Aluminum effects on growth, grain yield and nutrient use efficiency ratios in sorghum genotypes

Sorghum (Sorghum bicolor L. Moench) is an important cereal crop of the world. Performance of sorghum in acid infertile soils that are common to the tropics is rather poor. Research was undertaken in greenhouse and field conditions to evaluate the differences in growth, grain yield, and nutrient efficiency ratio (NER) of sorghum genotypes grown at three levels of A1 saturation. The growth of shoots and roots and the grain yields showed significant differences with respect to A1-saturation, genotypes and their interactions. The shoot weights, root weights, and visual scores of the greenhouse study were highly related to grain yields obtained in field. The greenhouse technique adapted in this study appears to be a reliable method for separation of genotypes into A1-tolerant and intolerant types. The NER values helped differentiate genotypes into efficient and inefficient utilizers of the absorbed nutrients. The sorghum entries showed intraspecific genetic diversity in growth and NER values for the essential elements in the presence or absence of toxic levels of A1. We concluded that selection of acid soil tolerant genotypes and further breeding of acid soil (A1) tolerant cultivars is feasible in sorghum.