My plant has white growth in the center and on the leaves. How do I treat this?
Fungus diseases rarely are an issue with Ponytail Palm and the presence may indicate over-watering or poor soil drainage.
Excessive water around the roots will cause Root Rot, and the plant may not recover from this.
Water only when the soil has dried out.
This is likely Mealybug and can be treated with Neem Oil.
Here are some links with more information.