Effect of Irrigation on Production of Onion Bulb

Abstract

An experiment was conducted to study the effect of soil moisture regime and irrigation frequency on onion bulb production during the year 1998-1999 at Rampur, Chitwan. Irrigation water was applied creating three soil moisture regimes, i.e. amount of water applied was equal to 100, 75, and 50 percent of water loss by Evaporation Pan during crop period. Four irrigation frequencies were maintained as the time lapse between two successive irrigations of 5, 10, 15 days interval and a zero irrigation. The experiment was laid-out in split-plot design applying soil moisture regimes in the main plots and irrigation frequencies in sub-plots, which was replicated four times. Fifty-three days old seedlings of onion cv 'Red Creole' were transplanted on 17 December 1998 and bulbs harvested on 29 April 1999 at 133 days after transplanting. Total amount of water applied was 309, 231.75 and 154.5 mm in 100, 75 and 50 percent soil moisture regimes, respectively, and number of irrigation given was 18, 9 and 6 at 5, 10 and 15 days interval, respectively, and 0 in no irrigation treatment. Observations were made on plant height, number of leaves per plant, plant stand, weight of bulb, bulb yield and biological yield. All these parameters were significantly affected by soil moisture regime and irrigation frequency. The highest bulb yield (17.19 t/ha) was obtained under 100 percent soil moisture regime and 10-days irrigation frequency followed by 5-days frequency in the same soil moisture regime (15.63 t/ha).

J. Inst. Agric. Anim. Sci. 23:35-40