Effect of Inter-row and Intra-row Spacing on Phenological Characters of Cowpea (Vigna unguiculata L. Walp) Varieties in Semi-arid Region of North-Western Nigeria

Abstract

Aims: Field trials were conducted at the research farm of the Institute for Agricultural Research, Ahmadu Bello University, Samaru, Zaria, Nigeria during the wet seasons of 2006 and 2007 to investigate the effect of inter-row and intra-row spacing on the growth and phenological characters of cowpea varieties in semi-arid region of north-western Nigeria. Study Design: Randomised Complete Block Design was used with three replications. Place and Duration of Study: Field experiments were carried out during the 2006 and 2007 rainy seasons at Institute for Agricultural Research farm Samaru in Ahmadu Bello University, Zaria, Nigeria (Lat. 07°38°E, long. 11°11°N and altitude 686 m). Methodology: The study was conducted to investigate the effect of three inter-rows spacing (60, 75 and 90 cm) and three intra-row spacing (20, 25 and 30 cm) on the performance of two cowpea varieties (SAMPEA 6 and SAMPEA 8). Experimental field was subjected to standard agronomic practices and factorial treatments where tested on growth and phenological characters (stand establishment count, plant height, canopy spread, number of branches, 50% flowering, 50% physiological maturity and yield). Results: The results showed that inter-row spacing and intra-row spacing had no significant effect (P>0.05) on most of the vegetative growth attributes and phenological characters assessed. However, inter-row spacing and intra-row spacing had significant effect (P<0.05) on stand establishment count. Every increase in inter-row spacing (60 cm to 90 cm) and intra-row spacing (20 cm to 30 cm) was accompanied with a corresponding decrease in stand establishment count in all the years and the mean. SAMPEA 6 performed better than SAMPEA 8 in all the characters measured which could be attributed to the genotype of the varieties used. Conclusion: Inter-row spacing of 60 cm and intra-row spacing of 20 cm and SAMPEA 6 is recommended for cultivation in semi-arid region of north-western Nigeria.