EFFECT OF IRRIGATION REGIMES ON POTATO PRODUCTIVITY IN SANDY SOILS UNDER SPRINKLER AND DRIP IRRIGATION SYSTEMS

Abstract

A field experiment was conducted at Ali Mubarak agricultural research station (30o 35´ N, 30° 15´ E, and 32 m above sea level), El-Bustan area, El-Behiera Governorate, Egypt in winter seasons of 2008-2009 and 2009-2010. The aim was to study the effect of four irrigation regime s (I1 = irrigation with amount of water equals 125% of potential evapotranspiration (ETp) determined by class A pan, 100% ETp, 75% ETp, and 50% ETp), and two irrigation systems (sprinkler and drip) on potato fresh yield, potato dry matter, starch percentage, water requirements, water consumption, and water utilization efficiency (WUtE), as well as developing local potato crop coefficient (Kc). A split plot experimental design with four replicates was used. The main plots were assigned to the irrigation systems (drip and sprinkler), and the sub-plots were assigned to the irrigation treatments. Potato (Spunta variety) was used in the present experiment. Results revealed that drip irrigation recorded significant increase in fresh potato yield by 23.0 and 7.0% in the 1st and 2nd seasons, respectively as compared with sprinkler irrigation system. Under the experimental conditions, that potato fresh yield increases by increasing amount of irrigation water up to ETp 125% in the two growing seasons. The highest yields of potato were 14.325 and 17.902 tonfed-1 in the 1st and 2nd seasons, respectively, were obtained from ETp 125% irrigation regime with drip irrigation system. The ETp 125% irrigation regime produced the highest values of potato dry mater and starch% reached (2.358 and 2.975 tonfed-1) and (18.8 and18.5%), respectively, in the 1st and 2nd seasons. The highest fresh potato yields e.g. 14.325 and 17.902 tonfed-1 were obtained with ETp 125% irrigation regimeunder drip system, in the 1st and 2nd growing seasons, respectively. Seasonal water requirements for potato crop under drip irrigation system were 35.0 and 38.6 cm in the 1st and 2nd seasons, respectively. Seasonal water consumptive use values for potato crop under drip irrigation system were 27.8 and 32.0 cm in the in the 1st and 2nd seasons, respectively. The highest WUtE average value of 11.37 kg potato yield/m3 applied water resulted from the interaction between ETp 100% irrigation regime and the drip irrigation system. The 2-year average value of local potato crop coefficient (Kc) was 0.81 under drip irrigation.