EFFECT OF NITROGEN AND WEED MANAGEMENT ON ONION (ALLIUM-CEPA)

A field investigation was carried out during the winter seasons of 1987-88 and 1989-89 to study the effect of 3 levels of nitrogen (50, 100 and 150 kg/ba) and 9 weed-control treatments. Weed biomass and the bulb yield of onion increasing with increasing levels of N. Pre-emergence application of oxadiazon (1.0 kg/ha) followed by manual weeding 45 days after transplanting showed the maximum weed-control efficiency of 77.0% compared with 60.5% with oxadiazon alone, and also increased the bulb yield by 81.4-254.9% over weedy check. Higher bulb yield was realized even at lower dose of 50 kg N/ha with weed-control treatments. However, weedy check gave the lowest bulb yield even with heavy fertilization (150 kg N/ha).