The influence of seed maturity at harvest and drying method on the embryo, α-amylase activity and seed vigour in sorghum (Sorghum bicolor (L.) Moench)

Abstract

Seed lots of sorghum cv. IS 34213 were produced by harvesting either at the time of black layer formation on the endosperm (equivalent to maximum seed dry weight) or at full maturity and then dried either slowly under shaded conditions or rapidly in the sun. Small seeds had the lowest viability and vigour in each of the seed lots. Seeds harvested at full maturity were of higher vigour and this was not decreased by the drying method. Low vigour seeds showed the greatest decline in performance after ageing. Low vigour was associated with low initial viability (K i ), low final laboratory germination percentage, a long lag phase before germination, poor seedling performance and a large proportion of non-viable or incompletely vitally stained seed embryos. Alpha-amylase activity in germinating seeds was related to seed vigour.