RESPONSE OF COWPEA (Vigna unguiculata L.Walp) VARIETIES TO PHOSPHORUS LEVELS IN SUDAN SAVANNA OF NIGERIA

Abstract

Field trials were conducted during the 2015 rainy season at the Bayero University Kano Teaching and Research Farm (11⁰ 58’N, 8⁰25’E and 475m above sea level) and National Institute of Horticulture (NIHORT) Bagauda (lat. 12⁰ 08'N, long. 8⁰ 32'E, 500m above sea level). The study was conducted to determine the response of cowpea varieties to phosphorus levels in the Sudan savannah of Nigeria. The treatments consisted of four cowpea varieties (UAM-09-1051-1, IT99K-573-2-1, IT99K-573-1-1, and TVX 3236) and phosphorus fertilizer (SSP) (0, 20, and 40kg/ha) which were laid out in a Randomized Complete Block Design (RCBD). The result revealed that application of 40 kg/ha P₂O₅ statistically recorded the highest grain yield/ha at BUK. No significant phosphorus effect was recorded on grain yield/ha at Bagauda. The findings of the study also revealed that there was significant varietal effect on cowpea growth and yield at both study locations. Higher grain yield was recorded from variety IT99k-573-2-1 (1193.400 kg/ha), followed by variety TVX 3236 (950.900 kg/ha) and IT99k-573-1-1 (776.500 kg/ha) at BUK while no significant effect of variety was recorded at Bagauda. The result of the simple correlation analysis revealed significant negative and positive association between growth and yield parameters. Thus based on this findings, application of 40 kg/ha P₂O₅ can be recommended for better cowpea growth and yield. Similarly, variety IT99k-573-2-1 can be recommended for both locations.