Customs exemption for vegetable products limits duty liability on imports, capping excess duty to a prescribed ad valorem rate. The Central Government, invoking section 25(1) of the Customs Act, 1962, exempts imports of vegetable products falling within Chapter 14 from customs duty to the extent that such duty exceeds the amount computed at a specified ad valorem rate, thereby capping the recoverable duty on those imported goods under the Customs Tariff Act.