Marigold Diseases by primusboy

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									                  Cooperative Extension---The Pennsylvania State University

                     Plant Disease Facts
                                Department of Plant Pathology
                                 University Park, PA 16802



                     MARIGOLD DISEASES
                       Gary W. Moorman, Professor of Plant Pathology

DISEASE              SYMPTOMS                    PATHOGEN/CAUSE         MANAGEMENT

ALTERNARIA LEAF      Purplish spots form on      Alternaria             Avoid overhead
SPOT                 leaves and stems.                                  irrigation. Apply
                                                                        chlorothalonil,
                                                                        propiconazole,
                                                                        iprodione, fludioxonil,
                                                                        azoxystrobin, neem oil,
                                                                        myclobutanil, copper
                                                                        hydroxide, mancozeb, or
                                                                        thiophanate methyl +
                                                                        mancozeb.

BACTERIAL LEAF       Small (2-5 mm) circular     Pseudomonas tagetis    Destroy infected plants.
SPOT                 dead spots form on                                 Avoid overhead
                     leaves and petioles.                               irrigation.
                     Spots have purple
                     margins.

BOTRYTIS FLOWER      Flower parts brown and      Botrytis cinerea       Avoid overhead
BLIGHT               die. Gray masses of                                irrigation. Apply
                     spores form on the                                 chlorothalonil ,
                     infected tissue when                               fludioxonil,
                     wet.                                               azoxystrobin, iprodione,
                                                                        mancozeb, thiophanate
                                                                        methyl + mancozeb, or
                                                                        ferbam.

FUSARIUM WILT        Seedlings are killed. In    Fusarium oxysporum     Plant in potting mix free
                     older plants, black                                of pathogens. Destroy
                     streaks darken the                                 infected plants.
                     vascular tissue up one
                     side of the plant. Plants
                     wilt. Roots on the
                     greatly reduced root
                     system are rotted.
                     During wet weather,
                     salmon-colored spore
                     masses form on infected
                     stems.
                                                       2

LEAF BURN                  The tips and margins of     Excess boron,          Measure and apply
                           leaves yellow and die.      manganese, or          micronutrient solutions
                                                       molybdenum             carefully. Manganese
                                                                              should not be above 55
                                                                              ppm, molybdenum
                                                                              above 24 ppm, or boron
                                                                              above 3 ppm.

SEPTORIA LEAF              Oval to irregular gray to   Septoria tageticola    Avoid overhead
SPOT                       black spots with tiny                              irrigation. Apply
                           dots peppering their                               propiconazole,
                           surface (fungal fruiting                           fludioxonil or
                           structures) form first on                          chlorothalonil.
                           lower leaves and then
                           spread upward.




Alternaria leaf and stem spot.

Active Ingredients and Trade Names of the Chemicals
                                                           REI
                                                           Restricted
FRAC      Risk                                             Entry
Group No. Level     Class                Active ingredient Interval Trade names (EPA Reg. no.)
   2        3       Dicarboximide        iprodione             12     Chipco 26GT (100-1138), Chipco 26019
                                                                      (264-481), Iprodione (51036-361), Sextant
                                                                      (51036-361-59807)
    3        2      Triazole             propiconazole         24     Banner MAXX (100-741), Propiconazole
                                                                      (51036-403), Spectator (62719-346-10404),
                                                                      Kestrel (66222-41-81943)
                                         myclobutanil          24     Systhane (707-253)
    11       3      Strobilurin          azoxystrobin          4      Heritage (10182-408)
    12       2      Phenylpyrol          fludioxonil           12     Medallion (100-769)
    M        1      Chloronitrile        chlorothalonil        48     Daconil (50534-9), Exotherm Termil (70-
                                                                      223)
                                                               12     Echo (60063-7), PathGuard (60063-7-499),
                                                                      Concorde (72167-24-1812), Pegasus
                                                                      (72167-24-1812)
                    Copper, fixed        copper hydroxide      48     Kocide (352-656), Champion (55146-1)
                    Dithiocarbamate      mancozeb              24     Dithane (707-180), FORE (707-87),
                                                                      Pentathlon (1818-251)
                                         manganese + zinc      24     Protect T/O (1001-65)
                                         ferbam                24     Ferbam (45728-7)
   NC        1                           neem oil              4      Trilogy (70051-2), Triact (70051-2-59807)
Combined     1
                                                                  3

products
1+M                                                thiophanate methyl +                    Zyban (58185-31)
                                                   mancozeb

Fungicides and Fungicide Resistance Management - Certain fungicides, usually systemic fungicides, are said to be
‘at risk’ to the development of resistance if they are used repeatedly. See the Risk Level in the above table (1 = low
risk; 3 = high risk). The Fungicide Resistance Action Committee has developed a numbering system in which
chemicals with the same FRAC Group number have the same mode of action (See
http://www.frac.info/frac/index.htm). It is recommended that chemicals at high risk be used sparingly and in rotation
or mixed with chemicals with different modes of actions (different FRAC number).

NOTICE: THE USER OF THIS INFORMATION ASSUMES ALL RISKS FOR PERSONAL INJURY OR PROPERTY DAMAGE.
WARNING! PESTICIDES ARE POISONOUS. READ AND FOLLOW ALL DIRECTIONS AND SAFETY PRECAUTIONS ON LABELS.
HANDLE CAREFULLY AND STORE IN ORIGINAL LABELED CONTAINERS OUT OF THE REACH OF CHILDREN, PETS, AND
LIVESTOCK. DISPOSE OF EMPTY CONTAINERS RIGHT AWAY, IN A SAFE MANNER AND PLACE. DO NOT CONTAMINATE
FORAGE, STREAMS OR PONDS.

Where trade names are used, no discrimination is intended and no endorsement by the Cooperative Extension Service is implied.

Issued in furtherance of Cooperative Extension work, Acts of Congress, May 8 and June 30, 1914, in cooperation with the U. S. Department of
Agriculture and the Pennsylvania Legislature. D. Jackson, Director of the Cooperative Extension Service, The Pennsylvania State University.

The Pennsylvania State University is committed to the policy that all persons shall have equal access to programs, facilities,
admission, and employment without regard to personal characteristics not related to ability, performance, or qualifications as
determined by University policy or by state or federal authorities. It is the policy of the University to maintain an academic and work
environment free of discrimination, including harassment against any person because of age, ancestry, color, disability or handicap,
national origin, race, religious creed, sex, sexual orientation, or veteran status. Direct all inquiries regarding the nondiscrimination
policy to the Affirmative Action Director, The Pennsylvania State University, 201 Willard Building, University Park, PA 16802-
2801: Tel. 814/865-4700/V, 814/863-1150/TTY., University Park, PA 16802-2801: Tel. 814/865-4700/V, 814/863-1150/TTY.

								
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