Amanda Gevens, Chair, Professor & Extension Vegetable Pathologist, UW-Madison, Dept. of Plant Pathology, 608-575-3029, Email: gevens@wisc.edu.
Currently registered fungicides for hop downy mildew and powdery mildew for Wisconsin. I have included critical information regarding active ingredients, rate, days to harvest, modes of action, as well as critical remarks. Page 134 of the Wisconsin Vegetable Production Guide (A3422 Extension Publication) https://cdn.shopify.com/s/files/1/0145/8808/4272/files/A3422-2021.pdf begins a more comprehensive and detailed section on hop fungicides and common practices.
In recent years, downy mildew has become commonplace in established hop yards of Wisconsin, with powdery mildew increasing as a more common disease concern. As yards age, additional diseases may arise including Phoma, Alternaria, and Fusarium pathogens infecting foliage and cones. Generally, fungicides with activity on powdery mildew also have control of these true fungal pathogens. Fungicides specific to downy mildew are very specialized for oomycetes/water molds such as the downy mildew pathogen – and do not control true fungal pathogens.
Downy mildew (Pseudoperonospora humuli)
| Active Ingredient | Fungicide Activity (FRAC #) | Days to harvest | Rate/acre of Commercial Product | Remarks |
|---|---|---|---|---|
| ametoctradin + dimethomorph | systemic + protectant (45+40) | 7 | 11.0-14.0 fl oz Zampro | Do not apply >40 fl oz per acre/season. Apply no more than 3 applications per season. Do not make >2 sequential applications before alternating to different mode of action. |
| copper oxychloride and copper hydroxide | protectant (M1) | 14 | 1.8 pt Badge SC | Do not mix with fosetyl aluminum. Apply as needed. |
| 0.75 lb Badge X2 | ||||
| copper oxychloride and basic copper sulfate, copper hydroxide | protectant (M1) | 14 | C-O-C-S WDG 4.0-6.0 lb | No remarks. |
| 1.33 lb Champ Dry Prill | ||||
| 1.33 lb Champ Formula II Flowable | ||||
| 1.06 lb Champ WG | ||||
| 0.75-1.5 lb Kocide 3000 | ||||
| 1.5 lb Kocide 2000 | ||||
| 2.0 lb Kentan DF | ||||
| 1.33-2.67 pt NuCop 3L | ||||
| copper ammonium complex | protectant (M1) | 14 | 2.0 qt Copper Count N | No remarks. |
| cuprous oxide | protectant (M1) | 14 | 2.0 lb Nordox | No remarks. |
| copper octanoate | protectant (M1) | 14 | 0.5-2.0 gal Cueva in 100 gal water | No remarks. |
| basic copper sulfate | protectant (M1) | 14 | 1.0-1.25 lb Cuprofix Ultra | Apply after pruning but before training. Apply again as needed on a 10 day basis after training. |
| 40 Disperss | ||||
| cyazofamid | protectant + limited systemic (21) | 3 | 2.1-2.75 fl oz Ranman | Apply prior to or at first sign of disease. Follow resistance management guidelines. Rainfast. |
| cymoxanil | locally systemic (27) | 7 | 3.2 oz Curzate DF | Apply with a protectant fungicide such as copper hydroxide. Rainfast in 2 hours. |
| dimethomorph | systemic (40) | 7 | 6.0 fl oz Forum | Do not make >3 applications per season. Addition of an adjuvant to spray mix is recommended. Good antisporulant. Rainfast. |
| famoxadone + cymoxanil | locally systemic, curative (27+11) | 7 | 8.0 oz Tanos | Use with a tank mix partner. Apply preventatively and use on a 6-8 day spray schedule. Follow resistance management guidelines. Excellent curative activity. Good leaf protectant. Rainfast. |
| fluopicolide | systemic (43) | 24 | 4.0 fl oz Presidio | Must be tank-mixed with another fungicide with a different mode of action |
| folpet | protectant (M4) | 14 | 3 lb/acre Folpan 80 WDG | Can be applied up to 4X per season at 28- day intervals. Do not apply more than 12 lb of Folpan per acre/year. Mix with a systemic fungicide starting at firs spike appearance. |
| fosetyl aluminum | upregulates resistance in the plant (33) | 24 | 2.5 Aliette | Do not tank mix with copper. Initiate application when weather conditions favor disease (warm and humid). Avoid mixing with foliar fertilizers or surfactants. |
| 5.0 lb/100 gal spray volume Linebacker | ||||
| mandipropamid | systemic (40) | 7 | 8.0 fl oz Revus | A non-ionic surfactant is recommended with use of this product. Follow resistance management guidelines. |
| mefenoxam | systemic (4) | 45 | 0.5 pt Ridomil Gold SL | Label allows drench and foliar applications. Follow resistance management guidelines. Can be highly effective and is 2-way systemic, however, downy mildew pathogen can acquire resistance. |
| metalaxyl | systemic (4) | 45 | 1.0 qt MetaStar 2E | Label allows drench and foliar applications. Follow resistance management guidelines. |
| mono and dipotassium salts of phospohorous acid | protectant, induces plant resistance, systemic (33) | 0 | 1.0-3.0 qt/100 gal water Fosphite | Do not apply at intervals of less than 3 days. Apply when conditions favor disease when shoots are 6 to 12 inches tall, after training at 5-6 ft tall, about 3 weeks after 2nd application and during bloom. |
| oxathiapiprolin + mandipropamid | protectant, systemic, and curative activity (49+40) | 7 | 5.5-8.0 fl oz/A Orondis Ultra | Begin applications prior to disease development and continue on a 7 to 10 day interval. Use higher rate when disease pressure is nigh. |
| potassium bicarbonate | protectant (NC) | 0 | 2.5-5.0 lb/100 gal spray volume Armicarb | Do not exceed mix rate of 5.0 lb/100 gal of water. Do not store unused portion of spray for more than 12 hours prior to use. |
| pyraclostrobin + boscalid | contact and locally systemic (11+7) | 14 | 14.0 oz/100 gal spray volume Pristine | Use preventatively and apply at 14-21 day intervals as needed. Follow resistance management guidelines. |
| extract of Reynoutria sachalinensis | induced systemic resistance (P5) | 0 | 1.0-4.0 qt Regalia | Use preventatively and apply at 7-day intervals as needed. Emergence to wire touch 1.0-2.0 qt recommended/wire touch through harvest 2.0-4.0 qt. OMRI approved. Has some contact fungicidal activity. |
| mono potassium phosphate and mono potassium phosphite | induces plant resistance, some protectant activity (NC) | 0 | 2.0-4.0 qt Phorcephite | Apply when conditions favor disease when shoots are 6-12 inches tall, after training at 5-6 ft tall, about 3 weeks after 2nd application, and during bloom. |
| 1.0-3.0 qt in 20 gal of water Rampart | ||||
| Bacillus pumilis QST 2808 | protectant (44) | 0 | 2.0-4.0 qt/100 gal spray volume of Sonata | Use when conditions favor disease and apply at 7-14 day intervals as needed. OMRI approved. |
Powdery mildew (Podosphaera macularis and humili)
| Active Ingredient | Fungicide Activity (FRAC #) | Days to harvest | Rate/acre of Commercial Product | Remarks |
|---|---|---|---|---|
| trifloxystrobin | surface- systemic or translaminar (11) | 14 | 1.0 oz with every 15-30 gal spray volume Flint | Apply preventatively for best results. Apply on a 10 to 14 day interval. Follow resistance management guidelines. |
| pyraclostrobin + boscalid | contact and locally systemic (11+7) | 14 | 14.0 oz/100 gal spray volume Pristine | Use preventatively and apply at 14-21 day intervals as needed. Follow resistance management guidelines. |
| myclobutanil | locally systemic (3) | 14 | 2.0-10.0 oz Rally | Emergence to training label rate is 2-4 oz/training to wire is 4-6 oz/wire to 14-day prior to harvest is 6-10 oz. Follow resistance management guidelines. |
| tebuconazole | locally systemic (3) | 14 | 4.0-8.0 fl oz Monsoon, ONSET 3.6L, Orius 3.6F, Tebustar 3.6L, Tebuzol 3.6F, Toledo 3.6F | Apply at 10 to 14 day intervals. Follow resistance management guidelines. |
| triflumizole | locally systemic (3) | 7 | 12.0 fl oz Procure 480SC | Use prior to/at disease onset and reapply on a 14 day schedule. |
| quinoxyfen | systemic protectant (13) | 21 | 4.0-8.2 fl oz Quintec | Follow resistance management guidelines, including ‘do not apply more than 4X per season.’ Minimum spray interval is 7 days. |
| metrafenone | protectant and curative (8) | 3 | 15.4 fl oz Vivando | No curative activity. Must be applied in advance of infection. Do not make more than 2 applications/year, totaling no more than 30.8 fl oz. Do not mix with oils. |
| fluopyram + tebuconazole | contact and locally systemic (11+7) | 14 | 8.0-17.0 fl oz/acre Luna Experience | Apply preventatively for best results. Apply on a 14 day interval. Follow resistance management guidelines. No more than 34 fl oz per acre per year. Also controls Botrytis. |
| cyflufenamid | protectant, curative (U6) | 0 | 6-8 oz Torino | Do not exceed two applications per year. |
| fluopyram | preventative, systemic, and curative (7) | 7 | 6.5-6.84 fl oz/acre Velum | Follow resistance management strategies. |
| fluopyram + trifloxystrobin | contact, locally systemic (11+7) | 14 | 3-7.6 fl oz/acre Luna Sensation | Apply preventatively. Apply on a 14 day interval. Follow resistance management guidelines. No more than 27.1 fl oz per acre per year. Also controls Botrytis; and Downy mildew at highest label rate. |
| flutriafol | locally systemic (3) | 7 | 5-7 fl oz/acre Rhyme | Apply preventatilvely for best restuls. Apply no more than 28 fl oz/acre per year. Follow resistance management guidelines. |
| metrafenone | preventative, curative and systemic (U8) | 3 | 15.4 fl oz Vivando | Has no curative properties. Should be tank mixed with a curative. |
| flutianil | systemic (U13) | 7 | 6-8 fl oz Gatten | Do not make more than 4 applications per year. |
| potassium bicarbonate | protectant (NC or not classified) | 0 | 2.5-5.0 lb/100 gal spray volume Armicarb 100 | Do not exceed mix rate of 5.0 lb/100 gal of water. Do not store unused portion of spray for more than 12 hours prior to use. |
| sodium bicarbonate | protectant (NC) | 0 | 4.0 oz/10 gal water spray volume Milstop | Begin application when weather favors disease and apply at 1-2 week intervals. Tighten intervals when pressure heightens. |
| copper octanoate | protectant (M1) | 14 | 0.5-2.0 gal Cueva in 100 gal water | Apply soon after training vines. |
| mono and dipotassium salts of phosphorous acid | protectant, induces plant resistance (33) | 0 | 1-3 qt/100 gal water Phosphite | Apply at 2 to 3 week intervals. Do not apply at an interval less than 3 days. |
| 1-3 qt in 20 gal of water Rampart | ||||
| extract of Reynoutria sachalinensis | induced systemic resistance (P5) | 0 | 1-4 qt Regalia | Use preventatively and apply at 7 day intervals as need. Emergence to wire-touch 1-2 qt recommended/wire-touch through harvest 2-4 qt. OMRI approved. |
| Bacillus subtilis QST 713 strain | protectant (44) | 0 | 4-6 qt/100 gal spray volume of Serenade ASO, Serenade MAX | Use when conditions favor disease and apply at 7 day intervals as needed. OMRI approved. |
| Bacillus pumilis QST 2808 | protectant (44) | 0 | 2-4 qt/100 gal spray volume of Sonata | Use when conditions favor disease and apply at 7-14 day interval as needed. OMRI approved. |
| Neem oil | Protectant (NC) | 0 | 0.5-1.0% in 25-100 gal water spray volume Trilogy | Use when conditions favor disease and apply at a 7-14 day interval as needed. OMRI approved. Also miticide/insecticide. |