INFLUENCE OF DIFFERENT RATES OF PHOSPHORUS AND POTASSIUM FERTILIZER APPLICATION ON GROWTH AND YIELD OF COWPEA (Vigna unguiculata L. Walp) VARIETIES

Author(s): Ndagana M. K., Aliyu, J.A., Adamu S.
Volume/Issue: Volume 3 , Issue 2 (2023)

ABSTRACT:

The study evaluated the influence of rates of phosphorus (p) and potassium (K) fertilizers on the growth and yield of two cowpea verities (IT10k-863-11) and IT81D-1228-14)for two consecutive cropping seasons (2020 and 2021). Three/rates of p(0, 20, 30kg/ha PO) and four 2 5 rates of K (0, 20, 30, 40kg/ha KO) were utilized. The experimental design was a 2 x 3 x 4 factorial 2 arrangement in randomized complete block replicated three times. Result indicated that leaf area index (LAI) at four weeks after sowing (LAI) at four weeks after sowing (4 WAS) in 2020, significantly (p<0.05) increased as p rates increased. However, at 10 and 12 WAS in 2020 and 2021 leaf area index (LAI) significantly (p<0.05) incased with 20kg/ha pO but reduced at 5 5 30kg/ha PO application. In both cropping season, 30 and 40kg/ha produced similar but highest 2 5 LAI at 4, 8 and 10 WAS. Interaction of P and K atmostrated that at 4 WAS application of only 30kg/ha KO without P gave highest LAI (0.09 and 0.09) in both cropping seasons. All the yield 2 parameters progressively increased as rates of K increased Highest number of fresh pods/plant and seeds/pod, heaviest fresh pods per plant and as well as seed yield were associated with 40kg/ha KO application in both cropping seasons. The application of 40kg/ha KO with no 2 2 application of P also produced better yield and yield attributes of the cowpea, hence 40kg/ha KO 2 application without P was recommended for sustainable cowpea production in the Northern Guinea agro-ecological zone of Nigeria, especially when the soil has high available p (above the critical p level of 7mg/kg recommended for cowpea production).

KEYWORDS:

Cowpea, Fertilizer rates, Phosphorus, Potassium, Growth and Yield