The effectiveness of seed priming and foliar application of zinc- amino acid chelates in comparison with zinc sulfate on yield and grain nutritional quality of common bean

Abstract

The efficacy of seed priming and foliar application of zinc-amino acid chelates including zinc-histidine [Zn(His)2] and zinc-methionine [Zn(Met)2] in comparison with zinc sulfate (ZnSO4) on yield and grain nutritional quality of two common bean cultivars (Phaseolus vulgaris L., cvs Talash and Sadri) was investigated in a severely Zn-deficient calcareous soil (DTPA-Zn: 0.38 mg kg−1 soil) in a pot experiment. Bean response to Zn application varied depending on the Zn fertilizer, application method and cultivar. In ‘Talash’, seed priming with [Zn(His)2] and [Zn(Met)2] led to 24.1 and 11.6% increase in the grain yield of bean in comparison with ZnSO4 treatment, respectively. In both cultivars, foliar application of [Zn(His)2] led to significant increase in the grain yield in comparison with ZnSO4. The highest grain Zn concentration was obtained by seed priming with [Zn(Met)2] in ‘Sadri’ and [Zn(His)2] in ‘Talash’, respectively. For Zn-amino acid chelates, seed priming was more effective than foliar application in increasing grain yield and Zn concentration. Foliar application of [Zn(His)2] and [Zn(Met)2] in ‘Sadri’ and [Zn(Met)2] in ‘Talash’ resulted in higher protein content in bean grain as compared with ZnSO4. In both cultivars, foliar application of [Zn(Met)2] was the more effective than seed priming to increase grain protein content. The highest water-soluble carbohydrates concentration of grain was obtained by seed priming with [Zn(Met)2] and [Zn(His)2] in ‘Sadri’ and ‘Talash’ cultivars, respectively. Therefore, seed priming with [Zn(His)2] and ZnSO4 in ‘Sadri’ and [Zn(Met)2] in ‘Talash’ can effectively be used for improving yield of common bean in Zn-deficient calcareous soils.