Unfortunately, Photinia x fraseri is susceptible to a number of nasty fungal diseases in addition to fire blight, all of which are very difficult to control. The decline of this plant has reached epidemic proportions throughout its growing range, largely due to it being planted by the millions for hedging. Therein lies the problem: in order to fight off infections, this plant needs excellent air circulation, full sun and good drainage, so growing it in tight groups as a hedge (and fungi love close, dark conditions) is a setup for disaster. Rather than struggle with constant chemical treatments, most people are opting to rip out their red tip hedges and replace them with other plants.
Suggestion: one of the hybrid parents of red tip photinia is Chinese photinia (Photinia serrulata), which has a much greater resistance to fungal diseases. It is larger in stature, reaching 15-25 feet tall or higher, with large, glossy, evergreen leaves whose new growth is bronzy-pink vs. the bright red of its hybrid progeny – maybe not as striking but very attractive. In early spring it produces 8- to 10-inch-wide clusters of small white flowers that are followed by hanging, clustered orange-red berries in the winter. It can be planted and clipped as a large hedge but is most spectacular when trained as a small specimen tree. There is a dazzling new variegated variety called “Pink Crispy” available in Europe but not yet in the U.S.–I am greatly looking forward to its arrival!