Fungicide update for berries and grapes

Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.

In the past year or two, various new fungicides have been labeled for use in berry crops and grapes; you may already be familiar with some of these, but others will be new. Not all of the new products represent new chemistries. Four major developments have driven new fungicide registrations of late and demonstrate that the disease situation in other crops can affect the availability of fungicides for berries and fruit crops as well. First of all, the threat of soybean rust has pushed along the review and registration of sterol inhibitor fungicides by the US Environmental Protection Agency (EPA); as a result, we finally received registrations for the fungicides Indar and Orbit for blueberries and cranberries. In addition, Orbit is labeled for a range of other berry crops. Various new sterol inhibitor fungicides are currently in the pipeline as well. Secondly, an outbreak of cucurbit downy mildew has driven the development of downy mildew fungicides, and currently we have three new products, Presidio, Revus, and Tanos, in our downy mildew control arsenal for grapes. Thirdly, patents have run out on a number of proprietary fungicide products and “generic” versions are now available or being developed for some commonly used fungicides. Generic products tend to be more economical, but may not have been separately evaluated and therefore you may not find them specifically recommended in the E-154 Fruit Management Guide. Do read the pesticide label carefully, as generic products may have different labels from brand name products and from each other. Lastly, as competition by generic products in the agrichemical industry increases, some companies are starting to market pre-mix products. Mixtures of two or more active ingredients may extend patent rights if companies can claim novel synergistic effects of the components in the mixture. This has led to the registration of a number of pre-mix fungicides, such as Adament, which is a mixture of Flint and Elite. Below some of the newer fungicides and products with expanded or modified labels:

Adament (tebuconazole and trifloxystrobin) is a mixture of a systemic (tebuconazole) and surface-systemic (trifloxystrobin) fungicide. It is a broad-spectrum fungicide that is labeled for control of multiple diseases on grapes, cherries, peaches, and nectarines. Adament is rainfast when dry, generally within two hours. Adament is effective against cherry leaf spot, brown rot, and powdery mildew on cherries, and powdery mildew in grapes. It has been moderately effective against Botrytis bunch rot. More research is needed to evaluate its efficacy against Phomopsis in grapes. Adament is best used as a protectant. Do not apply this product on ‘Concord’ grapes, as crop injury may result. Do not make more than two consecutive applications or a total of six (grapes) and four (stone fruit) applications per season.

Equus (chlorothalonil) has the same active ingredient as Bravo and is available as Equus 720 SST, Equus DF, and Equus 500 ZN. It is labeled for stone fruit, blueberry, and cranberry. The efficacy of this product has not been specifically evaluated in Michigan.

Indar (fenbuconazole) is a systemic sterol inhibitor fungicide labeled for control of a wide range of diseases, including those caused by Monilinia spp., in apples, cherries, peaches, nectarines, plums, apricots, blueberries, and cranberries. Indar is available in a 2F (flowable) or 75WSP formulation. Indar has preventative and curative properties, but it is best to use it on a preventative program. Do not make ground or aerial applications within 75 feet of bodies of water. The PHI is 30 days in blueberries and cranberries.

Nevado (iprodione) has the same active ingredient as Rovral. It is labeled for use in stone fruit, grapes, strawberries, raspberries, blackberries, currants, and gooseberries. The efficacy of this product has not been specifically evaluated in Michigan.

Orbit (propiconazole) is a systemic sterol inhibitor fungicide labeled for a wide range of diseases in blueberries, raspberries, blackberries, cranberries (Oregon, Washington, and Wiscosin only), gooseberries, currants, strawberries, and stone fruit. Orbit has preventative and curative properties. The PHI is 30 days in all berry crops, except cranberries (PHI is 45 days) and strawberries (PHI is 0 days). Do not apply Orbit to ‘Stanley’ plums within 21 days of harvest.

Orius (tebuconazole) has the same active ingredient as Elite. It is labeled for use in stone fruit and grapes and is available as Orius 45DF and Orius 45WP. The efficacy of this product has not been specifically evaluated in Michigan.

Presidio (fluopicolide) is a new systemic fungicide which is active against diseases caused by downy mildews and other oomycetes in grapes and vegetables. This fungicide has a novel mode of action and has protective, curative, eradicative, and antisporulant properties. Presidio is locally systemic and translaminar and moves systemically via xylem tissue. Furthermore, Presidio is compatible with many fungicides and insecticides and is rainfast in two hours. The PHI for grapes is 21 days; no more than two sequential applications are allowed. A tankmix with another fungicide with a different mode of action must be used with Presidio for resistance management.

PropiMax (propiconazole) is a systemic sterol inhibitor fungicide similar to Orbit that is labeled for control of a range of diseases in blueberries, raspberries, blackberries, cranberries (Oregon, Washington, Wisconsin only), and stone fruit. Do not apply PropiMax to cherries or “Stanley-type” plums. PropiMax has not been specifically evaluated in Michigan. The PHI is 30 days for berries other than cranberries (45 days).

Revus (mandipropamid) is a new systemic fungicide which is active against downy mildew in grapes and vegetables. It has preventative and limited curative properties. A maximum of four sprays and two sequential sprays is allowed. The addition of a spreading/penetrating type adjuvant such as a non-ionic based surfactant or crop oil concentrate is recommended. The PHI is 14 days for grapes.

Serenade Max (Bacillus subtilis) is a protectant biofungicide that is OMRI listed and therefore can be used in organic production. Serenade Max is a more concentrated version of Serenade. It is labeled for use against a variety of blueberries, strawberries, raspberries, blackberries, cranberries, gooseberries, currants, pome fruit and stone fruit. Serenade has a zero-day pre-harvest interval and a four-hour re-entry interval. Serenade has been fairly effective against mummy berry and anthracnose in blueberry; and downy mildew, black rot, and Phomopsis in grapes. Adding a non-phytotoxic spray adjuvant, such as NuFilm is recommended.

Sonata (Bacillus pumilis) is a protectant biofungicide that is OMRI listed and therefore can be used in organic production. Sonata is labeled for use on grapes, blueberries, strawberries, raspberries, blackberries, gooseberries and currants. The label lists control of leaf rust and powdery mildew in berry crops, and powdery mildew in strawberries and grapes. Sonata has a zero-day pre-harvest interval and a four-hour re-entry interval. Sonata has been moderately effective against powdery mildew, downy mildew, and Phomopsis in grape trials in Michigan. Adding a non-phytotoxic spray adjuvant, such as NuFilm is recommended.

Tanos (famoxadone and cymoxanil) is a new, broad-spectrum fungicide for control of downy mildew in grapes and suppression of anthracnose, Pseudomonas blight, and spur blight in raspberries and blackberries. It has curative and locally systemic properties against downy mildews. Tanos rapidly penetrates into plant tissues and is rainfast within one hour of application. It must be tank-mixed with a contact fungicide labeled for that crop (e.g., mancozeb, captan or copper). A maximum of nine applications of Tanos including other group 11 (strobilurin) fungicides is allowed per season. The PHI is 30 days for grapes and zero days for raspberries and blackberries.

Tebuzol (tebuconazole) has the same active ingredient as Elite and is available as Tebuzol 45DF. It is labeled for use in stone fruit and grapes. The efficacy of this product has not been specifically evaluated in Michigan.

Thiophanate Methyl (thiophanate methyl) has the same active ingredient as Topsin M. It is labeled for use in apples, pears, stone fruit, grapes, and strawberries. The efficacy of this product has not been specifically evaluated in Michigan.

Dr. Schilder’s work is funded in part by MSU‘s AgBioResearch.