Influence of Phosphorus and Zinc Application on Leaf Area Ratio (LAR) of Cowpea (Vigna unguiculata (L.) Walp) Varieties in the Scrub Savanna of Nigeria

Currently there is increasing attention to evaluate the possible Relative Growth Rate (RGR) of plant species, and whether disparities are principally caused by structural or physiological characters. Leaf area ratio (LAR) defined as leaf per unit total biomass net assimilation rate. Phosphorus (P) Zinc (Zn) most important factors affecting LAR cowpea (Vigna unguiculata L. Walp). Two field trials were conducted at Faculty Agriculture Agricultural Engineering Research Farm Abubakar Tafawa Balewa University, Bauchi, North Eastern, Nigeria, between 2006 2007. The experiments consisted fifty-four (54) treatments consisting six varieties three SSP levels levels. objective this study was examine in different P Zn none? Bauchi located 100 22’, N latitude 900 47’ E longitude about 109.45m above sea level. Results indicated that year, varieties, found have significant (P<0.05) effect on LAR. Kanannado recorded highest than other five varieties. differences observed may be attributed phenotypes climatic such rainfall, sunshine availability nutrients. increase an encouraging influence crop growth rate, dry matter yield. Application 50kgha-1 IT89KD-288 more valuable for enhancement hence recommended growers area.