Deductibility timing for additional sugarcane price: deduction when liability arises; self grown cane valued and deducted when utilised. Additional price payable to sugarcane cultivators is deductible in the year the additional liability arises for market purchases, while for self grown sugarcane the market value is deductible in the year it is utilised as raw material; revisions of price are referable to the year of utilisation. Procedural remedies include filing a revised return, presenting claims in appeal, applying for administrative revision after completion of assessment, and invoking hardship relief where appropriate.