Income from the manufacture of rubber.

7A.    (1) Income derived from the sale of centrifuged latex or cenex  or latex based crepes (such as pale latex crepe) or brown crepes (such as estate brown crepe, remilled crepe, smoked blanket crepe or flat bark crepe) or technically specified block rubbers manufactured or processed from field latex or coagulum obtained from rubber plants grown by the seller in India shall be computed as if it were income derived from business, and thirty-five per cent of such income shall be deemed to be income liable to tax.

         (2) In computing such income, an allowance shall be made in respect of the cost of planting rubber plants in replacement of plants that have died or become permanently useless in an area already planted, if such area has not previously been abandoned, and for the purpose of determining such cost, no deduction shall be made in respect of the amount of any subsidy which, under the provisions of clause (31) of section 10, is not includible in the total income.