This study is primarily related to growth regulators focusing on a major group ethylene produced from a solid i.e. calcium carbide (C2H4). A experiment was conducted at Experimental Area, Institute of Horticultural Sciences, University of Agriculture, Faisalabad to evaluate the effectiveness of slowly periodically released ethylene (C2H4) from coated and encapsulated calcium carbide (CaC2) growth and yield of tomato cv ?Sahal? under tunnel structure. Calcium carbide @ 100, 200 and 300 mg plant-1 along with recommended doses of NPK was placed 10 cm deep at two weeks after transplanting seedlings. Required weight of CaC2 granules was either filled into the gelatin capsules or coated with coating materials i.e. wax, paraffin, liquid polyethylene solution or emulsion paint. Recommended levels of NPK alone were also included for comparison. Each treatment was replicated four times in Randomized Complete Block Design. Overall, 200 mg polyethylene, and paint coated, and 200 mg encapsulated CaC2 were most prominent among all treatment. The study indicated that application of coated calcium carbide act as plant growth regulator and nitrification and denitrification inhibitor.