The councils and commodity programs heretofore created and established under chapter 47 (C. 54:47A-1 et seq.) and chapter 169 (C. 54:47B-1 et seq.) of the laws of 1957 and chapter 18 (C. 54:47C-1 et seq.) and chapter 80 (C. 54:47D-1 et seq.) of the laws of 1959 shall be subject to the provisions of section 15 of this act.
The councils under said chapters may alter the assessment rates prescribed therein and the form and manner of the assessment prescribed with respect thereto, in the same manner as provided in section 17 of this act.