Disease Control

NOTE: For the disease control products listed below, one product trade name and formulation is provided for each active ingredient (common name) as an example of rates, preharvest interval (PHI), restricted entry interval (REI), and special instructions. In many cases, there are other products available with the same active ingredient. Please see Table 25 and Fungicides and Bactericides Alphabetical Listing by Trade Name for more information on products with the same active ingredients.

The symbol OG   indicates a product is listed by the Organic Materials Review Institute (OMRI) as approved for use in organic production. See Organic Certification section for more detail.

Botrytis Leaf Blight

Avoid close planting and orient rows in the direction of prevailing winds. Do not plant on poorly-drained areas. Plow under crop debris after harvest. Remove cull piles and practice crop rotation. Avoid excessive nitrogen fertilization as this increases canopies and susceptibility. Plant less susceptible cultivars. Irrigate early in the day to reduce leaf wetness periods. Incorporate crop residues after harvest. Apply fungicides based on a disease forecast system (i.e., BOTCAST). Disease development, based on weather conditions near your farm, can be monitored on-line (www.newa.cornell.edu).

For dry bulb onions:

azoxystrobin (Quadris): 9.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11.

azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 3.2 pt/A; PHI 7d, REI 12h, Groups 11 & M5.

azoxystrobin plus difenoconazole (Quadris Top): 12.0 to 14.0 fl oz/A; PHI 7d, REI 12h, Groups 11 & 3.

azoxystrobin plus propiconazole (Quilt): 14.0 to 27.5 fl oz/A; PHI 14d, REI 12h, Groups 11 & 3.

boscalid (Endura): 6.8 oz/A; PHI 7d, REI 12h, Group 7. 

chlorothalonil (Bravo Weather Stik): 1.0 to 3.0 pt/A; PHI 7d, REI 12h, Group M5.  To suppress Botrytis neck rot in storage, a minimum of 3 weekly applications prior to lifting using 1.25 to 1.8 lb/A is recommended.

cyprodinil (Vanguard): 10.0 oz/A; PHI 7d, REI 12h, Group 9.

cyprodinil plus fludioxonil (Switch 62.5 WG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12.

difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d, REI 12h, Group 3 & 9. Apply in sufficient volume to achieve thorough coverage.

fluazinam (Omega 500F): 1.0 pt/A; PHI 7d, REI 12h to 24h (24h for hand weeding), Group 29.

fluopyram plus pyrimethanil (Luna Tranquility): 16 to 27 fl oz/A; PHI 7d, REI 12h, Groups 7 & 9. Do not make more than 2 sequential applications before alternating to a non group 7 or 9 fungicide.

fluxapyroxad plus pyraclostrobin (Merivon): 8.0 to 11.0 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset.

iprodione (Rovral 4F): 1.5 pt/A or 1.0 pt/A (if tank-mixed); PHI 7d, REI 24h, Group 2.

mancozeb (Dithane F45): 2.4 qt/A; PHI 7d, REI 24h, Group M3.

penthiopyrad (Fontelis): 16 to 24 oz/A; PHI 3d, REI 12h, Group NC.

polyoxin D (OSO 5%SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

potassium phosphite plus chlorothalonil (Catamaran): 4.0 to 7.0 pt/A; PHI 7d, REI 12, Groups 33 & M5.

propiconazole (Tilt): 4.0 to 8.0 oz/A; PHI 14d, REI 12, Group 3.

pyraclostrobin plus boscalid (Pristine): 14.5 to 18.5 oz/A; PHI 7d, REI 12h, Groups 11 & 7. Do not make more than 2 sequential applications of Pristine before alternating with a fungicide with a different mode of action.

pyrimethanil (Scala SC Fungicide): 18.0 fl oz/A; PHI 7d, REI 12h, Group 9. 

For green onions, or shallots:

azoxystrobin (Quadris): 9.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11.

azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 3.2 pt/A; PHI 14d, REI 12h, Groups 11 & M5. See label for tank mix precautions.

azoxystrobin plus difenoconazole (Quadris Top): 12.0 to 14.0 fl oz/A; PHI 1d, REI 12h, Groups 11 & 3.

azoxystrobin plus propiconazole (Quilt): 14.0 to 27.5 fl oz/A; PHI 0d, REI 12h, Groups 11 & 3.

boscalid (Endura): 6.8 oz/A; PHI 7d, REI 12h, Group 7. Use higher rate and shorter interval when disease pressure is high. Do not make more than 1 application of Endura before alternating with a fungicide with a different mode of action (FRAC group).

chlorothalonil (Bravo Weather Stik): 1.5 to 3.0 pt/A; PHI 14d, REI 12h, Group M5. When disease is present, use the higher rate.

cyprodinil (Vanguard): 10.0 oz/A; PHI 7d, REI 12h, Group 9.

cyprodinil plus fludioxonil (Switch 62.5 WDG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12.

difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 14d, REI 12h, Group 3 & 9.

fluopyram plus pyrimethanil (Luna Tranquility): 16 to 27 fl oz/A; PHI 7d, REI 12h, Groups 7 & 9. Do not make more than 2 sequential applications before alternating to a non group 7 or 9 fungicide.

fluxapyroxad plus pyraclostrobin (Merivon): 8.0 to 11.0 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset.

penthiopyrad (Fontelis): 16.0 to 24.0 oz/A; PHI 3d, REI 12h, Group NC.

polyoxin D (OSO 5%SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

potassium phosphite plus chlorothalonil (Catamaran): 4-7 pt/A; PHI 14d, REI 12, Groups 33 & M5.

propiconazole (Tilt): 4.0 to 8.0 oz/A; PHI 0d, REI 12, Group 3.

pyraclostrobin plus boscalid (Pristine): 14.5 to 18.5 oz/A; PHI 7d, REI 12h, Groups 11 & 7. Do not make more than 2 sequential applications of Pristine before alternating with a fungicide with a different mode of action.

pyrimethanil (Scala SC Fungicide): 18 fl oz/A; PHI 7d, REI 12h, Group 9.

Neck Rot (Botrytis alli)

Primarily a storage disease. Do not apply nitrogen late in the season and avoid high-density planting. Undercut bulbs to promote drying. Allow the tops to dry completely and have tight necks before topping.  Avoid condensation on bulbs during storage. Maintain storage environment at 32°F to 33°F and 70% to 75% relative humidity. Fungicides applied to control Botrytis blight may also decrease neck rot.

azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 3.2 pt/A; PHI 14d, REI 14h, Groups 11 & M5.  Suppression only. See label for tank mix precautions.

cyprodinil plus fludioxonil (Switch 6.25 WG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12. Suppression only. 

fluazinam (Omega 500F): 1 pt/A; PHI 7d, REI 48h, Group 29.

fluxapyroxad + pyraclostrobin (Merivon): 8.0 to 11.0 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset.

iprodione (Rovral 4F): 1.5 pt/A or 1.0 pt/A (if tank-mixed); PHI 7d, REI 24h, Group 2.

mancozeb (Dithane M45): 2.4 qt/A; PHI 7d, REI 24h, Group M3.

polyoxin D (OSO 5%SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

pyraclostrobin plus boscalid (Pristine): 14.5 to 18.5 oz/A; PHI 7d, REI 12h, Groups 11 & 7.

pyrimethanil (Scala SC Fungicide): 18.0 fl oz/A; PHI 7d, REI 12h, Group 9.

Downy Mildew (Peronospora destructor)

The fungus overwinters in infected bulbs or sets and on other host plants, in cull piles, and in fall-seeded onion. Only a few spores are needed to initiate an epidemic. Eliminate cull piles, volunteer onion plants, and wild Allium species. Practice a 3- to 4-year rotation. Plant only on well-drained land. Apply fungicides when mildew is present in the area and weather favors disease increase based upon a disease forecasting system (i.e., DOWNCAST).  Disease development, based on weather conditions near your farm, can be monitored online (www.newa.cornell.edu).

For dry bulb onions:

acibenzolar-s-methyl (Actigard 50 WG): 0.75 to 1.0 oz/A; PHI 7d, REI 12h, Group 21. Actigard acts as a plant activator and should be applied preventatively.

ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 and 40.

azoxystrobin (Quadris): 9.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11.

azoxystrobin plus chlorothalonil (Quadris Opti): 2.4 to 3.7 pt/A; PHI 7d, REI 12h, Groups 11 & M5. See label for tank mix precautions.

copper hydroxide (Kocide 3000): 0.75 to 1.5  lb/A; PHI 0d, REI 48h, Group M1. Can cause phytotoxicity to leaves. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

cyazofamid (Ranman 400 SC): 2.75 to 3.0 fl oz/A; PHI 0d, REI 12h, Group 21.

dimethomorph (Forum): 6.0 fl oz/A; PHI 0d, REI 12h, Group 40. Forum must be applied as a tank mix with another fungicide with a different mode of action.

famoxadone plus cymoxanil (Tanos):  8.0 oz/A; PHI 3d, REI 12h, Groups 11 & 27. Must be tank mixed with an appropriate contact fungicide with a different mode of action. Do not alternate or tank mix with other Group 11 fungicides. 

fenamidone (Reason 500 SC): 5.5 fl oz/A; PHI 7d, REI 12h, Group 11. Do not make more than 1 application of Reason before alternating to a non-Group 11 fungicide.

fluazinam (Omega 500F): 1.0 pt/A; PHI 7d, REI 48h, Group 29.

fluxapyroxad plus pyraclostrobin (Merivon): 8.0 to 11.0 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset. For supression only.

fosetyl-Al (Aliette): 2.0 to 3.0 lb/A; PHI 7d, REI 12h, Group 33. Do not tank mix with copper.

mancozeb (Dithane M45): 2.4 qt/A; PHI 7d, REI 24h, Group M3.

mancozeb plus copper hydroxide (ManKocide): 2.5 lb/A; PHI 7d, REI 48h, Groups M3 & M1.

mandipropamid (Revus): 8.0 fl oz/A; PHI 7d, REI 4h, Group 40.

mefenoxam plus chlorothalonil (Ridomil Gold Bravo SC): 2.5 pt/A; PHI 7d, REI 48h, Groups 4 & M5.

mefenoxam plus copper hydroxide (Ridomil Gold Copper): 2.0 lb/A; PHI 10d, REI 48h, Groups M3 & M1.

mefenoxam plus mancozeb (Ridomil Gold MZ): 2.5 lb/A; PHI 7d, REI 48h, Groups 4 & M3.

oxathiapiprolin plus chlorothalonil (Orondis Opti): 1.75 to 2.5 pt/A; PHI 7d, REI 12h, Groups 49 & M5.

oxathiapiprolin plus mandipropamid (Orondis Ultra): 5.5 to 8.0 fl oz/A; PHI 7d, REI 4h, Groups 49 & 40.

phosphorous acid (Fosphite): 1.0 to 3.0 qt/100 gal; PHI 0d, REI 4h, Group 33. Do not apply to heat or moisture stressed plants or to plants recently treated with copper.

potassium phosphite plus chlorothalonil (Catamaran): 4.0 to 7.0 pt/A; PHI 7d, REI 12, Groups 33 & M5.

pyraclostrobin (Cabrio EG): 12.0 oz/A; PHI 7d, REI 12h, Group 11.

pyraclostrobin plus boscalid (Pristine): 18.5 oz/A; PHI 7d, REI 12h, Groups 7 & 11. For suppression only. Rotate with a downy mildew fungicide with a different mode of action.

zoxamide plus chlorothalonil (Zing!): 30 fl oz/A; PHI 7d, REI 12h, Groups 22 & M3.

zoxamide plus mancozeb (Gavel 75 DF): 1.5 to 2 lb/A; PHI 7d, REI 48h, Groups 22 & M3.

Green or bunching:

ametoctradin plus dimethomorph (Zampro): 14.0 fl oz/A; PHI 0d, REI 12h, Groups 45 and 40.

azoxystrobin (Quadris): 9.0 to 15.5 fl oz/A; PHI 0d, REI 4h, Group 11.

azoxystrobin plus chlorothalonil (Quadris Opti): 2.4 to 3.7 pt/A; PHI 14d, REI 12h, Groups 11 & M5. See label for tank mix precautions.

copper hydroxide (Kocide 3000): 0.75 to 1.5  lb/A; PHI 0d, REI 48h, Group M1. Can cause phytotoxicity to leaves. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

cyazofamid (Ranman 400 SC): 2.75 to 3.0 fl oz/A; PHI 0d, REI 12h, Group 21. 

dimethomorph (Forum): 6.0 fl oz/A; PHI 0d, REI 12h, Group 40. Forum must be applied as a tank mix with another fungicide with a different mode of action.

famoxadone plus cymoxanil (Tanos):  8.0 oz/A; PHI 3d, REI 12h, Groups 11 & 27. Must be tank mixed with an appropriate contact fungicide with a different mode of action. Do not alternate or tank mix with other Group 11 fungicides.

fluxapyroxad plus pyraclostrobin (Merivon): 8.0 to 11.0 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset. For supression only. 

mandipropamid (Revus): 8.0 fl oz/A; PHI 7d, REI 4h, Group 40.

mefenoxam plus chlorothalonil (Ridomil Gold Bravo SC): 2.5 pt/A; PHI 14d, REI 48h, Groups 4 & M5.

mefenoxam plus copper hydroxide (Ridomil Gold Copper): 2.0 lb/A; PHI 7d, REI 48h, Groups M3 & M1.

oxathiapiprolin plus chlorothalonil (Orondis Opti): 1.75 to 2.5 pt/A; PHI 14d, REI 12h, Groups 49 & M5.

oxathiapiprolin plus mandipropamid (Orondis Ultra): 5.5 to 8.0 fl oz/A; PHI 7d, REI 4h, Groups 49 & 40.

potassium phosphite + chlorothalonil (Catamaran): 4.0 to 7.0 pt/A; PHI 14d, REI 12, Groups 33 & M5.

pyraclostrobin (Cabrio EG): 12.0 oz/A; PHI 7d, REI 12h, Group 11.

pyraclostrobin plus boscalid (Pristine): 18.5 oz/A; PHI 7d, REI 12h, Groups 7 & 11. For suppression only. Rotate with a downy mildew fungicide with a different mode of action.

zoxamide plus chlorothalonil (Zing!): 30 fl oz/A; PHI 7d, REI 12h, Groups 22 & M3.

zoxamide plus mancozeb (Gavel 75 DF): 1.5 to 2 lb/A; PHI 7d, REI 48h, Groups 22 & M3.

Purple Blotch (Alternaria porri)

The pathogen overwinters in plant residue from onions and onion-related plants. Disease development is favored by warm, moist conditions. Avoid Sweet Spanish onions because they are extremely susceptible. Plow under crop residues after harvest. Rotate with non-hosts. Select sites and practice irrigation to enhance rapid drying of foliage. Apply fungicides as canopy becomes denser and leaf-wetness periods increase. Purple blotch disease development, based on weather conditions near your farm, can be monitored on-line (www.newa.cornell.edu).

azoxystrobin (Quadris): 6.0 to 12.0 fl oz/A; PHI 0d, REI 4h, Group 11. Do not rotate with other Group 11 fungicides.

azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 3.2 pt/A; PHI 7d (dry) and 14d (green), REI 12h, Groups 11 & M5. See label for tank mix precautions.

azoxystrobin plus difenoconazole (Quadris Top): 12.0 to 14.0 fl oz/A; PHI 7d, REI 12h, Groups 11 & 3. 

azoxystrobin plus propiconazole (Quilt): 14.0 to 27.5 fl oz/A; PHI 14d (dry) and 0d (green), REI 12h, Groups 11, 7 & 3).

Bacillus amyloliquefaciens strain D747 (DoubleNickelOG): 0.25 to 3.0 lb/A; PHI 0d, REI 4 h, Group 44. Disease suppression only. For improved control; mix or rotate with a chemical fungicide.

boscalid (Endura): 6.8 oz/A; PHI 7d, REI 12h, Group 7.

chlorothalonil (Bravo Weather Stik): 1.0 to 3.0 pt/A; PHI 7d (dry) and 14d (green), REI 12h, Group M5.

copper hydroxide (Kocide 3000): 0.75-1.5 lb/A; PHI 0d, REI 48h, Group M1. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.

cyprodinil (Vanguard): 10.0 oz/A; PHI 7d, REI 12h, Group 9.

cyprodinil plus fludioxonil (Switch 62.5 WDG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12.

difenoconazole plus benzovindiflupyr (Aprovia Top): 10.5 fl oz/A; PHI 7d, REI 12h, Groups 3 & 7. No more than 2 sequential applications before alternating to a non-Group 7 fungicide.

difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d (dry bulb); PHI 14d (green), REI 12h, Group 3 & 9. Apply in sufficient volume to achieve thorough coverage. 

famoxadone plus cymoxanil (Tanos):  8.0 oz/A; PHI 3d, REI 12h, Groups 11 & 27. Must be tank mixed with an appropriate contact fungicide with a different mode of action. Do not alternate or tank mix with other Group 11 fungicides.

fenamidone (Reason 500 SC): 5.5 fl oz/A; PHI 7d, REI 12h, Group 11. Do not rotate with other Group 11 fungicides. 

fluazinam (Omega 500F): 1.0 pt/A (dry bulb only); PHI 7d, REI 12-24h, Group 29.

fluopyram plus pyrimethanil (Luna Tranquility): 16 to 27 fl oz/A; PHI 7d, REI 12h, Groups 7 & 9. Do not make more than 2 sequential applications before alternating to a non group 7 or 9 fungicide.

fluxapyroxad plus pyraclostrobin (Merivon): 5.5 to 11 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset.

iprodione (Rovral 4F): 1.5 pt/A (dry bulb only); PHI 7d, REI 24h, Group 2. Do not make more than 5 applications per season. If tank-mixing with another chemical registered for purple blotch, reduce iprodione rate to 1 pt/A.

mancozeb (Dithane F45): 2.4 qt/A (dry bulb only); PHI 7d, REI 24h, Group M3.

mancozeb plus copper hydroxide (ManKocide): 2.5 lb/A (dry bulb only); PHI 7d, REI 48h, Groups M3 & M1.

penthiopyrad (Fontelis): 16.0 to 24.0 oz/A; PHI 3d, REI 12h, Group NC.

polyoxin D (OSO 5%SC): 3.75 to 13.0 fl oz/A; PHI 0d, REI 4h, Group 19.

potassium phosphite plus chlorothalonil (Catamaran): 4.0 to 7.0 pt/A; PHI 14d, REI 12, Groups 33 & M5.

propiconazole (PropiMax EC): 4.0 to 8.0 fl oz/A; PHI 14d bulb; PHI 0d green, REI 12h, Group 3.

pyraclostrobin (Cabrio EG): 8.0 to 12.0 oz/A; PHI 7d, REI 12h, Group 11. Do not exceed 6 applications per season or 72 oz/A. Do not rotate with other Group 11 fungicides.

pyraclostrobin plus boscalid (Pristine): 10.5 to 18.5 oz/A; PHI 7d, REI 12h, Groups 7 & 11. Do not rotate with another Group 11 fungicide.

pyrimethanil (Scala SC): 18 fl oz (alone) 9 fl oz (tank mixed)/A ; PHI 7d, REI 12h, Group 9.

tebuconazole (Orius 3.6F): 4.0 to 6.0 fl oz/A (for dry onion); PHI 7d, REI 12h, Group 7.

Stemphylium leaf blight (Stemphylium vesicarium)

Symptoms appear as target-like brown lesions, lacking the purple margins seen with purple blotch. The pathogen overwinters in plant residues from onions and onion-related plants. Disease development is favored by warm, moist conditions. Plow under crop residues after harvest. Rotate with non-hosts. Select sites and practice irrigation to enhance rapid drying of foliage. Apply fungicides as canopy becomes denser and leaf-wetness periods increase.

difenoconazole plus benzovindiflupyr (Aprovia Top): 10.5 fl oz/A; PHI 7d, REI 12h, Groups 3 & 7. No more than 2 sequential applications before alternating to a non-Group 7 fungicide.

difenoconazole plus cyprodinil (Inspire Super): 16.0 to 20.0 fl oz/A; PHI 7d (dry bulb); PHI 14d (green), REI 12h, Group 3 & 9. Apply in sufficient volume to achieve thorough coverage.

fluopyram plus pyrimethanil (Luna Tranquility): 16 to 27 fl oz/A; PHI 7d, REI 12h, Groups 7 & 9. Do not make more than 2 sequential applications before alternating to a non group 7 or 9 fungicide.

fluxapyroxad plus pyraclostrobin (Merivon): 5.5 to 11 fl oz/A; PHI 7d, REI 12, Groups 7 & 11.  For best results, begin applications before disease onset.

iprodione (Rovral 4F): 1.5 pt/A (dry bulb only); PHI 7d, REI 24h, Group 2. Do not make more than 5 applications per season. If tank-mixing with another chemical registered for purple blotch, reduce iprodione rate to 1 pt/A.

pyraclostrobin (Cabrio EG): 8.0 to 12.0 oz/A; PHI 7d, REI 12h, Group 11. Do not exceed 6 applications per season or 72 oz/A. Do not rotate with other Group 11 fungicides.

pyraclostrobin plus boscalid (Pristine): 10.5 to 18.5 oz/A; PHI 7d, REI 12h, Groups 7 & 11. Do not rotate with another Group 11 fungicide.

White Rot (Sclerotium cepivorum)

White rot is associated with soil-borne inoculum; repeated cropping of Allium species results in increased disease over time. The sclerotia can persist in the soil for up to 20 years in the absence of a host. Select fields with no history of this disease. Use only disease-free transplants. Soil fumigation may be useful. Stimulating the sclerotia to germinate with onion exudate mimics (diallyl disulphide) can reduce soil inoculum.

azoxystrobin plus propiconazole (Quilt Xcel): 17.5 to 26 fl oz/A; PHI 14d, REI 12h, Group 11 & 3.

Bacillus amyloliquefaciens strain D747 (DoubleNickelOG): 0.12 to 1.0 lb/A as a soil drench; PHI 0d, REI 4 h, Group 44.

boscalid (Endura): 6.8 oz/A; PHI 7d, REI 12h, Group 7. Apply in-furrow.

cyprodinil plus fludioxonil (Switch 6.25 WG): 7.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12. Apply at planting as in-furrow spray.

fludioxonil (Cannonball): 7.0 oz/A (0.5 oz/1,000 ft row); PHI 7d, REI 12h, Group 12.

penthiopyrad (Fontelis): 16.0 to 24.0 oz/A; PHI 3d, REI 12h, Group NC.

tebuconazole (Orius 3.6F): 20.5 fl oz/A (dry onion); PHI 7d, REI 12h, Group 7. Apply in a 4-6 inch band into/over each furrow. May also be applied by chemigation.

thiophanate methyl (Topsin M 70WP): 2.0 lb/A; REI 72h, Group 1. Apply in furrow.