| The response
of onion (Allium cepa ) to different irrigation schedules was studied in
Trakya, Turkey, during 1997 and 1998. Onion crop was subjected to four
irrigation treatments according to available soil water depletion
fractions (0.30, 0.50, 0.70, and no irrigation). Irrigation thresholds
(amount of soil water at 0.40 m depth) were used as criteria to initiate
drip irrigations. For each differential water treatment, the parameters
of bulb morphology (diameter and height), solids soluble in bulbs, bulb
weight, and total yield were analysed. Yield and yield components
except solids soluble in bulbs were affected by irrigation and soil
water depletion fractions. The highest yield was obtained from the
plots to which irrigation water was applied at a soil water fraction
level of 0.30. The maintenance of soil moisture depletion level at 0.30
required 339.4 mm (in 14 applications) and 227.2 mm (in 13
applications) of irrigation water in 1997 and 1998, respectively. The
seasonal evapotranspiration of onion was 420.0 mm in 1997 and 351.2 mm
in 1998. |
