The present invention discloses a spreader (100, 200, 300) having an adjustment mechanism (160) for controlling a rate of discharge through the material dispensing hole (158). The adjustment mechanism (160) including an adjustment element (162) slidably mounted on a bucket (102, 202, 302) and disposed over the material dispensing hole (158), wherein a movement of the adjustment element (162) is configured to vary a degree of opening of the material dispensing hole (158) between a full open position and a full closed position. A linking element (184, 284, 384) having a first end (186) and a second end (188), the first end (186) of the linking element (184, 284, 384) is attached to the adjustment element (162) and a manually actuable lever (170, 270, 370) having an attachment portion (176, 276, 376) to support the second end (188) of the linking element (184, 284, 384). The attachment portion (176, 276, 376) of the manually actuable lever (170, 270, 370) have a circular arc profile with a geometric centre at a point of support (P) of the linking element (184, 284, 384) with the bucket (102, 202, 302), and the second end (188) of the linking element (184, 284, 384) is movable along the attachment portion (176, 276, 376).