Abstract

M. Dhital, S.M. Shakya, M.D. Sharma and J.P. Dutta

An experiment was carried out to evaluate the effect of nitrogen on commercial onion varieties for off season green production in sandy loam soils at Shukranagar Village Development Committee (V.D.C), Chitwan, Nepal, from July to November 2008. The field experiment was laid out in two factors factorial randomized complete block design (RCBD) with five levels of nitrogen (0, 40, 80, 120 and 160 kg ha-1 ) and two varieties (Agrifound Dark Red and Nasik-53) with four replications. Green onion yield was the highest (42.38 t ha-1 ) at 120 kg N ha-1 where as it was reduced to 40 t ha-1 at 160 kg N ha-1 . The combination of 120 kg N ha-1 and Agrifound Dark Red (AFDR) produced the highest green yield (43.8 t ha-1 ). The plant height (59.81cm) and numbers of leaves (9.47) per plant measured at 60 days after seedling transplanting (DAT) were the highest at 120 kg N ha-1 which was significantly higher than the control 48.58 days and 7.287 leaves per plant respectively). Number of leaves plant per plant, plant height, percentage doubled plants and immature bulb diameter showed positive correlation with green yield. The earliest maturity (51.88 days) of the crop was at 120 kg N ha-1 while the most delayed was in the control (58.75 days). AFDR matured earlier (52.25 days) than N-53 (56.5 days). The highest post harvest loss (29.13 %) was in the treatment of 160 kg N ha-1 after 6 days of harvest. Benefit cost ratio of AFDR at 120 kg N ha-1 (5.14) was the highest as compared to N-53 (4.46) at same level of N.