A system for guiding a vehicle, the system comprising: a first arm for pivoting about a first pivot point associated with a sprayer implement in response to contact with a first row of plants; a first sensor associated with the first arm to provide a first sensor signal response indicative of a first position or first movement of the first arm with respect to the first row; a second arm for pivoting about a second pivot point associated with the sprayer implement, in response to contact with the first row, or second row of plants spaced apart from the first row with a substantially parallel spacing; and a second sensor associated with the second arm to provide a second sensor signal response indicative of a second position or second movement of the second arm with respect to the first row, or second row; characterized in that a data processor is configured for estimating a series of center points between the first row and the-second row based on targeting substantial symmetry in the first sensor signal response and the second sensor signal response as an indication that a longitudinal axis of the vehicle is aligned with the center point, where substantial symmetry is present if an error or difference between the first sensor signal response and the second sensor signal response is less than a threshold for each estimated center point in the series of center points; that a nozzle (73, 75) associated with the sprayer implement has a nozzle position with respect to a corresponding center point between the rows of plants; and that an offset module for lateral shifting a nozzle position from each center point to a corresponding offset lateral position is provided such that a spray pattern of the nozzle (73, 75) is directed toward target strip of soil or ground around or containing a plant stem of the plants in the row. a first arm for pivoting about a first pivot point associated with a sprayer implement in response to contact with a first row of plants; a first sensor associated with the first arm to provide a first sensor signal response indicative of a first position or first movement of the first arm with respect to the first row; a second arm for pivoting about a second pivot point associated with the sprayer implement, in response to contact with the first row, or second row of plants spaced apart from the first row with a substantially parallel spacing; and a second sensor associated with the second arm to provide a second sensor signal response indicative of a second position or second movement of the second arm with respect to the first row, or second row; characterized in that a data processor is configured for estimating a series of center points between the first row and the-second row based on targeting substantial symmetry in the first sensor signal response and the second sensor signal response as an indication that a longitudinal axis of the vehicle is aligned with the center point, where substantial symmetry is present if an error or difference between the first sensor signal response and the second sensor signal response is less than a threshold for each estimated center point in the series of center points; that a nozzle (73, 75) associated with the sprayer implement has a nozzle position with respect to a corresponding center point between the rows of plants; and that an offset module for lateral shifting a nozzle position from each center point to a corresponding offset lateral position is provided such that a spray pattern of the nozzle (73, 75) is directed toward target strip of soil or ground around or containing a plant stem of the plants in the row.