Stem canker causes cankers at the base of the stem. The roots decay as the disease progresses.
Chlorosis may be due to iron deficiency or overwatering.
Manganese and aluminum salts sometimes cause leaf scorch. One half inch of the leaf tips yellow then turn brown. Adding lime will reduce the browning.
Bud blast, is the drying up and failure of flower buds to open. Possible causes are root injury, cold soil, high temperatures during cloudy weather, and excessive shading.
The lower leaves drop if the plant receives insufficient light.