Updated July 2023
More information at:
Vegetable Pathology Home Page (LIHREC)
PDF version of this information
The following is a list of some biopesticides and other organic fungicides labeled for cucurbit downy mildew. There are several formulations of copper not included. Each product name is followed by the active ingredient. Most products are labeled for managing other diseases which are included. Products listed with OMRI (Organic Materials Review Institute) are NOP compliant. Check state registration: each product may not be registered in all states. Also, always check with your certifier before purchasing any product. ‘No Ag Label’ indicates an agricultural label was not found for the product.
Actinovate AG. 0.0371% Streptomyces lydicus strain WYEC 108. Labeled for application to foliage for bacterial leaf spot and downy mildew, and to soil for damping-off, Fusarium wilt, Phytophthora blight, and Verticillium wilt. For best results with applications to foliage, label indicates to use a spreader-sticker. OMRI-listed. EPA Reg. No. 73314-1. Novozymes BioAg.
AVIV. 0.08% Bacillus subtilis strain IAB/BS03. Labeled for Alternaria leaf spot, anthracnose, downy mildew, gummy stem blight, powdery mildew, Phytophthora blight and also as soil treatment for root pathogens (Fusarium, Phytophthora, Pythium, and Rhizoctonia) in cucurbits. Replaces Prevont. OMRI-listed. EPA Reg. No. 91473-1-86182. Seipasa S.A.
Carb-O-Nator. 85% potassium bicarbonate. Labeled for Alternaria leaf blight, anthracnose, downy mildew, and powdery mildew. OMRI listed. EPA Reg. No. 70051-117. Certis USA.
Cease. 1.34% Bacillus subtilis strain QST 713. Broadly labeled for use on greenhouse vegetables. Labeled for angular leaf spot, anthracnose, bacterial fruit blotch, downy mildew, gummy stem blight, and powdery mildew in cucurbits. OMRI-listed. EPA Reg. No. 69592-19-68539. BioWorks, Inc.
Double Nickel 55 LC and WDG. Bacillus amyloliquefacinens strain D747, 98.8% and 25%, respectively. Broadly labeled for foliar and soil-borne diseases, including downy mildew, gummy stem blight, powdery mildew, damping-off, crown and root rot, Monosporascus vine decline, and charcoal rot in cucurbits. OMRI-listed. EPA Reg No. 70051-107 and 108, respectively. Certis USA, LLC.
ECOWORKS EC. 70% cold pressed neem oil. Labeled generally for powdery mildew, downy mildew, leaf spot, botrytis, anthracnose, blight, etc. and also several insects and mites. OMRI-listed. EPA Reg. No. 89152-4. ECOSTADT Technologies LLC.
GreenFurrow BacStop. 2.0% thyme, 2.0% clove & clove oil, 1.5% cinnamon, 1.0% peppermint & peppermint oil, and 1.0% garlic oil. Broadly labeled primarily for bacterial diseases including bacterial leaf spot, bacterial wilt, bacterial fruit blotch, downy mildew, and powdery mildew in cucurbits. Recommended used with EF400 for these and some other diseases. Exempt from EPA registration. Mar Vista Resources.
GreenFurrow EF400. 8.2% clove, 8.1% rosemary, and 6.7% peppermint. Broadly labeled including downy mildew and powdery mildew in cucurbits. Exempt from EPA registration. Mar Vista Resources.
Howler. 50% Pseudomonas chlororaphis strain AFS009. Labeled for foliar spray for diseases caused by Alternaria, Botrytis (gray mold) and Phytophthora (blight) and for downy mildew, gummy stem blight, and powdery mildew [some uses on 2(ee) label], and soil treatment for Fusarium, Phytophthora, Pythium, Rhizoctonia, and Sclerotinia. OMRI listed. EPA Reg. No. 91197-3-92488. AgBiome Innovations Inc.
KeyPlex 350 OR. 0.063% yeast extract hydrolysate from Saccharomyces cerevisiae. Combination of defensive proteins (alpha-keto acids) and secondary and micronutrients. Elicits systemic acquired resistance in plants against fungal and bacterial pathogens. Labeled for general disease control in vegetables. EPA Reg. No. 73512-4. KeyPlex.
LifeGard WG. 40% Bacillus mycoides isolate J. Biological plant activator. Labeled for anthracnose, downy mildew, gummy stem blight, and powdery mildew. OMRI-listed. EPA Reg No. 70051-119. Certis USA, LLC.
MilStop. 85% potassium bicarbonate. Broadly labeled including Alternaria leaf spot, anthracnose, downy mildew, powdery mildew, scab, and Septoria leaf spot in cucurbits. OMRI-listed. EPA Reg. No. 70870-1-68539. BioWorks, Inc.
Organocide. 5% sesame oil. Labeled broadly for several fungal diseases and insects. OMRI-listed. Exempt from EPA registration. No Ag Label. Organic Laboratories, Inc.
OSO. 5% polyoxin D zinc salt. Alternaria, anthracnose, downy mildew, gray mold, gummy stem blight, powdery mildew, and scab in cucurbits. OMRI-listed. EPA Reg No. 68173-4-70051. Certis USA, LLC.
OxiDate 2. 27% hydrogen dioxide and 2% peroxyacetic acid. Labeled for Alternaria, anthracnose, belly rot, downy mildew, Fusarium wilt, gummy stem blight, leaf spot, Phytophthora, powdery mildew, and root rots in cucurbits. OMRI-listed. EPA Reg. No. 70299-12. BioSafe Systems, LLC.
PerCarb. 85% sodium carbonate peroxyhydrate. Alternaria leaf spot, anthracnose, downy mildew, gummy stem blight, leaf spot, powdery mildew in cucurbits. OMRI-listed. EPA Reg. No. 70299-15. BioSafe Systems, LLC.
Prevont. Renamed AVIV.
Procidic. 3.5% citric acid. Labeled for damping-off, foliar diseases caused by fungal and bacterial pathogens, and post-harvest diseases. Previously marketed as Citrex. Procidic was reviewed and determined to be NOP compliant by Washington State Dept of Ag. Exempt from EPA registration. Greenspire Global, Inc.
Rango. 70% cold pressed neem oil. Generally labeled for anthracnose, downy mildew, powdery mildew, scab, and foliar diseases caused by fungal pathogens such as Alternaria and Botrytis, and for soil applications for nematodes and soil-borne fungal pathogens including Fusarium, Pythium, and Rhizoctonia solani (label has separate lists of crops and diseases). OMRI listed. EPA Reg. No. 88760-10. Terramera, Inc.
Regalia. 5% extract of Reynoutria sachalinensis. Boosts the plant’s natural defense mechanisms against certain fungal and bacterial diseases. Broadly labeled including Alternaria blight, anthracnose, Cercospora leaf spot, downy mildew, gummy stem blight, Phytophthora blight, and powdery mildew in cucurbits. OMRI-listed. EPA Reg. No. 84059-2. ProFarm Group.
Romeo. 94.1% cerevisane (cell walls of Saccharomyces cerevisiae strain LAS117). Labeled for downy mildew, Botrytis gray mold, and powdery mildew. OMRI listed. EPA Reg. No. 91810-2. Lesaffre Yeast Corporation.
Serenade ASO. 1.34% Bacillus subtilis strain QST 713. This bacterium colonizes roots when applied to soil and produces compounds that affect pathogens directly and triggers metabolic pathways to activate the plant’s natural defenses and modulate growth. Labeled for angular leaf spot, anthracnose, downy mildew, gummy stem blight, and powdery mildew and for soil diseases caused by Rhizoctonia, Pythium, Fusarium, Verticillium and Phytophthora. Serenade ASO has replaced Serenade Soil. OMRI-listed. EPA Reg. No. 264-1152. Bayer CropScience.
Serenade Opti. 26.2% Bacillus subtilis strain QST 713. New formulation. Broadly labeled including downy mildew, gummy stem blight, and powdery mildew in cucurbits. OMRI-listed. EPA Reg. No. 264-1160. Previous product names and formulations: Serenade, Serenade Max, Serenade Optimum. Bayer CropScience.
Serifel. 9.9% Bacillus amyloliquefacinens strain MBI 600. Broadly labeled for foliar diseases, including anthracnose, Alternaria leaf spot, downy mildew, gummy stem blight, and powdery mildew in cucurbits. OMRI-listed. EPA Reg No. 71840-18. BASF Corporation.
Sonata. 1.38% Bacillus pumilus strain QST 2808. Labeled for downy mildew and powdery mildew. OMRI-listed. EPA Reg. No. 264-1153. Bayer CropScience (formerly AgraQuest).
Sporan EC2. 16% rosemary oil, 10% clove oil, 10% thyme oil, 2% peppermint oil. Labeled for Alternaria leaf spot, downy mildew, and powdery mildew. OMRI-listed. Exempt from EPA registration. KeyPlex.
Stargus. Bacillus amyloliquefacinens strain F727. Labeled for downy mildew, Phytophthora blight, and root rot pathogens. OMRI-listed. EPA Reg. No. 084059-28. ProFarm Group.
Theia. 100% Bacillus subtilis strain AFS032321. Labeled for seed treatment and soil application (greenhouse and field) for soil-borne fungal diseases caused by Fusarium, Rhizoctonia, Pythium, and Phytophthora; and also for foliar application for angular leaf spot, anthracnose, downy mildew, gummy stem blight, and powdery mildew. OMRI-listed. EPA Reg. No. 94713-2-92488. AgBiome Innovations Inc.
Thyme Guard. 23% thyme oil extract. Labeled generally for diseases caused by all pathogen groups and also insect pests. Determined to be NOP compliant by Washington State Dept of Ag. Exempt from EPA registration. Agro Research International.
Thymox Control. 27% thyme oil. Proprietary nano emulsion technology. Broadly labeled for fungal diseases such as powdery mildew and grey mold, and bacterial diseases; crops not specified. OMRI listed. Exempt from EPA registration. Kemin Industries, Inc. Manufactured by Laboratoire M2.
Timorex Act. 12.5% tea tree oil. Labeled for several diseases, including downy mildew, gummy stem blight, powdery mildew, and soil-borne diseases (damping-off, crown and root rot). OMRI-listed. EPA Reg. No. 86182-3-88783. Summit Agro USA, LLC.
Timorex Gold. 23.8% tea tree oil. Labeled generally for several diseases, including anthracnose, bacterial diseases, downy mildew, and powdery mildew in cucurbits. OMRI-listed. EPA Reg. No. 70051-2. Stockton USA, LLC.
Triathlon BA. 98.85% Bacillus amyloliquefaciens strain D747. Labeled for downy mildew, gummy stem blight, powdery mildew, and applied to soil for suppressing damping off, seedling blights, and root or crown diseases caused by Pythium, Rhizoctonia, Fusarium, Phytophthora, or Verticillium spp. OMRI listed. EPA Reg. No. 70051-107-59807. OHP, Inc.
Trilogy. 70% clarified hydrophobic extract of neem oil. Labeled generally for several insects and diseases, including Alternaria, anthracnose, downy mildew, leaf spot, and powdery mildew in cucurbits. OMRI-listed. EPA Reg. No. 70051-2. Certis USA, LLC.
Zonix. 8.5% rhamnolipid biosurfactant. Kills zoospores, which is one spore type produced by Oomycete pathogens which cause diseases such as late blight and downy mildews. OMRI-listed. EPA Reg. No. 72431-1. PropTera, LLC.
Please Note: The specific directions on fungicide labels must be adhered to — they supersede these recommendations, if there is a conflict. If you are farming organically, before purchase make sure product is registered in your state and approved by your certifier. Any reference to commercial products, trade or brand names is for information only; no endorsement is intended.
Prepared by:
Margaret Tuttle McGrath
Associate Professor Emeritus (retired May 2023)
Long Island Horticultural Research and Extension Center (LIHREC)
Plant Pathology and Plant-Microbe Biology Section
School of Integrative Plant Science
College of Agriculture and Life Sciences
Cornell University
mtm3@cornell.edu