Remove background drawable programmatically in Android

I want to remove the background drawable @drawable/bg programmatically. Is there a way to do that?

Currently, I have the following XML in my layout:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    android:id="@+id/widget29"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:background="@drawable/bg">

</RelativeLayout>