(i)it has begun or begins to manufacture or produce articles after the 31st day of December, 1970 ][but before the 1st day of April, 1990] [ Inserted by Act 12 of 1990, Section 20 (w.e.f. 1.4.1990).][, in any backward area; [Inserted by Act 26 of 1974, Section 9 (w.e.f. 1.4.1974).]