Genetic variation for Mg tissue concentration in pearl millet lines grown under Mg stress conditions

Efficient nutrient utilization by plants is extremely important in developing countries and is becoming more important in the developed countries as the costs of fertilizers are increasing. Pearl millet is a world food and forage crop usually grown on droughty soils low in nutrients. Eighty‐five genetically diverse pearl millet, Pennisetum glaucum (L.) R. Br. lines were grown in low Mg and K sand for three weeks to screen for efficient Mg uptake. Magnesium free Hoagland's solution at one‐fourth strength was used to water the plants as needed. Forage produced was clipped, dried, ground, ashed, and analyzed for Mg and K content. A 2‐fold difference for Mg concentration in the forage existed among the lines. The data indicated that a low K]/Mg] ratio in the plant was indicative of a Mg efficient genotype. The data also suggest that caution should be used in making general nutrient recommendations based on tissue or soil tests without knowing the nutrient requirement of the cultivar.