Crown rot causes rotting of the plant crown and roots followed by wilting of the plant. The disease worse on overwatered plants. There is no control.
Powdery mildew causes a white powdery growth on leaves and blossoms. This problem is worse when plants are subjected to poor air circulation.
Bud drop be due to low temperatures, low humidity, overwatering and extreme fluctuations in soil moisture, temperature or light intensity.