PMEP Home Page --> Pesticide Active Ingredient Information --> Fungicides and Nematicides --> Fungicides, F to S --> Iprodione --> Iprodione - Fact Sheet 5/83

Iprodione - Fact Sheet 5/83

ROVRAL/CHIPCO 26019
FUNGICIDE

Rovral or Chipco 26019 is a broad spectrum, contact fungicide, with
action both on the spores and the mycelium. It provides excellent
activity against Alternaria, Botrytis, Helminthosporium, Monilinia,
Rhizoctonia and Sclerotinia. No phytotoxicity has been observed on
plants treated at recommended use rates.

CHEMICAL AND PHYSICAL PROPERTIES

1. ACTIVE INGREDIENT

- Common Name: Iprodione
- Chemical Name: 3-(3,5-dichlorophenyl)-N-(1-methylethyl)-2,4-dioxo-
1-imidazolidinecarboxamide.
- Molecular Formula: C(13)H(13)C(12)N(3)0(3)
- Molecular Weight: 330.17
- Other Names: RP26019, Glycophene (discontinued)
- Wiswesser Line Notation: T5NVNV EHJ AVMY1 & 1 CR CG EG
- Color: white to cream
- Physical State: non-hygroscopic powder
- Odor: none
- Melting Point: 136 degrees C
- Density or Specific Gravity: 1.4 g/cm cubed
- Solubility at 20 degrees C
g/l
Water equivalent to O.013
Acetone equivalent to 300
Acetonitrile equivalent to 150
Benzene equivalent to 200
Ethanol equivalent to 20
Methylenechloride equivalent to 500
Toluene equivalent to 150
- Vapor Pressure: < 2 x (-7) mm Hg at 20 degrees C
- Stability: Stable under normal dry conditions. Avoid prolonged
contact with water above pH 4. Avoid dissolution in alcohols.

2. FORMULATION

- Trade Name: Rovral for crop markets
Chipco 26019 for turf and ornamental markets
- Concentration: 50% w/w
- Color: white to light tan
- Physical State: wettable powder
- Odor: none

- Density or Specific Gravity: 10.6 Ib/ft cubed (loose),
17.6 Ib/ft cubed (packed)
- Oxidizing or reducing action: none
- Flammability: none
- Explodability: none
- Storage Stability: stable for over one year at room temperature.
- Corrosion Characteristics: none
- Use in alkaline water: the formulated product is less susceptible to
hydrolysis than the technical material. However, it is recommended, at
pH 7 and above, to use the product immediately after mixing; it will
degrade if left 12-24 hours or more in aqueous suspension above pH 7.

TOXICITY TO MAMMALS

Technical Formulated
Product Product

Acute oral LD50 -Qrat 4,400 mg/kg > 10,000 mg/kg
Acute dermal LD50 -Qrabbit > 5,000 mg/kg > 5,000 mg/kg
Acute inhalation LC50 -Qrat > 3.29 g/m3 > 1.96 g/m3
Dermal irritation -Qrabbit non-irritant moderate irritant
Eye irritationQwashed -Qrabbit non-irritant mild transient
irritant
Eye irritationQunwashed. mild transient mild transient
irritant irritant
Dermal sensitization -Qguinea pig non-sensitizer

TOXICITY TO WILDLIFE

Technical Product

Acute oral LD50 -Qmallard duck > 10,400 mg/kg

-Qbobwhite quail 930 mg/kg
Subacute dietary LC50 -Qmallard duck > 20,000 ppm
-Qbobwhite quail 9,200 ppm
96 hours LC50 -Qrainbow trout 4 ppm
-Qbluegill 6 ppm
48 hours LC50 -Qdaphnia 0.4 to 7.0 ppm

Bees: virtually non-toxic (contact, ingestion)

RESIDUE DATA

Tolerances for the combined residue of Iprodione and its metabolites in
or on the following raw agricultural commodities:

- Established tolerance 10 ppm Kiwi fruit
- Temporary tolerance 0.05 ppm Almonds
20 ppm Stone fruit
- Tolerances pending 20 ppm Apricot, Cherries (sweet,
sour), Nectarines, Peaches,
Plums (fresh prunes)

ENVIRONMENTAL DATA

Degradation.

Hydrolysis: Under laboratory conditions Iprodione showed no
significant degradation at pH 3.0; a half-life of 20 days at pH 6.0;
complete degradation in less than 24 hours at pH 9.0.
Photodegradation: In solution exposed to ultraviolet light, with a
wavelength greater than 280 nanometers, the decomposition of Iprodione
is very rapid. A half-life of 5 to 10 minutes in aqueous solution and
of 15 to 60 minutes in hexane solution is observed. In soil, the
degradation of Iprodione is enhanced only slightly upon exposure to
light with a wavelength greater than 280 nanometers.

Metabolism.

Under laboratory conditions, the half-life of Iprodione is between
20 and 70 days, in a variety of soils, under both aerobic and anaerobic
conditions. Iprodione did not generally suppress microfloral
populations or their metabolic processes, except at exaggerated
experimental rates. At normal use rates, it had no apparent effect on
symbiotic nitrogen fixation or on the oxidation/reduction processes of
the nitrogen cycle.

Mobility

Soil leaching: Laboratory experiments with various soil types
indicate that Iprodione has low mobility; this observation is confirmed
by field measurements.

Volatility: The vapor pressure of < 2 x 10(-7) mm Hg combined with
a molecular weight of 330 precludes significant loss of the compound by
volatilization.

Field dissipation

Soil: The half-life of the parent compound ranges from 7 to 40
days, depending upon soil type and climatic conditions.
Water: Based on the laboratory hydrolysis and photodegradation
studies, it is expected that Iprodione will dissipate rapidly in water
under natural field conditions.

Accumulation.

Rotated crops: No residues were found at harvest in field-grown
crops a season following the treatment year.
Irrigated crops: No accumulation of residues was observed in crops
irrigated with water coming from treated fields.
Bioaccumulation: A laboratory study with catfish showed no
tendency for Iprodione or its metabolites to significantly accumulate in
fish tissue. The bioaccumulation ratio was 14 to 46 in edible tissue.

MODE OF ACTION

Iprodione exhibits more activity on mycelial growth than spore
germination. The studies, referenced below, concerning the effect of
Iprodione on fungi, suggest:
Q no direct effect on energy production or respiration
Q no effect on cell permeability
Q no effect on DNA synthesis
Q an apparent, undefined effect on nuclear division

Reilly, C.C. and Lamoureux, G.L. 1981. The effects of the fungicide,
Iprodione, on-the mycelium of Sclerotinia sclerotiorum. Phytopathology
71:722-727.

Georgopoulos, S.G., Sarris, M., and Ziogos, B.N. 1979. Mitotic
instability in Aspergillus nidulans caused by the fungicide iprodione,
procymidone and vinclozolin. Pest. Sci. 10:389-392.

Pappas, A.C. and Fisher, D.J. 1979. A comparison of the mechanisms of
action of vinclozolin, procymidone, iprodione and prochloroz against
Botrytis cinerea. Pest. Sci. 10:239-246.

DISEASE RESISTANCE

After 3 years of commercial use only one documented case of fungal
resistance to Chipco 26019 has been reported.*

As with all the newer compounds, exclusive use of a fungicide for
disease control should be avoided. Laboratory studies suggest possible
cross-resistance among the dichloro-aniline fungicides (Iprodione,
Vinclozolin, Procymidone, DCNA and their formulations).

_____
*Chestagner, G.A. and Vassey, W.E. 1981. Occurrence of Iprodione
tolerant Fusarium nivale under field conditions. Plant Diseases 66:112-
114.

IN VITRO ACTIVITY SPECTRUM OF IPRODIONE (1)

Alternaria spp. xxx Mycosphaerella spp. xx
Aspergillus spp. xx Nigrospora musae xx
Botrytis spp. xxx Pellicularia spp. xxx
Candida albicans -Q Penicillium spp. xx
Ceratocystis ulmi xx Phellinus noxius --
Cercospora spp. -- Phoma spp. x
Cercosporella brassicae xxx Physalospora cydoniae xxx
Cladosporium musae -Q Phytophthora citrophthora --
Colletotrichum spp. (2) -- Plasmopara viticola --
Corticium salmonicolor -Q Pythium spp. --
Diaporthe citri xxx Rhizoctonia spp. xxx
Diplodia spp. xxx Rhizopus nigricans xxx
Endothia parasitica -Q Rigidoporus lignosus xx
Fusarium spp. (2) -Q Rosellinia necatrix xxx
Ganoderma pseudoferrum -Q Saccharomyces pastorianus --
Geotrichum citri-aurantii -- Sclerotinia spp. xxx
Gleosporium lacticola -Q Sclerotium spp. (2) xx
Glomerella cingulata -- Stemphylum botryosum --
Helminthosporium gramineum xxx Thielaviopsis paradoxa xx
Leucostoma persoonii xxx Trachysphaera fructigena --
Leptothyrium pomi xxx Trichophyton mentagrophytes xxx
Monilia spp. xxx Triclothecium roseum --
Mucor spp. -- Valsa mali xx

(1 ) xxx = very sensitive (2) variable, depending upon species
xx = sensitive
x = fairly sensitive
Q = not sensitive

LABELLED USES (see actual labels for more detailed instructions)

Turfgrass --

Fusarium nivale (Fusarium patch and Pink snow mold)
Fusarium roseum (Fusarium blight)
Helminthosporium spp. (Helminthosporium leaf spot and melting out)
Rhizoctonia solani (Brown patch)

Sclerotinia homoeocarpa (Dollar spot)
Typhula spp. (Gray snow mold)

Ornamentals --

Foliar application
- Alternaria zinniae (Alternaria leaf blight)
- Ascochyta chrysanthemi (Ray blight)
- Botrytis spp. (Botrytis blight)
- Botrytis tulipae (Tulip fire)
- Drechslera iridis (Ink spot)

Drench application

- Rhizoctonia spp. (Rhizoctonia)

See label for plant species

Crucifer crops --

- For crucifers grown for seed only; special local need registration
(24C) in Washington and Oregon.

- Diseases: Alternaria spp. (Alternaria leaf and pod blight)
Sclerotinia spp. (Sclerotinia white rot)

RECOMMENDATION FOR TESTING

ALMONDS: Rovral is currently being evaluated under commercial
conditions in an Experimental Use Permit Program for control of brown
rot blossom blight (Monilinia laxa).

The recommended rate is 0.5 Ib ai/A (0.125 Ib ai/l 00 gals. at 400
gallons/acre) applied at red tip and, if required, full bloom.

STONE FRUITS: Rovral is an effective foliarly applied fungicide for
control of both blossom (Monilinia laxa and Monilinia fructicola) and
fruit (Monilinia fructicola) brown rot in stone fruits at 0.5-1.0 Ib
ai/A (0.125-0.25 Ib ai/100 gals. at 400 gallons/acre). Evaluations of
cherry leafspot (Coccomyces hiemalis) and Rhizopus (Rhizopus sp.) are
also of interest.

Rovral is being evaluated under commercial conditions in 1982 in an
Experimental Use Permit Program on apricots, cherries, nectarines,
peaches, plums and prunes.

LETTUCE: For control of lettuce drop (Sclerotinia sclerotiorum) and
bottom rot (Rhizoctonia solani) the recommended rates for evaluation are
0.75-1.0 Ib ai/A (lettuce drop) and 1.0-2.0 Ib ai/A (bottom rot) applied
at 3 leaf + 10 days (if required) + 20 days (if required).

GRAPES: For control of bunch rot (Botrytis sp.), Rovral at 0.5-1.0 Ib
ai/A should be applied at early bloom, prior to bunch closing, 21 days
pre-harvest and 7 days pre-harvest.

ONIONS (sets): For control of white mold (Sclerotium cepivorum), Rovral
at 1.0 Ib ai/A should be applied in-furrow at planting (fall) and, if
necessary, as a directed spray in the spring.

GARLIC: For control of white mold (Sclerotinia sp.) Rovral at 2.0 Ib
ai/A should be applied in-furrow at planting.

PEANUTS: For control of white mold (Sclerotinia minor), Rovral at 0.75-
1.0 Ib ai/A should be applied when disease first appears and twice more
at 1 month intervals.

SUGARBEETS: For control of Phoma betae and Rhizoctonia sp. use Rovral
as a seed treatment at 1.0-2.0 oz ai/100 Ibs. of seed. Rovral will not
control Pythium sp.

BEANS (Snap, Bush & Navy): For control of white mold (Sclerotinia sp.),
Rovral at 0.5-1.0 Ib ai/A should be applied at early and full bloom.

Testing is also suggested in the following areas:

Peanut: Sclerotium rolfsii (Southern stem rot)
Lettuce: Botrytis
Beans: Botrytis
Turf: additional diseases
Ornamental: additional plant species and diseases
Small fruits
Vegetables
Post-harvest treatment
Seed treatment

For further information please contact:

RHONE POULENC INC.
AGROCHEMICAL divISION
PO. Box 125, Monmouth Junction, NJ 08852
Telephone: (201) 297-0100
or your local Rhone-Poulenc representative

Reprinted May 1983