Fire Blight is a bacterial disease that affects plants in the rose family including; apple, pear, crabapple, hawthorn, cotoneaster, mountain ash, quince, rose, pyracantha, and spirea.
The bacteria overwinters in cankers, which produce a sticky ooze in the early spring. The bacteria is spread from the cankers by insects and by wind-blown rain.
Careless pruning practices may also spread the bacteria.
The blossoms are usually the first to become infected in the spring. The bacteria multiply rapidly in the blossom nectar and infect the blossoms.
The succulent new shoots are also susceptible to bacterial infection. When infected, the tender tips wilt, die and assume a characteristic shepherd’s-crook. These infections often kill a foot or more of the terminal growth. Leaves and shoots turn a rusty brown/black color and the dead leaves remain attached to the dried shoots.
The bacteria can also be spread through the plant’s waterconducting (vascular) system.
How to treat Fire Blight
Ferti-lome Fire Blight Spray is an antibiotic, Streptomycin. This is intended for bacterial issues only. Make the first application at the start of the blossoming period, repeat in 3 to 4 days, then up to two more applications, 5 to 7 days apart. Do not apply when fruit is visible.
NG Copper Soap can be sprayed as a preventer, make one application just prior to bud crack, one application mid to late bloom and one just after blossom drop. Also use after storm damage when fruit are present. Make one or two applications after storm damage when fruit are present.
Can Fire Blight be eliminated by pruning the affected areas?
Yes! You can eliminate the fire blight infection by pruning out diseased branches. Always cut an infected branch at least 8 to 12 inches below the visible injury or canker. In May or June, when blight bacteria is moving rapidly, a greater distance, 12 to 15 inches below infections may be required.
Make sure to sterilize all pruners and saws, between cuts to inhibit spread that way.