The Finance Ministry said 23 agricultural commodities, including wheat, barley, chana, Coriander,Cardamom,guar seed,cotton and potato etc. would be exempted from the levy. The tax would be levied on futures trading and not on spot trading in the commodities. Besides gold, silver, crude oil and base metals, processed farm items like sugar, soya oil and guar gum will come under CTT, it said. You can check out Commodity tax implications here.