Boron toxicity alleviation by zinc application in two barley cultivars differing in tolerance to boron toxicity

Zinc (zn) deficiency and boron (b) toxicity are often encountered simultaneously in soils of semi-arid and arid regions. a sand culture experiment was conducted to evaluate the alleviation of b toxicity by application of zn to barley genotypes. two barley cultivars [clipper (b toxicity sensitive/zn-inefficient) and sahara (b toxicity tolerant/zn-efficient)] were grown with four b (0.1,0.5,1.5 or 3 mg kg -1) and two zn (0.1 or 1.0 mg kg -1) levels,for 35 days. high rates of b significantly reduced plant dry matter,more prominently in clipper. application of zn significantly improved shoot and root dry matter in clipper in all b treatments. boron application significantly increased b in shoots and roots of both genotypes,but the increase was more prominent in clipper than sahara. boron concentration in roots of clipper was almost double that in sahara irrespective of zn and b treatments. application of zn at 3.0 mg zn kg -1 decreased b concentration in both cultivars. higher zn concentration in sahara resulted in lower b:zn concentration ratio than clipper. the interactive effects of b and cultivars suggested the possible use of genetic variations for ameliorating b toxicity and zn deficiency. © 2015,university of agriculture. all right reserved.