Internal and External Phosphorus Requirements for Optimum Grain Yield are Associated with P-utilization Efficiency of Wheat Cultivars

ABSTRACT

Considerable variation exists among wheat cultivars for phosphorus (P) acquisition and utilization to produce higher yields. We investigated critical P requirements for optimum grain yield of two wheat cultivars contrasting in P-use efficiency, i.e., NIA-Sunder (P-efficient) and NIA-Saarang (P-inefficient). Grain yield, P accumulation, and other P-efficiency relations of both cultivars increased with progressive addition of P, but at variable rates. NIA-Sunder exhibited higher grain yield, grain P concentration, harvest index, and P-use efficiency at all P levels as compared to NIA-Saarang. Internal P requirement for achieving 95% relative grain yield in NIA-Sunder and NIA-Saarang was obtained when P concentration in their grains was 4.07 and 3.48 mg g⁻¹ recorded at external P levels of 57.2 and 78.1 mg kg⁻¹ soil, respectively. Overall, NIA-Sunder accumulated 15% more grain P and required 27% less external P for attaining 95% relative yield than P-inefficient cultivar. Results suggested that internal and external P requirements aiming at optimum grain yield are associated with genotypic variations in wheat cultivars for P-utilization efficiency.

KEYWORDS:

• Critical P concentration
• harvest index
• P-use efficiency
• recovery efficiency
• wheat

Acknowledgments

The authors greatly acknowledge the cooperation of Dr Mehboob Ali Sial (Deputy Chief Scientist/Wheat Breeder), Plant Breeding and Genetics Division, Nuclear Institute of Agriculture, Tandojam for providing the seed of wheat cultivars for conducting the study.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.