible cultivars within 10 days after inoculation. Nineteen major commercial cultivars were evaluated for their resistance to these isolates. Fifteen of the cultivars were susceptible or highly susceptible to Pythium infection. Four widely grown cultivars, `Candidum', `Candidum Jr.', `Frieda Hemple', and `White Christmas', were found to have a moderate level of resistance (partial resistance) to pythium root rot. Pythium infection also caused leaf discoloration, epinasty, wilting, and collapse. Regression analyses revealed a linear relationship between the root rot and leaf loss severity on Pythium-inoculated plants.

scholarly journals Angular Leaf Spot: A Bacterial Disease in Strawberries in Florida

EDIS ◽  
1969 ◽  
Vol 2005 (1) ◽  
Author(s):  
Natalia A. Peres ◽  
Silvia I. Rondon ◽  
James F. Price ◽  
Daniel J. Cantliffe
Keyword(s):  
Leaf Spot ◽  
Gray Mold ◽  
Angular Leaf Spot ◽  
Publication Date ◽  
Bacterial Disease ◽  
University Of Florida ◽  
Pythium Root Rot ◽  
Xanthomonas Fragariae ◽  
Rapid Spread ◽  
Sphaerotheca Macularis

Angular Leaf Spot (ALS) is a bacterial disease caused by Xanthomonas fragariae Kennedy & King, a pathogen highly specific to wild and cultivated strawberry, Fragaria x ananassa Duchesne (Legard et al. 2003). ALS is an important disease on winter strawberry production worldwide. In the U.S., it ranks 6th in economic importance after gray mold (Botrytis cinerea L.), verticillium wilt (Verticillium alboatrum Reinke & Berth), powdery mildew (Sphaerotheca macularis L.), anthracnose (Colletotrichum spp.), and pythium root rot (Pythium spp.) (Sorensen et al. 1997). The rapid spread of ALS is influenced by the increasing rate of interchange of plant material. This is document PP-199, a publication of the Plant Pathology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: June 2004. PP-199/PP120: Angular Leaf Spot of Strawberries (ufl.edu)

scholarly journals Mefenoxam Sensitivity, Aggressiveness, and Identification of Pythium Species Causing Root Rot on Floriculture Crops in North Carolina

Plant Disease ◽  
2015 ◽  
Vol 99 (11) ◽  
pp. 1550-1558 ◽  
Author(s):  
E. C. Lookabaugh ◽  
K. L. Ivors ◽  
B. B. Shew
Keyword(s):  
North Carolina ◽  
Host Species ◽  
Root Rot ◽  
Internal Transcribed Spacer ◽  
Ornamental Plants ◽  
Pythium Species ◽  
Selective Media ◽  
Microtiter Plates ◽  
Pythium Root Rot

Herbaceous ornamental plants exhibiting symptoms of Pythium root rot were collected from 26 greenhouses in 21 counties in North Carolina (NC) from 2010 to 2012. Plant symptoms ranged from mild stunting to severe wilting, root rot, and death. Roots were plated on selective media, and 356 isolates of Pythium were recovered from 34 host species. Selected isolates were identified by sequencing of the internal transcribed spacer (ITS) rDNA gene region. Seventeen Pythium species were identified, with P. aphanidermatum, P. irregulare, and P. myriotylum comprising 75% of the 320 isolates sequenced. Twelve of the 26 greenhouses had more than one species present. Mefenoxam sensitivity was tested in vitro by growing isolates in wells of microtiter plates containing clarified V8 agar amended with 100 µg a.i./ml mefenoxam. Colonization was scored after 24 to 48 h using a scale of 0 (no growth) to 5 (entire well colonized). Fifty-two percent of the isolates were resistant to mefenoxam (mean score ≥4). All 32 isolates of P. myriotylum were sensitive, whereas sensitivity varied among isolates of P. aphanidermatum and P. irregulare. Resistant and sensitive isolates of the same species were found within the same greenhouses. The aggressiveness of P. aphanidermatum and P. irregulare isolates was evaluated on poinsettia, Gerbera daisy, and petunia. P. aphanidermatum was more aggressive than P. irregulare on poinsettia and petunia; symptoms were mild and no differences in aggressiveness were observed on Gerbera daisy. Sensitivity to mefenoxam was not related to aggressiveness.

scholarly journals Professional Disease Management Guide for Ornamental Plants

EDIS ◽  
1969 ◽  
Vol 2004 (15) ◽  
Author(s):  
S. D. Bledsoe ◽  
Phil F. Harmon ◽  
Robert J. McGovern
Keyword(s):  
Disease Management ◽  
Chemical Control ◽  
Ornamental Plants ◽  
Cooperative Extension Service ◽  
Cultural Control ◽  
Extension Service ◽  
Publication Date ◽  
Original Publication ◽  
University Of Florida ◽  
Control Operators

This publication is intended to be used by growers, landscape professionals, and other pest control operators as a reference for managing diseases of ornamental plants. Management tactics are outlined under the following key components of an IPM program: prevention, cultural control, scouting, physical control, biological control, and chemical control. Tables 1 - 4 contain important information on commercial products currently available for the management of diseases in ornamental plants. In addition, a list of useful websites and references is provided at the end of this document to supplement the information provided herein. This document is PP202, one of a series of the Plant Pathology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date October 2004.  PP-202/PP123: Professional Disease Management Guide for Ornamental Plants (ufl.edu)

scholarly journals Professional Applicator's Guide to Herbicides for Melaleuca Control

EDIS ◽  
2019 ◽  
Vol 2005 (15) ◽  
Author(s):  
Kenneth A. Langeland ◽  
Michael J. Meisenburg
Keyword(s):  
Integrated Management ◽  
Cooperative Extension Service ◽  
Extension Service ◽  
Publication Date ◽  
Melaleuca Quinquenervia ◽  
Original Publication ◽  
University Of Florida ◽  
Spray Solution ◽  
Application Methods ◽  
Cut Stump

Herbicides are used for integrated management of melaleuca (Melaleuca quinquenervia) trees to kill existing trees. Products with the herbicide active ingredients glyphosate, imazapyr, triclopyr, and hexazinone are used depending on the application method and other factors, including presence of non-target vegetation in the application area. Four application methods, foliar, frill-and-girdle, cut stump, and basal (applied to the soil) are used depending on extent of the population and other factors. Helicopter, truck, or all terrain vehicle (atv)-mounted sprayers, backpack sprayers, and hand-held spray bottles, and dropper bottles are used for application of herbicide. Various adjuvants may be added to the spray mixture to aid or modify the action of the herbicide or the physical characteristics of the mixture. A marker dye is often added to the spray solution to help visualize where herbicide is applied. This document is SS-AGR-258, one of a series of the Agronomy Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date October 2005.

scholarly journals Evaluation of Poinsettia Cultivars for Resistance to Pythium Root Rot Caused by Pythium aphanidermatum

2017 ◽  
Vol 27 (6) ◽  
pp. 805-812 ◽  
Author(s):  
Emma C. Lookabaugh ◽  
Brian Whipker ◽  
Barbara B. Shew
Keyword(s):  
North Carolina ◽  
Host Resistance ◽  
Root Rot ◽  
Partial Resistance ◽  
Integrated Management ◽  
Pythium Aphanidermatum ◽  
Euphorbia Pulcherrima ◽  
Predominant Species ◽  
Pythium Root Rot ◽  
Color Response

Pythium aphanidermatum is the predominant species causing pythium root rot of commercially grown poinsettia (Euphorbia pulcherrima) in North Carolina. Pythium root rot is primarily managed with strict sanitation practices and preventative fungicide applications. To determine if host resistance could play a role in the integrated management of pythium root rot, information on the susceptibility of commercial poinsettia cultivars is needed. Commercially available poinsettia cultivars were inoculated with P. aphanidermatum 3 weeks after transplant and evaluated for resistance to pythium root rot 2 months later. Thirty-four cultivars were evaluated for resistance in 2014 and 58 cultivars were evaluated in 2015, for a total of 62 cultivars evaluated. Twenty-nine cultivars were evaluated in both years. Most cultivars were susceptible to pythium root rot and none were completely resistant. However, several cultivars demonstrated partial resistance to pythium root rot. Interspecific hybrid cultivars, including Luv U Pink, had a higher level of partial resistance when compared with conventional cultivars. Partial resistance varied across bract color, response time, and plant vigor groupings. Overall, 6 of 13 partially resistant cultivars identified in 2015 had red bracts. These results indicate that growers should be able to choose among several red bract cultivars that have higher-level partial resistance to pythium root rot than others.

scholarly journals Evaluation of Caladium Cultivars for Resistance to Pythium Root Rot

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 772E-773 ◽  
Author(s):  
Zhanao Deng* ◽  
Brent K. Harbaugh ◽  
Rick Kelly ◽  
Teresa Seijo ◽  
Robert J. McGovern
Keyword(s):  
Root Rot ◽  
Plant Production ◽  
Higher Plant ◽  
Pythium Root Rot ◽  
Tuber Production ◽  
Commercial Cultivars ◽  
Greenhouse Plant ◽  
Growing Conditions ◽  
Spore Densities ◽  
Highly Virulent

Caladiums (Caladium × hortulanum) are widely grown for their bright colorful leaves. Pythium root rot, caused primarily by P. myriotylum, is one of the most important diseases in caladiums. This disease can dramatically reduce plant growth, impact plant aesthetical value, and lower tuber yield. Pythium infection in the roots may also lead to subsequent entry of Fusarium into tubers resulting in tuber rot. There has been a strong interest in the tuber production and greenhouse plant production industries to identify cultivars that are resistant or tolerant to Pythium. However, few studies have been conducted since the pathogen was identified, and little information is available regarding the existence of any possible resistance in commercial cultivars. Pythium isolates were made from diseased plants collected from different sites; their pathogenicity was confirmed using tissue culture-derived plants. Procedures were developed for oogonia spore production, inoculation, and disease severity assessment. Nineteen major commercial cultivars were inoculated at two spore densities and then maintained in greenhouses under growing conditions favorable for root rotting. Plant appearance, leaf characteristics and severity of root rotting were evaluated 2-3 times after inoculation. Observations indicated that the isolates were highly virulent. They induced visible root rot within 3-5 days, and caused a complete loss of the root system and plant death for some cultivars within 2-3 weeks after inoculation. Several cultivars, including `Candidum' and `Frieda Hemple' which are widely grown cultivars, had much less root rot, higher plant survival, and seemed to have moderate levels of resistance.

Estate Planning

EDIS ◽  
1969 ◽  
Vol 2002 (6) ◽  
Author(s):  
Josephine Turner ◽  
Vervil Mitchell
Keyword(s):  
Cooperative Extension ◽  
Cooperative Extension Service ◽  
Extension Service ◽  
Publication Date ◽  
Estate Planning ◽  
University Of Florida ◽  
Agricultural Sciences

This document is FCS 7027, one of a series of the Department of Family, Youth and Community Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: September 2002. First published: July 1978. Revised: September 2002. https://edis.ifas.ufl.edu/fy446

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