Predicting the Effect of Water and Salinity Stresses on Yield and Water consumption of Wheat

Abstract

A computer model was developed to predict wheat yield and its water consumptive use. The developed model called
"Wheat-Stress". The model calculates water depletion from root zone using equations described at FAO publication No
56.The model was validated using two-year experimental data for wheat planted during growing seasons of 2003/04 and
2004/05 to study the impact of skipping the 5th or the 6th irrigation on the yield of two wheat cultivars i.e. Sakha 93 and Giza
168. "Wheat-Stress" model was also used to predict wheat yields under the following hypothetical situations: (1) Reducing
the amount of irrigation water by 20 %. (2) Using saline water for irrigation. Results showed that the model prediction gave
good agreement with actual yield, for both varieties over the two growing seasons. Results also indicated that the yield of
both varieties was reduced under deducting 20 % of irrigation water by 8.62 and 8.76 % for Sakha 93 and Giza 168,
respectively. Furthermore, using saline water for irrigation reduced wheat yield by 4.14 and 4.38 % for Sakha 93 and Giza
168, respectively. Water consumptive use under total irrigation was reduced by 18.54 and 11.64% for both growing seasons,
respectively, under saving 20 % of total water irrigation. Whereas, under saline water irrigation, water consumptive use was
reduced by 15.02 and 11.93 % for both growing seasons, respectively. The developed model could be modified to predict the
yield of other crops using specific crop parameters presented at FAO publication No 56.