The question of the spray volume for applying agrochemicals to plants has and still demands studies to continuously search for guiding parameters for technicians due to the several variables involving application technology. This experiment aimed to determine the best spray volume for applying pesticides with a boom sprayer to soybean (Glycine max) and wheat (Triticum aestivum) crops. The experiment had a completely randomized blocks design with five treatments and five replications. In soybean (crop year 2011/12), the treatments were the control (no pesticide application) and spray volume applications of 50, 100, 150, and 200 L ha-1. For wheat (crop year 2012), the treatments were the control and spray volumes of 75, 100, 125, and 150 L ha-1. The variables analyzed were the yield components. The study concluded the need for applying foliar fertilizers and performing the chemical control of diseases and pests in soybean and wheat crops. The spray volumes of 50 L ha-1 for soybeans and 75 L ha-1 for wheat were satisfactory for spraying agrochemicals with a ground bar sprayer on plants.