Effects of Phosphorus Fertilizer Source and Plant Density on Growth and Yield of Maize in Northwestern Pakistan

ABSTRACT

Phosphorus (P) fertilizer source and plant density are considered some of the most important factors affecting crop growth and yield. A field experiment was conducted to determine the impact of P source [zero-P control, DAP (diammonium phosphate), SSP (single super phosphate), and NP (nitrphos)] and plant density (D₁ = 40,000, D₂ = 60,000, D₃ = 80,000, and D₄ = 100,000 plants ha⁻¹) on growth and yield of maize (Zea mays L cv. Azam) on a P-deficient soil (6.6 mg P kg⁻¹) at New Developmental Agricultural Research Farm, North-West Frontier Province (NWFP) Agricultural University, Peshawar, Pakistan, during summer 2006 in wheat-maize cropping system. Physiological maturity was delayed, plant height was increased and leaf area was decreased significantly when maize was planted at highest (D₄) than at lowest plant density (D₁). Application of SSP resulted in earlier physiological maturity of maize than other P fertilizers. Grain and stover yield, harvest index, shelling percentage, thousand grain weight and grains ear⁻¹ were maximized at D₃ (80,000 plants ha⁻¹) and with application of P fertilizer. Highest benefit in growth and grain yield was obtained with application of DAP to maize planted at D₃. Application of DAP at D₃ gave 15, 29, and 19% higher grain yield than its application at D₁, D₂, and D₄, respectively. In conclusion, the findings suggest that growing maize at 80,000 plants ha⁻¹ applied with DAP can maximize productivity of maize in the wheat-maize cropping system on P-deficient soils.

Keywords:

• growth
• maize
• P source
• plant density
• yield
• Zea mays L

ACKNOWLEDGMENTS

Financial support from the Department of Agronomy, Faculty of Crop Production Sciences, NWFP Agricultural University, Peshawar, is greatly acknowledged. Assistance of Dr. Larry S. Murphy, president of FFF is also appreciated for sending a book, CDs and many other articles for the preparation of this manuscript.