Dandruff is caused when a fungus called malassezia grows on your scalp this result in shedding of the scalp, skin. There are two types of dandruff.
One occurs due to the dryness of the scalp, while the other occurs due to the excessive production of oil on the scalp.
Just massage 2 tablespoons lemon juice into your scalp and rinse with water. Then stir 1 teaspoon lemon juice in 1 cup water and rinse your hair with it. Repeat this daily until your dandruff disappears