USE OF PAN EVAPORATION FOR ESTIMATING THE TOTAL DOSE AND PROGRAMMING THE IRRIGATION OF SUGARCANE

Sugarcane is scheduled to be cultivated over an area of 100 000 ha in the Gharb region of Morocco. Irrigation is necessary for growing cane in this region as the total annual precipitation does not exceed 500 mm with most of this rainfall occurring when the crop water demand is low. According to preliminary studies the total annual cane irrigation requirement in this area is about 1000 mm. Considering the high cost of energy, the irrigation of sugarcane may not be economic unless significant savings are made by reducing the amount of water applied annually. The objective of the study reported here was to quantify the effect of reduced irrigation regime on sugar yield. Six treatments were set up. Each treatment was a combination of irrigation regime and interval. The irrigation regimes were based on pan evaporation and crop factors that varied with stage of growth. The first year of the experiment was harvested in April 1986 and the results appear promising in terms of saving water. © 1990.