Blight
Blight is a rapid and complete chlorosis, browning, then death of plant tissues such as leaves, branches, twigs, or floral organs. Accordingly, many diseases that primarily exhibit this symptom are called blights. Several notable examples are:
Boxwood blight
The blight initially presents as dark or light brown spots or lesions on leaves. The leaves typically turn brown or straw color, then fall off. The stems develop dark brown or black lesions. The disease is often fatal to young plants.