Water Requirements of Some Crops in North Sinai Governorate: 1- Effect of Irrigation Intervals and Plant Density on Actual Evapotranspiration , Water Use Efficiency and Yield of Sugar Beet Plants.

Abstract

This study was carried out at the Experimental Farm of the Faculty of Environmental Agricultural Sciences, Suez Canal University in El-Arish, during two successive seasons, 2004/2005 and 2005/2006. The experiment aimed to study the effect of irrigation intervals and distances between drip irrigation laterals on sugar beet (Beta vulgaris L. cv. PL12). The experiment was assigned for cultivating sugar beet plants. The experiment included 9 treatments for the interaction between 3, 5 and 7 days irrigation intervals and 40, 50 and 60 cm distances between drip lateral lines. Each treatment plot consisted of 3 lateral lines, each was 10 m long. The treatments plot area was either 12, 15 or 18 m 2 . Seeds of sugar beet plants were sown on the 1 st of October in 2 successive seasons, 2004/2005 and 2005/2006, at the rate of 3 kg.fed -1 . Actual evapotranspiration and fresh and dry yield of roots and top weights increased with decreasing irrigation intervals. However, they were increased with increasing the distance between irrigation lines in both seasons. The water use efficiency increased with increasing irrigation intervals, while it was decreased with increasing the distance between irrigation lines. The highest sugar yield was obtained when sugar beet was irrigated every 5 days, while the highest sugar beet was obtained for 60 cm distance between irrigation lines in both seasons. The highest value of actual evapotranspiration was obtained at 3 days irrigation intervals with 60 cm distance between irrigation lines. The irrigation every 3 days with 60 cm distance between irrigation lines gave the highest yield, while the irrigation every 7 days with 40 cm distance between irrigation lines gave the highest water use efficiency.