EFFECT OF IRRIGATiON AND NITROGEN ON THE GROWTH AND YIELD AND NUTRIENT CONTENT OF ONION

Abstract

A field experiment was conducted at the Sher-c-Bangla Agricultural University Farm. Dhaka-1207 during the Robi season of 2007-2008 to evaluate the effect of irrigation and nitrogen on the growth and yield of onion. l'he research was carried out with four levels of nitrogen viz; 0. 50, 100 and 150 kg ha" and four levels of irrigation viz . I () : no irrigation, 12: two times irrigation. J.. : four times irrigation. I S : eight times irrigation in split plot design. Data were recorded on yield and yield components. The experiment was laid out in split plot design with three replications. Single application of N had significant influence on leaf length, vertical length of bulb, dry weight of leaf and dry weight of bulb and yield of bulb. The dose of nitrogen N,(l00 kg ha") gave the highest plant height, leaf number, leaf length, vertical length of bulb, horizontal length of bulb, thy weight of leaf, dry weight of bulb. The maximum plant height, leaf number, leaf length, vertical length of bulb, horizontal length of bulb, dry weight of leaf, dry weight of bulb were produced by 4 (four times of irrigation) treatment. The significant combined effect between different number of irrigation and levels of nitrogen in respect Plant height, leaf number, leaf length, vertical length of bulb, horizontal length of bulb, dry weight of leaf, and dry weight of bulb were observed. The highest Plant height, leaf number, leaf length. vertical length of bulb, horizontal length of bulb, dry weight of leaf, and dry weight of bulb were recorded from the treatment combination of I4N1 . The total yield of bulb was significantly varied due to different levels nitrogen doses applied in onion. The highest yield of onion (5.44 kg/plot and 17.94 i/ha) was recorded from N1 (100 kg N'ha) treatment. The total yield of bulb was significantly varied due to irrigation in onion. The highest yield of onion (5.04 kg/plot and 17.94 tlha) was recorded from [4 four times of irrigation) treatment. The combined effect of irrigation and levels of nitrogen performed significant variation on yield per plot. The highest bulb yield per plot (3.53 kg/plot and 18.6 t/ha) was recorded from the treatment combination of 1.1N1® , while the lowest yield of bulb (2.217 kg/plot and 15.03 i/ha) was observed from 10N0. On overall considerations. 100 kg N/ha and four times of irrigation were considered as optimum dose for the yield of onion under the experimental conditions.