Sorghum genotype differences in uptake and use efficiency of mineral elements

Summary

Twelve sorghum [Sorghum bicolor (L.) Moench] genotypes consisting of hybrids, varieties from tropical and temperate regions, and land races of India and West Africa were evaluated for mineral element uptake from the soil, efficiency of dry matter production per unit of element absorbed, and efficiency of mineral element transfer from vegetative parts to the grain. The genotypes were grown on an Alfisol in India during a normal rainy season under five levels of applied N (0 to 100 kg ha ¹) and P (0 to 26 kg ha⁻¹). At physiological maturity, grain and aboveground vegetative parts were analyzed separately for N, P, K, S, Mg, Si, Cl, Ca, Al, Mn, Fe, Cu, and Zn.

Genotype x fertility interactions were low indicating that genotypes could be evaluated for uptake and efficiency at various levels of soil fertility. Differences among genotypes to each element were noted for each of above mentioned traits. No genotype showed high efficiency for dry matter production per unit element absorbed for each element, but the West African cultivar Naga White showed highest efficiency relative to five mineral elements. Genotypes varied extensively in their ability to translocate different mineral elements from the vegetative parts to the grain. Except for Naga White, the degree of translocation of mineral elements and harvest index were highly correlated. Genotypes excelling in individual mineral element uptake or use efficiency were generally the land races with lower grain yields and lower translocation efficiencies. Thus, a future challenge is to combine desirable mineral element traits into specific few sorghum lines for improvement purposes.