GROWTH AND YIELD RESPONSE OF OKRA (Abelmoschus esculentus L.) AS AFFCETED BY VARYING RATES OF NPK FERTILIZER AND COWDUNG MANURE IN A SEMI ARID ECOLOGY

Abstract

A two-year field study (2019–2020) at Bayero University Kano, Nigeria, assessed integrated nutrient management (INM) effects on okra growth and yield using a 4 × 4 factorial randomized complete block design. Treatments included NPK fertilizer (0, 100, 200, 300 kg ha⁻¹) and cow dung manure (CDM) (0, 2.5, 5.0, 7.5 t ha⁻¹). NPK, CDM, and their interaction significantly (P < 0.05) influenced growth and yield. In 2019, 300 kg ha⁻¹ NPK produced taller plants at 4 weeks after sowing (WAS), while 100–300 kg ha⁻¹ NPK enhanced height at 8 WAS. CDM (7.5 t ha⁻¹) consistently increased plant height in both years, with the tallest plants at 4 WAS in 2019 under 300 kg ha⁻¹ NPK + 2.5 t ha⁻¹ CDM. Similar trends were observed for leaf number and area. CDM (7.5 t ha⁻¹) significantly increased branches at 8 and 12 WAS in 2019 and 8 WAS in 2020. Stem girth was highest at 12 WAS in 2019, with 200 kg ha⁻¹ NPK + 7.5 t ha⁻¹ CDM. NPK delayed 50% flowering in 2019. The highest pod yield obtained with 200 kg ha⁻¹ NPK across both seasons, peaking when combined with 7.5 t ha⁻¹ CDM, confirming INM’s potential for sustainable okra production in semi-arid regions.