apples in my garden started flowering few days ago but soon it disapears.
I sprinkle some sulpher but couldn't get rid of.
please suggest something to save my apples.

Are the bees visiting the flowers?

I don't really understand the complaint. What's happening to the flowers? Are you having frost at night? This could kill the fruit.

It is normal for the petals to drop off of the flowers, I wouldn't put anything on them that could harm the insect pollinators.