Fruit Crops Blueberries
Diseases of Blueberries and Fungicides Labeled for Control
Disease Fungicidesa Efficacyb
Mummy Berry (Monilinia vaccinii‐corymbosi) Abound, Heritage (azoxystrobin) ++ Bravo, etc. (chlorothalonil) Symptoms: This fungus attacks and kills leaves, twigs, Bumper, Orbit, Propimax, Tilt leaves, flowers and fruit. Infected fruit turn cream to (propiconazole) pink as they begin to mature and then shrivel and Captan, Captec (captan) + harden into “mummies.” Captevate (captan + fenhexamid) ++ Source of Inoculum: The fungus survives in the Indar (fenbuconazole) +++++ mummified fruit. Spores are wind‐dispersed. Pristine (boscalid + pyraclostrobin) ++++ Control: Remove or bury mummified fruit. Follow the Quilt Xcel (azoxystrobin + fungicide spray schedule. propiconazole) Switch (cyprodinil + fludioxonil) ++ Ziram (ziram) +
Botrytis Blight (Botrytis cinerea) Captan, Captec (captan) ++ Symptoms: This fungus attacks tender young twigs, Captevate (captan + fenhexamid) +++++ leaves, flowers and fruit, causing them to become Elevate (fenhexamide) +++++ brown to black. Infected fruit do not rot until after Iprodione (iprodione) harvest. Pristine (boscalid + pyraclostrobin) +++++ Source of Inoculum: The fungus survives as dormant Switch (cyprodinil + fludioxonil) +++++ mycelium or sclerotia, and the spores are wind‐ Ziram (ziram) ++ dispersed. Control: Follow the fungicide spray schedule.
Phytophthora Root Rot (Phytophthora cinnamomi)
Symptoms: Initially, leaves become yellow and plant growth ceases. Rootlets will be killed, and infected Aliette, Legion (aluminum tris) +++ roots and crowns will be discolored. Bushes may Ridomil (mefenoxam) +++ defoliate and die. Fosphite, Fungi‐Phite, Helena +++ Source of Inoculum: The pathogen survives as Prophyt, pHorcepHite, Phostrol, chlamydospores in the soil. Disease development is Rampart (phosphite) favored by wet soil conditions. MetaStar (metalaxyl) Control: Plant disease‐free plants in well‐drained soil or raised beds. Use the appropriate fungicides.
Fruit Rots (Alternaria, Colletotrichum, Phomopsis) Abound, Heritage (azoxystrobin) +++++ (including Anthracnose Fruit Rot or Ripe Rot) Aliette, Legion (aluminum tris) sc Cabrio (pyraclostrobin) ++++ Symptoms: A variety of rots develop on the fruit as Captan (captan) +++ they mature. Indar (fenbuconazole) Source of Inoculum: The fungi causing fruit rots Kocide, etc. (copper hydroxide) survive from year to year on or in infected tissues. Quilt Xcel (azoxystrobin + Control: Follow the fungicide spray schedule. propiconazole) Pristine (boscalid + pyraclostrobin) +++++ Switch (cyprodinil + fludioxonil) +++++ Fruit Crops Blueberries
Disease Fungicidesa Efficacyb
Ziram (ziram) +++
Leaf Spot (Septoria) Abound, Heritage (azoxystrobin) ++++ Symptoms: Small, circular, light‐colored lesions with a Bravo, etc. (chlorothalonil) ++++ purple border are produced on leaves, and sunken Bumper, Orbit, Propimax, Tilt lesions may be formed on stems. (propiconazole) Source of Inoculum: The fungus survives from year to Cabrio (pyraclostrobin) ++++ year in infected leaf debris and stem lesions. Spores Indar (fenbuconazole) ++++ are wind‐borne. Pristine (boscalid + pyraclostrobin) +++++ Control: Follow the fungicide spray schedule. Quilt Xcel (azoxystrobin + propiconazole)
Stem Cankers and Blights (Botryosphaeria, Phomopsis) Abound, Heritage (azoxystrobin) ++ Aliette, Legion (aluminum tris) s Symptoms: Brownish cankers form on stems, Cabrio (pyraclostrobin) +++ resulting in branch dieback. Indar (fenbuconazole) Source of Inoculum: The pathogen survives from year Pristine (boscalid + pyraclostrobin) +++ to year in infected stems. Spores are rain‐splashed. Quilt Xcel (azoxystrobin + Control: Follow the fungicide spray schedule. propiconazole) Ziram (ziram) +++
Bacterial Leaf Scorch and Decline (Xylella fastidiosa) Symptoms: The initial symptom is a scorching (burning) of the margins of the leaves, which may be limited to individual branches. Leaves may drop prematurely, and developing fruit may suddenly shrivel. New growth in the spring may look chlorotic, with reddish‐purple spotting or discoloration of the leaf margins. Plant will grow slowly and become stunted. Infected plants eventually will die. Source of Inoculum: The pathogen survives from year to year in infected bushes and various alternate hosts. This bacterium is vectored by sharpshooter leafhoppers and other xylem‐feeding insects. Control: Use only disease‐free transplants. Remove infected plants as soon as they are detected. Use insecticides to control the vectors. a Trade name (chemical name) b Efficacy ratings are on a 1‐5 scale where 5 (+++++) is the most effective and 1 (+) is the least effective. Ratings are taken from the 2007 Southeast Regional Blueberry Integrated Management Guide of the Southern Region Small Fruit Consortium (http://www.smallfruits.org/SmallFruitsRegGuide/index.htm) c For disease suppression only.
Fruit Crops Blueberries
Fungicide Spray Schedule for Blueberries
Season Timing Disease(s)
Early Spring Before initiation of root growth Phytophthora root rot
Green tip (or when 1‐5% of blooms Mummy berry are open, whichever comes first) (shoot blight phase) Pre‐bloom 7‐14 days later Mummy berry and twig blight
Mummy berry, twig blight, Botrytis 10‐20% bloom blight and fruit rots Bloom Mummy berry, twig blight, Botrytis Full bloom blight and fruit rots
Immediately after bloom Fruit rots
Petal fall 10‐14 days later Fruit rots
10‐14 days later Fruit rots
Pre‐harvest Fruit rots Summer After Harvest Leaf spots
After harvest Leaf spots and bacterial canker Fall 4 weeks later Bacterial canker
Fruit Crops Blueberries
Fungicides Labeled for Use on Blueberries
Common Trade Rate(s) FRAC PHI Formulation(s) Comments Name Name(s) (per Acre) Group (days)
aluminum tris Aliette 80 WDG 5 pounds 14‐ to 21‐day interval; no 33 0.5 (O‐ethyl Legion more than four applications phosphonate) or 20 pounds per acre per season; do not mix with copper fungicides
azoxystrobin Abound, 2.08 L 6.2‐15.4 7‐ to 14‐day interval; no 11 0 Heritage 50 W fluid more than two sequential ounces applications; no more than 3.2‐8 1.44 quarts or 1.5 pounds ounces per acre per season azoxystrobin + Quilt Xcel 1.18 + 1.02 L 14‐21 fluid See label; no more than 11 + 3 30 propiconazole ounces two consecutive applications; no more than 82 fluid ounces per acre per season
boscalid + Pristine 38 WDG 18.5‐23 7‐ to 14‐day interval; no 7 + 11 0 pyraclostrobin ounces more than two sequential applications; no more than 115 ounces per acre per season
captan Captan, 50 W 5 pounds 7‐day interval through M4 1 Captec 80 WDG 3.125 bloom then 7‐ to 10‐day 4L pounds interval; no more than 70 2.5 quarts pounds, 43.75 pounds or 35 (0.75‐1 quarts per acre per year, quarts/100 respectively gallons)
captan + Captevate 68 WDG 3.5‐4.7 7‐ to 10‐day interval; no M4 + 17 0 fenhexamid pounds more than two consecutive applications; no more than 21 pounds per acre per season
chlorothalonil Bravo, 38.5% F 4.25‐5.75 10‐day interval (10‐ to 14‐ M5 42 Chloronil, 54% F pints day interval after harvest); Chlorothalonil, 82.4% WDG 3‐4 pints no more than 17 pints, 12 Echo, 2.7‐3.6 pints or 10.9 pounds per Equus, pounds acre per season; do not Initiate apply after early to full bloom until after harvest Fruit Crops Blueberries
Common Trade Rate(s) FRAC PHI Formulation(s) Comments Name Name(s) (per Acre) Group (days)
copper Champ, Metallic copper M1 NA hydroxide Kocide equivalent 24.4% 2.67‐5.33 For bacterial canker, apply 30% pints before fall rains and again 35% 1.75‐3.5 four weeks later 37.5% pounds 50% 3‐6 pounds ‐‐‐‐‐‐‐‐‐ 3.75‐4.67 ‐‐‐‐‐‐‐‐‐ 24.4% pounds For Phomopsis twig blight, 30% 4‐8 pounds apply in early spring as a 35% ‐‐‐‐‐‐‐‐‐ dormant spray beginning at 4 pints bud swell and at 10‐ to 14‐ 1‐2.25 day interval during pre‐ pounds bloom; 2‐4 pounds Do not use in spray solution with pH less than 6.5
copper Badge X2 Metallic copper See label. M1 2 hydroxide + equivalent copper 28% 1.75‐3.5 For bacterial canker, apply oxychloride pounds before fall rains and again four weeks later; For fruit rot and Phomopsis 1.0‐2.25 twig blight, begin pounds applications when bloom buds begin to swell; then at 10‐ to 14‐day intervals before blooms open copper sulfate, Cuprofix Metallic copper For bacterial canker, apply M1 0.5 basic equivalent before fall rains and again 40% 3‐4 pounds four weeks later; for
/ 2‐4 Phomopsis twig blight, pounds apply in early spring as a dormant spray beginning at bud swell and at 10‐ to 14‐ day interval during pre‐ bloom; do not use in spray solution with pH less than 6.5
cyprodinil + Switch 62.5WG 11‐14 7‐ to 10‐day interval; no 9 + 12 0 fludioxonil ounces more than two consecutive applications; no more than 56 ounces per crop Fruit Crops Blueberries
Common Trade Rate(s) FRAC PHI Formulation(s) Comments Name Name(s) (per Acre) Group (days)
cuprous oxide Nordox Metallic copper For bacterial canker, apply M1 1 equivalent with a spreader‐sticker 50.1% 10‐15 before fall rains and again pounds four weeks later; for Phomopsis cane canker, apply with a spreader‐ sticker before fall rains and again four weeks later; in the spring during wet weather, apply at 10‐ to 14‐ day intervals beginning at leaf emergence fenbuconazole Indar 2F 6 fluid 8‐ to 14‐day interval; no 3 30 75 WSP ounces more than four applications 2 ounces or 24 fluid ounces or 8 ounces per acre per year, respectively
fenhexamid Elevate 50 WDG 1.5 pounds 7‐day interval; no more 17 0 than two consecutive applications; no more than 6 pounds per acre per season
iprodione Iprodione 4 L 1‐2 pints 14‐day interval with 2 0 maximum of four applications per season;
mefenoxam Ridomil, 4 EC 3.6 pints No more than two 4 0 Ultra Flourish 4 SL applications per season applied as soil sprays (3 foot band)
metalaxyl MetaStar 2 E 14.5 pints See label. No more than 4 ‐ two applications per season applied as soil sprays (3 foot band)
phosphite Fosphite, Phosphorous acid 7‐ to 14‐day interval; see 33 0 (phosphorous Fungi‐phite, equivalent (lb/gal) label for specifics acid salts) Helena Prophyt, 3.38 1‐2 quarts pHorcepHite, 3.9 1‐3 quarts Phostrol, 4.2 4 pints Rampart 4.32 2.5‐5 pints
propiconazole Bumper, 41.8 EC 6 fluid 7‐ to 10‐day interval from 3 30 Orbit, ounces green tip through petal fall; Fruit Crops Blueberries
Common Trade Rate(s) FRAC PHI Formulation(s) Comments Name Name(s) (per Acre) Group (days)
Propimax, no more than 30 fluid Tilt ounces per acre per season pyraclostrobin Cabrio 20 EG 14 ounces 7‐ to 14‐day interval; no 11 0 more than two sequential applications; no more than 56 ounces per acre per season
sulfur Microfine 80% 6‐15 Do not use when hot or M2 1 Sulfur, 90% pounds when temperatures are Microthiol 10‐30 expected to be above 90 Disperss, pounds degrees F over the next Yellow Jacket three days; do not use Wettable within two weeks of an oil Sulfur spray; see label for application intervals
ziram Ziram 76 DF 3 pounds Apply at green tip and M3 14 seven days later; do not apply later than three weeks after full bloom