If the closing date is not established at the time assent forms are mailed to producers, and the director subsequently finds that because of the oncoming harvesting season or because of any other relevant reason it is desirable to fix a closing date for filing assents, he may do so by publishing a notice pursuant to Section 6061 of the Government Code in the capital of the state and in such other localities as the director may prescribe not less than 10 days prior to the closing date. The closing date shall also be announced by a press release for general dissemination which is issued by the director at least 10 days prior to the closing date.