Crop demand of manganese

摘要

The objectives of this study were to evaluate some of the popular rotation crops grown in Hungary for tolerance to low external Mn~(2+) levels and to determine the critical tissue concentration of Mn~(2+) deficiency during early stages of growth. The minimum Mn~(2+) concentration required in soil nutrient contents was 42.5 mg kg~(-1) for sunflower, 24.3 mg kg~(-1) for tobacco and 10.2 mg kg~(-1) for triticale. Sunflower, tobacco and triticale achieved optimum growth at 48.0-65.0 mg Mn~(2+) kg~(-1), 24.9-32.1 mg Mn~(n+) kg~(-1) and 28.7 to 29.6 mg Mn~(2+) kg~(-1), respectively. Critical shoot Mn~(2+) concentration at early stages of growth was 53.6 mg kg~(-1) in sunflower, 458.0 mg kg~(-1) in tobacco and 193.8 mg kg~(-1) in triticale. Our results demonstrate that the tolerance to low external Mn~(2+) (triticale: <30.2 mg kg~(-1); sunflower: <56.2 mg kg~(-1); tobacco: <69.3 mg kg~(-1)) and the critical tissue Mn~(2+) levels for deficiency varied significantly between crop species tested.