Disease Control

NOTES: 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 26 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 details.

Anthracnose (Colletotrichum lindemuthianum)

Anthracnose is common in beans. The causal fungus can be seedborne and may also survive on dry, undecomposed crop residues for up to 5 years. Symptoms begin as red spots on leaves and pods that develop into black lesions. Leaf veins can turn red-brown. Start with certified, disease-free seed and use resistant cultivars. Fungicides may be applied as seed treatments or foliar sprays.

• azoxystrobin (Quadris F): 6.0 to 15.5 fl oz/A; PHI 14d (dry), 0d (succulent), REI 4h, Group 11.
• azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 2.4 pt/A; PHI 14d, REI 12h, Groups 11 & M5. DRY bean only. See label for tank mix precautions.  
• azoxystrobin plus propiconazole (Quilt Xcel): 10.5 to 14.0 fl oz/A; PHI 7d succulent; PHI 14d dry, REI 12h, Groups 11 & 3. May cause crop injury. See label for restrictions and warning
• chlorothalonil (Bravo Weather Stik): 1.375 to 2.0 pt/A (dry); PHI14d (dry), REI 12h, Group M05. Labeled for Anthracnose of dry bean varieties only. 
• fluxapyroxad plus pyraclostrobin (Priaxor Xemium): 4.0 to 8.0 fl oz/A; PHI 7d (succulent), 21d (dry), REI 12 h, Groups 7 & 11. See label for livestock feeding restrictions.
• penthiopyrad (Fontelis): 14.0 to 30.0 fl oz/A (succulent) 14.0 to 20.0 fl oz/A (dry) ; PHI 0d, REI 12h, Group 7. Maximum 2 applications per year. See label for specific application methods.
• potassium bicarbonate (PB 133, AKA MilStop SP^OG): 2.0 to 5.0 lb/100 gal; PHI 0d, REI 1h. May be used in greenhouse. See label for small volume applications.
• propiconazole (Tilt): 4.0 fl oz/A; PHI 7d (succulent) 0d (dry), REI 24h, Group 3.
• Pseudomonas chloraphis (Howler^OG): 2.5 to 7.5 lbs/A; PHI 0d, REI 4h, Group BM 02. Use preventatively.
• pyraclostrobin (Headline): 6.0 to 9.0 fl oz/A; PHI 7d (succulent) to 21d (dry), REI 12h, Group 11. See label for livestock feeding restrictions. Apply at the beginning of flowering. Do not make more than 2 applications/ before rotating to a non-Group 11 fungicide.
• Reynoutria sachalinensis extract (Regalia): 1.0 to 4.0 qt/A ground application; PHI od, REI 4h, Group P05. Application to ensure thorough coverage. See label for specific application instructions.
• thiophanate-methyl (Topsin 4.5 FL): 20 to 40 fl oz/A; PHI 14d (snap) to 28d (dry), REI 24h (succulent), 72h (dry), Group 1. Rate is dependent on crop phenology, see label for details.

Downy Mildew-Lima Beans (Phytophthora phaseoli)

Downy mildew appears as a dense mat of white mycelium on infected pods. Sclerotia are not present. There is often a reddish-brown border between healthy and diseased tissue. Resistant lima bean varieties are available. Only Phaseolus species are susceptible. Apply seed treatments to protect germinating seedlings against soilborne inoculum. Plow under infected debris in fall. Rotate with crops other than beans for two years.

• chlorothalonil (Bravo Weather Stik): 1.375 to 2 pt/A (dry); PHI 14d (succulent), REI 12h, Group M05. Labeled for downy mildew of dry bean varieties only. 
• copper hydroxide (Kocide 3000): 0.5 to 1.25 lb/A; PHI 0d, REI 48h, Group M01. Do not apply in a spray solution having a pH less than 6.5 or tank mix with Aliette.
• cyazofamid (Ranman 400SC): For succulent beans ONLY. 2.75 fl oz/A; PHI 0d, REI 12h, Group 21. Tank mix with organosilicone or non-ionic surfactant.
• fluxapyroxad plus pyraclostrobin (Priaxor Xemium): 4.0 to 8.0 fl oz/A; PHI 7d (succulent), 21d (dry), REI 12h, Groups 7 & 11. Maximum 2 applications per year.
• mefenoxam (Ridomil Gold XL): Succulent beans ONLY. 0.125 to 0.2 pt/A. PHI 3d, REI 48h, Group 4. Must be tank mixed with high rate of another fungicide registered for downy mildew.
• potassium salts of phosphorous acid  (Fosphite): 1.0 to 3.0 qt/100 gal/A; PHI 0d, REI 4h, Group P07. To avoid phototoxicity do not apply to heat or moisture stressed crops or plants recently treated with copper.
• potassium bicarbonate (PB 133, AKA MilStop SP^OG): 2.5 lb/100 gal; PHI 0d, REI 1h. May be used in greenhouse. See label for small volume applications.
• Pseudomanas chloraphis strain AFS009 (Howler EVO^OM): 2.5 to 7.5 lbs/A. PHI 0d, REI 4h, Group BM 02. Use preventatively. Labeled for various bean varieties. Maybe used in greenhouse - see label.
• pyraclostrobin (Headline): 6.0 to 9.0 fl oz/A; PHI 7d (succulent) to 21d (dry), REI 12h, Group 11. Do not make more than 2 applications before rotating to a non-Group 11 fungicide.

Rhizoctonia solani

Rhizoctonia solani causes stem cankers on peas and beans. The pathogen survives as sclerotia (fungal survival structures) and mycelium in the soil and in plant debris.  It is spread by wind, rain, irrigation water, and movement of infested soil. When a field becomes infested, it remains so indefinitely. Seedlings and young plants are highly susceptible to infection and disease severity is increased by low soil temperatures and compaction. Seed decay and damping off can be controlled by using high-quality seed and with practices that encourage rapid germination and emergence. Soil preparation that minimizes soil compaction and structural damage will lessen disease severity. Rotate crops with a cereal or pasture crop (avoid beets, beans, brassicas and potatoes, all of which increase inoculum). Cover crops and other practices that increase organic matter and improve soil structure are recommended. Some brassica crops (mustard, rape) used as green manure have been reported to be disease suppressive.

• azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 2.4 pt/A; PHI 14d, REI 12h, Group 11 & M05. DRY bean only. Labeled for web blight caused by Rhizoctonia solani.  See label for tank mixing restrictions. 
• Bacillus amyloliquefaciens F727 (Stargus^OG): 1.0 to 4.0 qt/A; PHI 0d, REI 4h, Group BM02. Apply preventatively in a minimum of 50 gallons of water/A.
• fludioxonil (Maxim 4FS): 0.08 to 0.16 oz/100 lb seed; REI 12h, Group 12. For protection against seedborne and soilborne fungi.
• PCNB (Blocker 10G): Bush and pole beans ONLY. 1.0 lbs/1,000 ft. (bush), 1.0-2.0 lbs/1,000ft. (pole); REI 12h, Group 14. For bush and pole beans ONLY. Apply in a 12-15 inch band over seed in-furrow at planting time and cover immediately. Do not feed treated vines to livestock.
• pyraclostrobin (Headline SC): 6.0 to 9.0 fl oz/A; PHI 7d (succulent), 21d (dry), REI 11h. For control of soilborne Rhizoctonia when applied in furrow as a preventive. See label for restrictions. 
• Reynoutria sachalinensis extract (Ragalia^OG): 1.0 to 4.0 qt/A ground application; PHI 0D, REI 4h, Group P05. Apply to ensure thorough coverage. See label for specific application instructions.
• Trichoderma asperellum (ICC 012) plus T. gamsii (ICC 080) (Biotam 2.0): See label for in-furrow, drench, and broadcast rates; PHI 0d, REI 4h, Group BM02.
• thiram (Thiram 42-S): 2.0 fl oz./100lb seed (snap and dry), 3.0 fl. oz/100lb seed (Lima)/100 lb seed; REI 24h, Group M03. labeled for basal stem/stalk rot and seedling blight and damping off - the label DOES NOT mention Rhizoctonia specifically 

Rust (Uromyces appendiculatus)

Appears on the undersides of leaves as small, distinct reddish pustules that produce dust-like spores. Defoliation can occur in severe cases. Plant resistant varieties. Plow under, bury, or otherwise destroy crop residues to reduce overwintering inoculum. Rotate away from beans for 2 years or up to 5 years in reduced tillage systems. Avoid overfertilizing with nitrogen, and ensure adequate potassium. In pole bean production, be sure to disinfect poles. Encourage airflow with adequate plant spacing and avoid overhead irrigation if possible. Irrigate early in the day.

• azoxystrobin (Quadris F): 6.0 to 15.5 fl oz/A; PHI 14d (dry) 0d (succulent) REI 4h, Group 11. For rust, a non-ionic surfactant is advised.
• azoxystrobin plus chlorothalonil (Quadris Opti): 1.6 to 2.4 pt/A; PHI 14d, REI 12h, Groups 11 & M05. DRY bean only. See label for tank mix precautions. Not labeled for soybean. 
• azoxystrobin plus propiconazole (Quilt Xcel): 10.5 to 14 fl oz/A; PHI 7d (succulent), 14 (dry), REI 12h, Groups 11 & 3. May cause crop injury. See label for restrictions and warning.
• Bacillus amyloliquefaciens strain D747 (DoubleNickel 55^OG): 0.25 to 3.0 lb/A (foliar); PHI 0d, REI 4 h, Group BM02. Disease suppression only. For improved control; mix or rotate with a chemical fungicide.
• chlorothalonil (Bravo Weather Stik): 1.375 to 3.0 pt/A (succulent), 1.375 to 2.0 pt/A (dry); PHI 7d (succulent) 14d (dry), REI 12h, Group M05.
• fluxapyroxad plus pyraclostrobin (Priaxor Xemium): 4.0 to 8.0 fl oz/A; PHI 7d (succulent), 21d (dry), REI 12 h, Groups 7 & 11. Maximum 2 applications per year.
• myclobutanil (Rally 40WSP): 4.0 to 5.0 oz/A; PHI 0d, REI 24h, Group 3. Observe a 30-day plant back interval.
• penthiopyrad (Fontelis): 14.0 to 30.0 fl oz/A 14.0 to 20.0 fl oz/A (dried); PHI 0d, REI 12h, Group 7. Maximum 2 applications per year.
• propiconazole (Tilt): 4.0 fl oz/A; PHI 7d (succulent) 0d (dry), REI 12h, Group 3. May cause plant injury in certain bean varieties. See label for restrictions and warnings.
• pyraclostrobin (Headline): 6.0 to 9.0 fl oz/A; PHI 7d (succulent) to 21d (dry), REI 12h, Group 11.  Do not make more than 2 applications per season before rotating with another Group 11 fungicide.
• sulfur (Microthiol Disperss^OG): 3.0 to 10.0 lb/A; PHI 0d, REI 24h, Group M02. See label for restrictions and phytotoxicity warnings. 

Seed Decay

Buy treated seed. Do not use treated seed for food or feed.

• Bacillus amyloliquefaciens strain D747 (DoubleNickel 55^OG): 0.125 to1.0 lb/A at planting; PHI 0d, REI 4 h, Group BM02. Suppression only.
• fludioxonil (Maxim 4FS): 0.08 to 0.16 oz/100 lb seed; REI 12h, Group 12. For protection against seedborne and soilborne fungi.
• mefenoxam (Apron XL): 0.085 to 0.64 fl oz/100 lb seed; REI 48h, Group 4. For Pythium damping off. Early season Phytophthora protection (0.64 fl oz/lb seed). Rate varies with bean type - see label
• Streptomyces griseoviridis strain K61 (MycoStop^OG): see label for rate information; REI 4h, Group BM02. Rates vary by pound of seed to be treated. See label for application instructions and restrictions. 
• thiram (Thiram 42-S): 3.0 fl oz/100lb seed (lima) 2.0.0 fl oz/100lb seed lb (snap & dry); REI 24h, Group M03.

White Mold (Sclerotinia sclerotiorum)

Space plants to allow good air circulation. Plant on well-drained soil. Sclerotinia produces sclerotia, which are hard, black structures that are 1/16" to 1/2" long, inside or on the surface of infected tissue. Sclerotia can survive for years in the soil and are responsible for initiating disease. Sclerotia germination of sclerotia is weather dependent with peak germination at 52°F though some sclerotia germinate over a wider range of temperatures. A minimum of ten consecutive days of available water in soil is also required for germination of sclerotia.

Many vegetable crops and weeds are susceptible to this fungus; corn and grasses are not. Lettuce, cabbage, tomato, carrot, brassicas and snap beans are among the most susceptible and should not be grown on land known to be contaminated with Sclerotinia. After an episode of disease, rotate away from susceptible crops for 7 years. A single infected head of cabbage may produce more than 1,000 sclerotia. Removal of diseased plant material as soon as possible is highly recommended.

• Bacillus amyloliquefaciens strain F727 (Stargus^OG): 1.0 to 4.0 qt/A; PHI 0d, REI 4h, Group BM02. Apply in furrow at planting in a minimum of 5 - 15 gallons of water/A. See label for additional application methods and instructions. 
• boscalid (Endura): 8.0 to 11.0 oz/A; PHI 7d (succulent), 21d (dry), REI 12h, Group 7. Do not make more than 2 applications per season.
• cyprodinil plus fludioxonil (Switch 6.25 WG): 11.0 to 14.0 oz/A; PHI 7d, REI 12h, Groups 9 & 12. Make the first application at 10-20% bloom. In some locations a single application at this timing will provide adequate disease control.
• Coniothyrium minitans Strain CON/M/91-08 (Contans WG^OG): Apply 1.0 to 4.0 lb/A in 20 to 50 gal water; PHI 0d, REI 4h, Group BM02. Spray on the soil surface and incorporate into the top 2" of soil. See label for application instructions and restrictions. Do not tank mix with other fungicides. 
• fluazinam (Omega 500F): 8.0 to 13.6 fl/A; PHI 14d succulent, PHI 30d dry and lima beans, REI 12h, Group 29. Make the first application at 10-30% bloom. See label for restriction applications.
• iprodione (Rovral 4F): 1.5 to 2.0 pt/A; PHI 14d, REI 24h, Group 2.  Limit 2 application per season - last application no later than peak bloom. Thorough coverage is essential. See label for livestock feeding restrictions.
• laminarim (Vacciplant): 14.0 to 22.0 fl oz/A; PHI od, REI 4h, Group P04. See label for application methods and restrictions. 
• penthiopyrad (Fontelis): 16.0 to 30.0 fl oz/A (succulent), 16.0 to 20.0 fl oz/A (dry); PHI 0d (succulent), 21d (dry), REI 12h, Group 7. Maximum 2 applications per year. See label for specific application methods
• thiophanate-methyl (Topsin 4.5 FL): 20 to 30 oz/A; PHI 14d snap or lima and 28d dry, REI 24h (succulent) and 72h (dry), Group 1. Rate is dependent on crop phenology, see label for details.
• Trichoderma asperellum (ICC 012) plus T. gamsii (ICC 080) (Biotam 2.0): See label for in-furrow, drench, and broadcast rates; REI 1h, Group BM02.
• Ulocladium oudemansii (U3 strain) (BotryStop^OG): 2.0 to 4.0 lbs/A; REI 4h, Group BM02. Begin application when conditions are conducive to disease development.

Bacterial Diseases (Pseudomonas spp. and Xanthomonas spp.)

Bacterial leaf diseases include: bacterial bean blight (Xanthomonas campestris pv. phaseoli), bacterial brown spot or rot (Pseudomonas syringae pv. syringae), and halo blight (Pseudomonas syringae pv. phaseolicola). Plant disease-free seed from a reliable supplier. Eliminate wild cherries and lilacs near bean fields. Do not cultivate or harvest when plants are wet. Use a 2-year rotation. Plow under infected debris in fall.

• copper hydroxide (Kocide 3000): 0.5 to 1.25 lb/A; PHI 0d, REI 48h, Group M01. Do not apply with a spray solution having a pH less than 6.5 or tank mix with Aliette. An organic formulation is available. 
• laminarim (Vacciplant): 14.0 to 22.0 fl oz/A; PHI od, REI 4h, Group P04. See label for application methods and restrictions. 
• Reynoutria sachalinensis extract (Regalia^OG): 1.0 to 4.0 qt/A ground application; PHI Od, REI 4h, Group P05. Apply to ensure thorough coverage. See label for specific application methods and instructions.

Bean Common Mosaic Virus (BCMV)

In addition to mosaic and lesions of the foliage, BCMV can also cause blackened roots. Several different strains of the virus are recognized; the symptoms and host ranges vary according to the strain. The virus can be seedborne and is transmitted by at least 12 species of aphids in a nonpersistent manner. Resistant varieties are readily available and constitute the most reliable means of control. Seed treatment, insecticides, and roguing of diseased plants are of little value.

Bean Yellow Mosaic Virus (BYMV)

Many strains of this virus are known. Symptoms of BYMV are easily confused with BCMV. However, BYMV is not seedborne and unlike BCMV, BYMV is spread in a persistent manner by more than 20 species of aphids. Entire plantings may become infected, resulting in substantial yield losses. Disease outbreaks are often correlated with the presence of virus-source plants such as sweet clover, white clover, crimson clover, and Gladiolus sp. Since the virus overwinters in legumes such as clover and vetch, beans should be planted at least 800 ft away from these species. Insecticides applied early will reduce spread. Control weeds. Plant BYMV resistant varieties (see varieties list, page 124).