Peel the radish and cut into wafer-thin slices. Put in a bowl and sprinkle with salt. Mix well and let steep for 10 minutes.
Peel the apple and cut into small pieces. Peel the cucumber and cut into thin slices.
Pour off the water from the salted radish slices. Add apple and cucumber slices to the radish. Add yogurt, cream and dill and season with salt and pepper and a little sugar. Mix everything well.