Field experiments were conducted for 2 years in Peshawar, North West Frontier Province of Pakistan, to study the effect of three levels of boron (1, 2 and 3 kg/ha) on the amino acid composition of wheat protein. The soil was clay loam, alluvial in nature, with a pH value of 7·8, and hot-water-soluble boron content of 0·58 mg/kg.
Positive linear and negative quadratic effects of boron were observed on the protein and ash contents of wheat grain. Most of the essential amino acids were linearly increased with increasing supply of boron. There was a negative linear relationship of boron with all non-essential amino acids, except histidine and tyrosine.
Lysine was the most deficient amino acid in wheat protein. Chemical score based on this amino acid was positively affected by boron. There was also an improvement in the amino acid profile due to boron.