Influence of Growth Regulators and Organic Inputs on Cowpea Productivity

Abstract

The relationship between leaf senescence in cowpea [Vigna unguiculata (L) Walp.] and yield was studied in pot 
grown population of a local variety, kanannado. Treatments comprising of farm yard manure (single and double 
application), 200 ppm benzyl amino purine (BAP), 15% coconut milk (CM) and a combination of both manure and 
the hormones were also applied to determine their effects on senescence and yield. The experiment was carried 
out at the International Institute of Tropical Agriculture (I.I.T.A), Kano station, Nigeria. Chlorophyll level was 
increased by all the treatments with greater increase in the 200ppm BAP and 15% CM treated plants. The level of 
chlorophyll also decreased with increase in age of the cowpea plants. Senescence commenced earlier and 
progressed faster in the manure treated plants while it was significantly delayed by 200ppm BAP and 15% CM. 
Fodder and grain yields were greater in all the treated cowpea plants compared with the control. Interactive 
effects were observed in the combined treatments (manure +15% coconut milk and manure +200 ppm BAP) as 
chlorophyll increased above that of manure and control plants. Also senescence process was delayed and yield 
was increased. The study suggests that leaf senescence in the photoperiod sensitive cowpea could be delayed 
by application of 200 ppm BAP, 15% CM and a combination of manure +15% CM and manure +200 ppm BAP and 
the delayed senescence resulted in increase in yield.