No dealer shall collect any amount, by way of tax, from a person who sells agricultural or horticultural produce grown by himself or grown on any land in which he has an interest, whether as owner, usufructuary mortgagee, tenant or otherwise, when such produce is sold in the form in which it was produced, without being subjected to any physical, chemical or other process for being made fit for consumption save mere dehusking, cleaning, grading or sorting.