Field experiment was conducted to study the response of tomato to variable irrigation and lateral spacing at the irrigation research farm of SHAITS (formerly Allahabad Agricultural Institute) - Deemed University, Allahabad, (U.P), India, during the winter crop growing season of November to April on clay loam soil in order to evaluate the effect of irrigation levels (25%, 75%, 125%, 175% and 225%) and lateral spacing (0.5 m and 1.0 m) on marketable fruit yield, irrigation production efficiency, total cost of production, gross return, net return and benefit-cost-ratio of tomato under semi-arid climate of Allahabad region. The irrigation during the crop growing season was applied when sum of last five years of daily pan evaporation from USWB class A pan reaches approximately to predetermined value of 16.3 mm, after accounting the rainfall. Irrigation at 175% of pan evaporation replenishment resulted in significantly higher marketable fruit yield, gross return, net return, and benefit cost ratio, further increase in irrigation level reduced the marketable fruit yield, gross return, net return and benefit cost ratio for both 0.5 m and 1.0 m lateral spacing. The higher irrigation production efficiency was observed at 25% of pan evaporation replenishment, when laterals were placed at 0.5 m spacing. The higher mean marketable fruit yield was observed at 175% of pan evaporation replenishment and higher mean irrigation production efficiency was observed at 25% of pan evaporation replenishment. The lateral spacing 0.5 m gave higher mean marketable fruit yield and higher mean irrigation production efficiency as compared to 1.0 m lateral spacing. The relationship between seasonal water applied and marketable fruit yield, gross return, net return and benefit cost ratio exhibit a strong quadratic relationship for both 0.5 m and 1.0 m lateral spacing. The overall results reveal that the drip irrigation for tomato crop is economically profitable in Allahabad region.
