A product reservoir is provided that includes a flexible bag and a carton to receive and retain the flexible bag. The bag may contain liquid chemical substances that are dispensed from the bag through a bag spout. The product reservoir may serve as a component to a fluid delivery system, such as a direct injection system employed by agricultural seed planting machines. When the bag is connected to the direct injection system, the liquid substance is placed in fluid communication with a delivery device whereby the substance can be dispensed to a selected area for treatment. The liquid substance may be mixed in-line with water received from a water reservoir prior to being dispensed by the delivery device. The planting machine may be equipped with a plurality of product reservoirs. A method of applying a liquid pesticide to a selected area is also provided.
