Section 8B of the Assam Agricultural Income-tax (Amendment) Act, 2009 came into force on 1 April 2009. The Court held that the law applicable for assessment is the law in force during the relevant assessment year unless the amendment is expressly or by necessary implication retrospective. Since section 8B became effective from 1 April 2009, it applied to agricultural income for the financial year 2008-09 corresponding to A.Y. 2009-10. The Court accordingly upheld the applicability of section 8B to the assessment of agricultural income for that year. (AY. 2009 10)