· Brent Wilson's Answer
· Hi Vickie - If the ends of branches and the leaves on them are turning black this is most likely fire blight. To be sure, you could upload a picture of the tree and a closeup up the affected parts so I can positively identify it.
If it is fire blight, unfortunately, this is one of the most devastating and difficult-to-control diseases on apple trees, other fruit trees, and members of the rosaceae plant family, such as quince. It is caused by a bacteria and can spread rapidly if not controlled. Even when steps are taken to control the disease it can still kill trees.
When fire blight is present, infected flowers turn black and die. Then the disease moves down the branch, resulting in death of young twigs, which blacken and curl over. Leaves on affected branches wilt, blacken and remain attached to the plant, giving it a fire-scorched appearance. Slightly sunken areas, called cankers, appear on branches and the main stem.
If you catch fire blight soon enough, you can reduce the spread of it by removing and destroying all infected plant parts. Pruning cuts should be made 12 to18 inches below any sign of infected tissue. Regarding a young tree, and depending on how far the fire blight has spread, this might mean removing much of it's branches/ branch system. Between each pruning cut, dip you pruners in a solution of 1 part bleach to 9 parts water to disinfect them.
Here's some other things you can do to try to prevent fire blight:
Avoid quick-release fertilizers that are high in nitrogen.
Insects can spread the bacteria so try to control them, but don't use insecticides during the bloom phase because this can kill pollinating insects. No pollinators, no fruit.
Streptomycin is a bactericide that can be used on apple trees to prevent fire blight. When using this or any other chemical, make sure to read label for application instructions.
Hope this information was helpful. Don't hesitate to ask if you have any further questions. To upload a picture to this question click on the Upload A Picture link to the right of your name above.