Fire Blight

Apple Fire Blight   Branch Fire Blight   Pear Fire Blight  Fire Blight

Fire blight
, caused by the bacterium Erwinia amylovora, it is a serious disease that affects new leaves, fruit, flowers, and stems of over 75 species of trees and shrubs in the rose family including: apple, crabapple, hawthorn, pear, pyracantha, cotoneaster, spirea, flowering quince, and mountain-ash. Temperature, humidity, insect vectors, and wounding can all affect the severity of infection. If not controlled, it can cause flower and fruit blight, twig and branch dieback, or even kill the plant.

In spring, branch and trunk canker symptoms can appear as soon as trees begin active growth. The first sign is a watery, light tan bacterial ooze that exudes from cankers (small to large areas of dead bark that the pathogen killed during previous seasons) on branches, twigs, or trunks. The ooze turns dark after exposure to air, leaving streaks on branches or trunks. However, most cankers are small and inconspicuous; thus infections might not be noticed until later in spring when flowers, shoots, and/or young fruit shrivel and blacken. The amount of fruit loss depends upon the extent and severity of the disease.

Injuries on tender young leaves and shoots, caused by wind, hail, or insect punctures, are easily invaded by the fire blight bacteria. Such infections lead to shoot blight. Ideal conditions for infection, disease development, and spread of the pathogen are rainy or humid weather with daytime temperatures from 75° to 85°F, especially when night temperatures stay above 55°F.

Fire blight bacteria generally don’t move uniformly through the bark but invade healthy wood by moving in narrow paths up to 1 1⁄2 inches wide in the outer bark ahead of the main infection. These long, narrow infections can extend 2 to 3 feet beyond the edge of the main infection or canker. If you expose bark from an infected woody area, you will see that the diseased tissue closest to the main canker is brown. Farther out, the infection turns red and then appears as flecking. Just beyond the visible infection the tissue will look healthy.

Fire blight development is influenced primarily by seasonal weather. When temperatures of 75° to 85°F are accompanied by intermittent rain or hail, conditions are ideal for disease development. The succulent tissue of rapidly growing trees is especially vulnerable; thus excess nitrogen fertilization and heavy pruning, which promote such growth, should be avoided. Trees shouldn’t be irrigated during bloom. Monitor trees regularly, and remove and destroy fire blight infections. (See Removing Diseased Wood.) If fire blight has been a problem in the past, apply blossom sprays. Sprays prevent new infections but won’t eliminate wood infections; these must be pruned out. In years when weather conditions are very conducive to fire blight development, it can be difficult if not impossible to control the disease.

is an antibiotic that is acceptable for use to protect trees but may be difficult to obtain. Do not use streptomycin after symptom development since it may lead to antibiotic resistance in the bacterial population.

Aluminum tris
is a bactericide used prior to and during bloom.

Copper sprays
are toxic to many species of bacteria. Copper sprays are best used during dormancy and prior to bud break because they may damage leaves and young fruit. Do not apply sprays within 50 days of apple harvest or within 30 days of pear harvest. Do not mix with oils or phytotoxicity issues can occur. Copper is available in several forms and sold under various trade names, including Bordeaux mixture.

is a plant growth regulator that reduces longitudinal shoot growth by inhibiting gibberellin biosynthesis. Prohexadione-calcium does not possess antibacterial activity but alters host biochemistry and tissues in ways that are not favorable for infection by E. amylovora. The length of time that shoot growth is inhibited depends on the application rate and tree vigor. Prohexadione-calcium is ineffective for control of the blossom blight phase of fire blight.

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Agri-Mycin 17 Agricutural Streptomycin, Nufarm

Agri-Mycin 17 Agricutural Streptomycin is a protectant bactericide designed to combat difficult diseases such as fire blight in apples, pears, tomatoes, peppers, celery and tobacco. Agri-Mycin is compatible with most pesticides and offers 3-4 days of dependable protection when applied correctly.

Active Ingredient: Streptomycin Sulfate 22.4%


Product is Discontinued This product has been discontinued by the manufacturer. Consider using Agri-Mycin 50

Aliette WDG Fungicide, Bayer

Aliette Fungicide delivers true, two-way systemic protection against Phytophthora, downy mildew and other diseases. With multiple modes of action, Aliette attacks pathogens at multiple growth stages for better overall disease control.

Active Ingredients: Aluminum tris 80.0 %
Fungicide Mode of Action: P 07
Application Rate Range: (see label)
Container Size(s): 5 Lb.
From $86.95

Cueva Copper Fungicide Concentrate, OMRI Listed, Certis USA

Cueva Copper Fungicide Concentrate is a patented, fixed copper fungicide made by combining a soluble copper fertilizer with a fatty acid to form a true soap. This copper soap fungicide protects plants from infection from a wide range of diseases, including downy and powdery mildews.

Organic Certification(s): OMRI
Active Ingredients: Copper Octanoate (Copper Soap) 10.0%
Fungicide Mode of Action: M 01
Application Rate Range: (see label)
Container Size(s): 2.5 Gal.
From $115.95

Double Nickel 55 Biofungicide, OMRI Listed, Certis U.S.A.

Double Nickel 55 Biofungicide is a new generation fungicide and bactericide for control of foliar diseases. For use on fruit and vegetable crops, Double Nickel 55 Biofungicide employs 5 modes of actions, all working in synchronicity.

Organic Certification(s): OMRI
Active Ingredients: Bacillus Amyloliquefaciens Strain D747 25.0%
Fungicide Mode of Action: BM 02
Application Rate Range: (see label)
Container Size(s): 5 Lb.
From $138.95

Double Nickel LC Biofungicide, OMRI Listed, Certis USA

Double Nickel LC Biofungicide, A new generation fungicide and bacteriacide for control of foliar and soil-borne diseases. Double Nickel LC employs five modes of action. provides excellent control at low rates, has no resistance or residue issues and offers fast worker reentry.

Organic Certification(s): OMRI
Active Ingredients: Bacillus Amyloliquefaciens Strain D747 98.85%
Fungicide Mode of Action: BM 02
Application Rate Range: (see label)
Container Size(s): 2.5 Gal.
From $162.95

Oxidate 2.0 Fungicide Bactericide, OMRI Listed, BioSafe Systems

Oxidate 2.0 Fungicide Bactericide kills bacterial and fungal pathogens, offering superior protection for your organic or conventional field and row crops. Use OxiDate 2.0 for curative and preventative crop protection applications.

Certification(s): OMRI
Active Ingredients: Hydrogen Dioxide 27.1% + Peroxyacetic Acid 2.0%
Application Rate Range: (see label)
Container Size(s): 2.5 Gal., 30 Gal., 55 Gal., 275 Gal.

US DOT Hazmat ALL SALES ARE FINAL. No refunds, returns, or exchanges. This product has been classified by the US DOT as a hazardous material. Adult signature required at time of delivery.

From $74.95

Regalia PTO Biofungicide, OMRI Listed, Marrone Bio Innovations

Regalia PTO Biofungicide Controls bacterial and fungal diseases on many species of turf and ornamentals. Regalia PTO is rainfast in 1 hour so you can get important sprays out even in tough weather. Regalia strengthens plant immune systems. OMRI Listed.

Active Ingredient: Extract of Reynoutria sachalinensis 5%


Reliant Systemic Fungicide, Quest

Reliant Systemic Fungicide is the same as Agri-fos and provides effective treatment for SOD Sudden Oak Death along with various diseases in Ornamentals, Bedding Plants and Turf.

Active Ingredients: Mono- and di-potassium salts of Phophorous Acid 45.8%
Fungicide Mode of Action: 33
Fungicide Class: Phosphite
Application Rate Range: (see label)
Container Size(s): 1 Qt., 1 Gal., 2.5 Gal., Bulk
From $14.95

Mycoshield Fungicide, Nufarm

Mycoshield is a valuable tool to fruit disease management programs. It is used to control fire blight in apples and pears and bacterial spot in peaches and nectarines.

Active Ingredient: Oxytetracycline calcium complex 31.5%

Signal Word - WARNING / AVISO
From $50.95

Tree Tech, Microinjection Antibiotics

The Tree Tech Microinjection OTC (Oxytetracycline) An effective oxytetracycline antibiotic for the control of bacterial and mycoplasma-related diseases such as fire blight, bacterial leaf scorch, X-disease, elm/ash yellows, elm phloem necrosis and lethal yellows of palm. The Tree Tech microinjection system continues to gain acceptance and wider use.

Active Ingredient: Oxytetracycline Calcium Complex 4.57%


Ships From Manufacturer This product is drop-shipped by the manufacturer and will be shipped UPS Ground regardless of method chosen at checkout.

From $4.95

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