4. Conclusions
Irrigation scheduling based on IW/CPE approach appreciably
reduced the irrigation requirement without any unfavourable
effects on sugarcane yield. Where a fixed depth of water is
applied for irrigation at an optimum level of IW/CPE ratio, the
farmer need not change the amount of water from one
irrigation to another. This approach also permits development
of an irrigation calendar for sugarcane planted on different
dates, provided the pattern of pan evaporation does not show
much yearly variation during the growing season. In the event
of rain, the interval between two irrigations would increase.
Based on the results of this experiment in subtropical India,
irrigation should be applied at IW/CPE ratio of 0.75 for a silty clay loam soil and 1.00 for a sandy loam soil during the tillering
period in sugarcane plant and ratoon crops.