No,  I suspect the soil is just showing a build up of salts from fertilizer and warm weather. If the plant is fine there is nothing to worry about. This is very common. You should try to flush the salts from the soil by watering deeply once a month or so. When you water just a little more frequently the salts rise to the surface. Using a slow release plant food like Osmocote will help with this problem as the fertilizer is released so slowly. Keep growing, Marianne Binetti