Abstract: The present study was carried out with different levels of irrigation, fertilizer and mulch to assess the growth habit, physiology aspect of plant and response to fertigation on fruit yield of pointed grourd in a sub-tropical climate. In drip irrigation method, irrigation and fertilizer are applied through drip simultaneously are placed near the active crop root zone unlike furrow irrigation method. With the results, effectiveness of the applied fertilizer and irrigation increases. If mulch is placed at the top of soil, the upward movement of water through capillary is reduced substantially and adequate soil moisture is maintained in root zone. To evaluate the response of these inputs through drip system, the drip irrigation system was selected and different treatments was tested. In pointed gourd irrigations applied at the rate of 100% of Pan Evaporation (PE) at two days interval produced statistically at par fruit yield in comparison to 80% PE. Hence irrigation at 80% PE may be followed as saving of irrigation water and irrigation water use efficiency in this treatment was higher. With regard to combination of irrigation and fertilizer level, fertigation with 75% of recommended dose with 80% PE irrigation schedule produced maximum fruit yield of 5.46 t ha-1 and was comparable with fruit yield of 100% of the recommended dose of fertilizer. Thus application of fertilizer through drip in eight equal splits at monthly interval saved 25% fertilizer without any adverse effect on fruit yield. Under lowest level of fertilizer, FUE, NUE and phosphorus/potassium was maximum. However under the highest level of fertilizer, these efficiencies were low. Variation in carbon dioxide exchange rates due to leaf position, photosynthesis, stomata conductance and diurnal changes in male and female plants of pointed gourd (Trichosanthes dioica Roxb.) had significant changes. From the present study, it is inferred that fertigation increases fertilizer use efficiency as well as save good amount of irrigation water.