responses of various common bean (phaseolus vulgaris l.) genotypes to zinc deficiency

zink deficiency in calcareous soils of arid and semi-arid regions is a limiting factor for crop yield. bean is considered as one of sensitive plants to zinc (zn) deficiency. to study the responses of various bean genotypes to soil zinc deficiency, a greenhouse experiment was carried out. a factorial completely randomized design with three replications was conducted. the first factor was two levels of zn (0 and 10 mg zn kg-1 soil) and the second factor was 12 genotypes of beans. zn uptake was found to be significantly correlated with zn level, however, zinc concentrations of both old and young plant portions had lower correlation. therefore, zinc uptake is a suitable characteristic to identify zinc efficient genotypes compared to zn concentration. adequate zn supply in studied genotypes enhanced shoot dry matter production of bean genotypes compared to plants cultivated under low zn condition. under low zn condition, dry matter production of young part of shoot was lower in the zn inefficient genotypes, but in the old portion of the shoot exhibited higher dry matter. in addition, compared to efficient genotypes, responses of inefficient bean genotypes were higher to zinc application.