Ala. Code § 17-13-19
In the event either of the two candidates receiving the highest number of votes in the first primary election shall determine not to enter the second primary election provided for in this chapter, the candidate, as soon as possible and not more than three days after holding of the first primary election, shall certify his or her declination to enter such second primary election to the chair of the state executive committee of his or her party, if the office is an office other than a county office, or to the chair of the county executive committee of his or her party if the office is a county office. Upon the receipt of such notification, the chair of such committee shall declare the other candidate the nominee of the party for such office and certify his or her name as such nominee to the Secretary of State or the judge of probate, as the case may require, and a second primary election for the nomination of a candidate for that particular office shall not be held.
Ala. Code § 17-13-19 (1975)