Growers looking for an advantage in the fight against plant pathogens are adding microbial fungicides to their disease management strategies. Microbial fungicides, sometimes referred to as “biofungicides”, are a class of fungicides where the active ingredient is a microorganism or a microorganism’s byproduct, derived from fungi, bacteria, or plants. Microbials prevent the spread of plant pathogens using multiple modes of action (MOA), including competitive exclusion, predation, antagonistic metabolites, nutrient competition, and induced resistance in the plant host. Commercially available microbial fungicides employ two or more of these modes of action, reducing the possibility that pathogens can develop pesticide resistance. The MOA are officially (FRAC) classified as “NC”, or not classified due to the various pathways they may take.
There are many advantages to using microbial products, including short reentry intervals, short pre-harvest intervals, and good plant safety. Because these microorganisms colonize, protect, and stimulate the natural defenses in the host plant, they promote better plant health. Healthier plants are more stress and drought tolerant. Additionally, all the products in the table below are OMRI certified for organic production and labeled for a wide variety of edible species.
However, microbials work slowly, and it takes time to realize the full benefit of their use. Microbial fungicides must be applied prior to the onset of disease. They are not an effective rescue treatment for plants that are already infected and damaged by pathogens. Use them preventatively and monitor for the early onset of disease symptoms. Do not hesitate to use a conventional fungicide option to correct an issue before applying a biofungicide for ongoing prevention.
To optimize the use of microbial fungicides in a crop protection strategy, it is necessary to start clean. Follow proper sanitation procedures to ensure that there is no holdover of disease pathogens in the greenhouse. Application of microbials should start early in the crop before pest pressure develops. Follow the label instructions for the timing of reapplication as crops benefit from multiple applications to ensure a steady population of microorganisms in the environment. It is necessary to reapply frequently on foliage, while applications used at soil level remain active longer due to more favorable conditions.
Microbial fungicides have some additional handling and storage requirements. Follow label instructions concerning temperature storing conditions to maximize product efficacy and shelf life. Microbial products are often tank-mixed with conventional insecticides and fungicides, but it is important to read labels carefully to determine appropriate uses and compatibility. Please reach out to GGSPro if this information is not readily available from the product label or through online resources. Even though these biopesticides are compatible with many conventional chemicals, care should be taken by using dedicated spray equipment or ensure that the spray equipment has been thoroughly cleaned and rinsed before introducing biological based pesticides. Do not assume all foggers or ultra-low volume equipment are compatible with microbial fungicides as some use extremely high temperatures or fine screens. If you have any questions related to compatibility with your model of fogger, proper storage requirements, or product shelf-life inquiries please contact your local Griffin Sales Representative or GGSPro at ggsprotech@griffinmail.com.
Note, not all products are registered in all states. Some pesticides are restricted use in some states or regions and not others. It is the responsibility of the applicator to read and follow all label directions, remembering that labels may change. Other products may be safe and effective. Rates, application methods, and edible status are detailed in our GGSPro Insecticide & Fungicide Guides. Griffin also offers the 5th Edition GGSPro Technical Reference Guide in both English and now Spanish versions. This valuable resource outlines a wide range of pest control options and information on pollinator safety, BCA’s, scouting, weed management, plant lighting, nutrition, water quality and more!
There are many advantages to using microbial products, including short reentry intervals, short pre-harvest intervals, and good plant safety. Because these microorganisms colonize, protect, and stimulate the natural defenses in the host plant, they promote better plant health. Healthier plants are more stress and drought tolerant. Additionally, all the products in the table below are OMRI certified for organic production and labeled for a wide variety of edible species.
However, microbials work slowly, and it takes time to realize the full benefit of their use. Microbial fungicides must be applied prior to the onset of disease. They are not an effective rescue treatment for plants that are already infected and damaged by pathogens. Use them preventatively and monitor for the early onset of disease symptoms. Do not hesitate to use a conventional fungicide option to correct an issue before applying a biofungicide for ongoing prevention.
To optimize the use of microbial fungicides in a crop protection strategy, it is necessary to start clean. Follow proper sanitation procedures to ensure that there is no holdover of disease pathogens in the greenhouse. Application of microbials should start early in the crop before pest pressure develops. Follow the label instructions for the timing of reapplication as crops benefit from multiple applications to ensure a steady population of microorganisms in the environment. It is necessary to reapply frequently on foliage, while applications used at soil level remain active longer due to more favorable conditions.
Microbial fungicides have some additional handling and storage requirements. Follow label instructions concerning temperature storing conditions to maximize product efficacy and shelf life. Microbial products are often tank-mixed with conventional insecticides and fungicides, but it is important to read labels carefully to determine appropriate uses and compatibility. Please reach out to GGSPro if this information is not readily available from the product label or through online resources. Even though these biopesticides are compatible with many conventional chemicals, care should be taken by using dedicated spray equipment or ensure that the spray equipment has been thoroughly cleaned and rinsed before introducing biological based pesticides. Do not assume all foggers or ultra-low volume equipment are compatible with microbial fungicides as some use extremely high temperatures or fine screens. If you have any questions related to compatibility with your model of fogger, proper storage requirements, or product shelf-life inquiries please contact your local Griffin Sales Representative or GGSPro at ggsprotech@griffinmail.com.
Note, not all products are registered in all states. Some pesticides are restricted use in some states or regions and not others. It is the responsibility of the applicator to read and follow all label directions, remembering that labels may change. Other products may be safe and effective. Rates, application methods, and edible status are detailed in our GGSPro Insecticide & Fungicide Guides. Griffin also offers the 5th Edition GGSPro Technical Reference Guide in both English and now Spanish versions. This valuable resource outlines a wide range of pest control options and information on pollinator safety, BCA’s, scouting, weed management, plant lighting, nutrition, water quality and more!
| Product | Major Greenhouse Disease Labeled | OMRI Listed |
REI hours |
Item Number |
Size |
|---|---|---|---|---|---|
| Actinovate SP Streptomyces lydicus WYEC 108 |
Alternaria, Botrytis and powdery mildew. Drench for Pythium, Phytophthora, Rhizoctonia, Fusarium |
Yes | 1 | 71-1117 | 18 oz |
| BotryStop WP Ulocladium oudemansii (U3 Strain) |
Botrytis and Sclerotinia spp. | Yes | 4 | 71-12601 | 12 lb |
| 71-12603 | 30 lb | ||||
| Cease Bacillus subtilis stain QST 713 |
Alternaria, Botrytis, downy mildew, powdery mildew, bacterial pathogens. Drench for Fusarium, Pythium, Phytophthora and Rhizoctonia. |
Yes | 4 | 71-13301 | 1 gal |
| 71-1335 | 2.5 gal | ||||
| Companion WP Bacillus amyloliquefaciens stain ENV503 |
Alternaria, Botrytis, bacterial pathogens, Colletotrichum and powdery mildew. Drench for Fusarium, Pythium, Phytophthora, Rhizoctonia. |
Yes | 4 | 71-1372A2 | 5 lb |
| 71-1375A2 | 20 lb | ||||
| EcoSwing Extract of Swinglea glutinosa |
Alternaria, basil downy mildew, Botrytis, powdery mildew and others. |
Yes | 4 | 71-1455 | 1 qt |
| LalStop K61 WP Streptomyces sp. strain K61 |
Alternaria and aerial Rhizoctonia. Drench for Fusarium, Phytophthora, Pythium, Rhizoctonia |
Yes | 4 | 71-2061 | 0.88 oz |
| 71-2063 | 3.5 oz | ||||
| 71-2065 | 2 lb | ||||
| Obtego Trichoderma asperellum & Trichoderma gamsii |
Drench for Pythium, Phytophthora, Fusarium, Rhizoctonia and Verticillium |
Yes | 4 | 71-2105 | 5 lb |
| Regalia CG Extract of Reynoutria sachalinensis |
Alternaria, bacterial pathogens, Botrytis, Colletotrichum, Cercospora, downy mildew, Myrothecium, powdery mildew, rust and Septoria. Drench for Fusarium, Phytophthora, Pythium and Rhizoctonia |
Yes | 4 | 70-2841 | 1 qt |
| 70-2844 | 1 gal | ||||
| 70-2845 | 2.5 gal | ||||
| RootShield G & WP Trichoderma harzianum Rifai strain T-22 |
Incorporated or drenched for Pythium, Fusarium and Rhizoctonia |
Yes | 0 | 71-2781 | 40 lb |
| 71-2783 | 500 lb | ||||
| 71-2785 | 1,000 lb | ||||
| 71-2789 | 1 lb | ||||
| 71-27901 | 3 lb | ||||
| 71-27903 | 30 lb | ||||
| RootShield Plus G & WP Trichoderma harzianum Rifai strain T-22 & Trichoderma virens strain G-41 |
Incorporated or drenched for Pythium, Phytophthora, Fusarium and Rhizoctonia |
Yes | 0 | 71-27921 | 40 lb |
| 71-27931 | 500 lb | ||||
| 71-27941 | 1,000 lb | ||||
| 71-27951 | 1 lb | ||||
| 71-27961 | 3 lb | ||||
| 71-27971 | 30 lb | ||||
| Stargus Bacillus amyloliquefaciens strain F727 |
Alternaria, bacterial pathogens, Botrytis, Cercospora, Colletotrichum, downy mildew. Drench for Pythium, Phytophthora, Rhizoctonia and Sclerotinia |
Yes | 4 | 71-2950 | 2.5 gal |
| Triathlon BA Bacillus amyloliquefaciens strain D747 |
Alternaria, bacterial pathogens, Botrytis, Cercospora, downy mildew, Entomosporium, Myrothecium, powdery mildew, rust and scab. Drench for Fusarium, Pythium, Phytophthora and Rhizoctonia |
Yes | 4 | 71-3040 | 1 gal |