Weed control in the growing wheat crop is the essential first step in adding a summer crop to the WF rotation. A residual herbicide applied in the growing wheat will result in weed free conditions until after harvest. Weeds in the maturing wheat crop use the valuable moisture that we receive from summer rains. After wheat harvest, the greatest weed problems are usually kochia, sunflower, and volunteer wheat. Uncontrolled, these weeds will use all of the rainfall received, and crops will enter winter with a dry soil profile. Three to five inches of water can be stored between wheat harvest and fall freeze up in weed free wheat stubble using no-till management. Each tillage operation to control weeds causes reductions in soil moisture. This can be as much as 0.5 inches per tillage operation if the surface soil is moist (Table 4.4), especially during the hot summer months following wheat harvest.