Tag Viva is a combination herbicide containing two different technical to provide better control. The chemical composition of Tag Viva is penoxsulam 1.02 % and Cyhalofop-butyl 5.1 % OD. It is a systemic weedicide. Once you apply this product in your rice fields, the weeds uptakes the chemical. Once the technical enters the plant body, It inhibits two plant enzymes which are essential for growth.