Effect of variable water application rates on yield of flax and irrigation water use efficiency

The obtained results could be summarized as follows: Seed yield and other plant parameters such as plant height, capsules number per plant and protein content had significantly affected with various irrigation treatments. Irrigation at 100%, 80% from cumulative pan evaporation and 50% depletion of available soil moisture were superior to traditional treatment, respectively. Irrigation at 100 % pan evaporation recorded the highest values of flax seed yield (540.8 and 539.4 kg/fed.), straw yield (3.545and3.767ton/fed.),plant height(114.9 and 116.2cm), technical length (101.8 and 100.5cm)and capsules number per plant(13.93and14.89)in the first and second seasons, respectively Irrigation of flax plants at 60 % depletion of available soil moisture resulted in the highest oil content (41.98 and 40.4 %) in the first and second seasons, respectively. Irrigation at high flow rate( 60 L/sec) increased values of plant height, technical length, number of capsules per plant, seed yield, straw yield, oil and protein contents compared to low flow rate (30L/ Sec.)in the two growing seasons. • The interaction between irrigation intervals and flow rate (I x F) had significant effects on the technical length in the 1st season, while in the 2nd season, the interaction had a significant effect on all parameters except seeds yield and protein content. The lowest values of water applied (1914.83 and 1967.6m. /fed.) were found under irrigation at 100 % pan evaporation , while the highest values of water applied (2463.5and 2530.5 m. /fed.) were recorded with traditional irrigation in the 1st and 2nd seasons, respectively. The amount of water applied (2266.23 and 2334.2m. /fed.) with flow rate of 30 L/sec was higher than that 2087.9 and 2140.1m. /fed. with flow rate of 60 L/sec in the 1st, and 2nd , seasons, respectively. -Water consumptive use (m. /fed) generally behaved the same trend of water applied for all treatments.