Individual field operations such as ploughing, clod breaking, stubble clearance and leveling are necessary for the preparation of even and fine seed bed. These operations consume time and labor which become more economical. Strip tillage, direct paddy sowing, Zero tillage, requires minimum soil manipulation and no tillage respectively, where there incur reduced cost of operation. Timely sowing and proper weed control results in bringing out good returns. Farmers have many options for choosing equipment that is required to grow and harvest a crop. Farmers may own their own equipment, lease it, or have the field operations completed using custom operators. Considering the above facts and importance of paddy, in-order to reduce cost of cultivation a multi crop roto drill cum herbicide applicator was developed by combining three varied machines such as rotovator, seed drill and herbicide applicant or equipment at College of Agricultural Engineering, Bapatla. A tractor drawn roto drill cum herbicide sprayer was developed, evaluated and compared its cost economics with individual operations. Roto drill is the combination of rotavator, seed hopper and rocker sprayer pump. It pulverizes the soil, drills the seed and applies herbicide in single pass of tractor. The cost activity of multi crop roto drill cum herbicide applicator for performing three tasks was estimated as Rs/h. 641.00. While the individual costs of operation for tillage, sowing and herbicide application were computed as Rs/h. 571.00, 540.00 and 95.00 respectively. The cost of operation per one hour for developed multi crop roto drill cum herbicide applicator was 46.72% less when compared with costs of individual tasks.