effect of deficit irrigation management for basin and drip tape irrigation on water use efficiency, yield and morphological characteristics of onions

this study evaluates the effect of irrigation method on the water use efficiency and yield of onions at the zahak agricultural research station in sistan province. the testing was conducted using a split plot arrangement and a randomized complete block design with three replications during the 2005-2006 crop seasons. irrigation methods were basin and drip tape irrigation and the irrigation levels tested were 100% (t1), 75% (t2) and 50% (t3) of the water requirement of the plants. analysis of data from two years of study showed that a change of basin irrigation to drip tape significantly increased the performance of the bulb. the maximum bulb weight and height of the plant was significantly influenced by irrigation type and amount on all levels. a comparison of the mean performance showed that full irrigation produced the greatest amount of bulbs (24.75 tonha). it also showed that the amount of water used for the drip tape treatment 3.86 kg/m3 was significantly greater than for the basin irrigation method (2.80 kg/m3). there was a small significant difference between irrigation treatments with the highest value for both treatments shown for t2.