| dc.description.abstract | Sorghum (Sorghum bicolor L. (Moench) is an important food security crop in sub-Saharan Africa. Its
production on acid soils is constrained by aluminium (Al) stress, which primarily interferes with root
growth. Sorghum cultivation is widespread in Kenya, but there is limited knowledge on response of the
Kenyan sorghum cultivars to aluminium stress. The aim of the study was to identify and
morphologically characterise aluminium tolerant sorghum accessions. The root growth of three
hundred and eighty nine sorghum accessions from local or international sources was assessed under
148 μM Al in soaked paper towels, and 99 of these were selected and further tested in solution. Ten
selected accessions were grown out in the field, on un-limed (0 t/ha) or limed (4 t/ha) acid (pH 4.3) soils
with high (27%) Al saturation, and their growth and grain yield was assessed. Although the Al stress
significantly (P ≤ 0.05) reduced root growth in most of the accessions, there were ten accessions;
MCSRP5, MCSR 124, MCSR106, ICSR110, Real60, IS41764, MCSR15, IESV93042-SW, MCSRM45 and
MCSRM79f, that retained relatively high root growth and were classified as tolerant. The stress
significantly (P ≤ 0.05) reduced seedling root and shoot dry matter in the Al-sensitive accessions. Plant
growth and yield on un-limed soil was very poor, and liming increased grain yield by an average 35%.
Most of Kenya sorghums were sensitive to Al stress, but a few tolerant accessions were identified that
could be used for further breeding for improved grain yield in high aluminium soils. | en_US |
