RESPONSE OF SQUASH TO DEFICIT IRRIGATION AND POTASSIUM FERTILIZATION UNDER SOLAR – POWERED DRIP IRRIGATION

The availability of fresh water and energy resources in remote locationsis a major challenge for agricultural crop production in many countriesin the Middle East region. Using limited water resources efficiently iscrucial to sustain rapidly population growth. This research aimed toinvestigate the possibility of enhancing productivity and waterproductivity of squash crop through deficit irrigation technique. Two fieldstudies were carried out to investigate the response of squash crop todeficit irrigation (DI) technique and potassium fertilization (K) over thespring and fall seasons of 2018. The irrigation treatments were based onthe reference evapotranspiration (ETo). The results showed that theoptimum squash seed yield could be obtained with K fertilizer level of 250kg K_2O ha^-1 and irrigation with amount of water equals 75% of ETo usingDI with laterals placed at 0.15m from crop row or 50% of ETo in the laststage using RDI techniques. Fully irrigated (1.0 ETo) treatments had thehighest values of yield and yield components of squash and there were nosignificant differences with RDI and DI with 0.75 ETo. The application ofRDI can save more than 20% of applied water with no significantreductions in squash yield. Potassium rates enhanced squash yield andwater productivity with the greatest value at 250 kg K_2O_5 ha^-1.