Keith Collins is the LSU AgCenter county agent for Richland Parish. This news article originally appeared in The Richland Beacon News on February 24, 2011.
Fire blight is a bacterial disease
destructive to many varieties of apples and pears but may also damage ornamental plants such as the Bradford Pear
. Infection normally occurs during the bloom period followed by infection on leaves, twigs and stems, which turn brown and black, giving it a scorched appearance; hence the name "fire blight
." The year 2011 has been particularly bad due to ideal conditions for infection during the blooming period. There are many infected trees throughout Lincoln Parish.
Once the tree is infected, control measures are limited. However, fire blight spread within trees can be reduced by applications of "fire blight spray" that include streptomycin or copper. Copper is the most readily available at local garden centers.
Sanitation may be beneficial as well by removing infected leaves, twigs and stems and cutting back 3-4 inches beyond the infection then totally removing and discarding debris from the vicinity.
Ideal control measures begin with three applications of "fire blight spray" in late winter or early spring when Bradford Pears start blooming. The first application should be done when the tree has 5 percent blooms, the second at 25-30 percent blooms and the third at 50-60 percent blooms. These applications will help prevent the spread of the disease that may be present during bloom.
Rapidly growing, succulent twigs are most susceptible to fire blight bacteria. Excessive nitrogen fertilizer promotes this type growth so it is best to use a well balanced fertilizer
with fairly low nitrogen for moderate growth if on a fertilizer program for Bradford Pears.
Contact the Extension office in Rayville at 318-728-3216 for further or related information.