ECONOMIC ANALYSIS OF RATES OF FERTILIZER APPLICATION AND WEED CONTROL METHODS IN SWEET POTATO (Ipomoea Batatas L.) PRODUCTION IN LAFIA, NASARAWA STATE.

The study was carried out to investigate the profitability of sweet potato production in Lafia under different fertilizer rates application and weed control methods. The research was carried out at Lafia and Agyragu Koro of Nasarawa State. The factors comprised of fertilizer application of two NPK 30 and 60kgha-¹ and 0kgha-¹ of untreated control. The weed control methods comprised of herbicides application of PRE S-metalochlor followed by hoe weeding at 6 WAP, Post emergence application of fluazifop-P-butyl followed by hoe weeding at 6 WAP, hoe weeding at 3 and 6 weeks after planting (WAP) and a weedy check (control), and two plant spacing of 35x75cm row in spacing and 45x75cm row in spacing. Data on tuber yield ha-¹, and cost of inputswere recorded throughout the period of observation at both locations. Higher tuber weight, numbers of leaves and yield was recorded at both locations with the treatment application of 60kgha-¹. The higher yield was recorded with plots treated with Pre emergence application of Smetolachlor followed by hoe weeding at 6 WAP while minimum yield was recorded in the control plots (weedy check). In both locations, the gross margin of the sweet potato increased with the application of fertilizer at the rate of 60 kg ha-1, pre-emergence application of Smetolachlor and planting density of 40 cm intra row spacing.