If the quality of small and larger seeds were similar, economic loss in seed business would be minimized as small
seed or off size seed can be used in plant production. The objective of this experiment was to study the effects of seed size on
seed quality and seedling growth of maize. This experiment was conducted at Seed Processing Plant, Faculty of Agriculture,
Khon Kaen University. Three sizes, large medium and small, of maize seeds variety SPP339 and SPP999 were obtained by
sieving the seeds through screens of different diameters of 20/64, 16/64 and 14/64 inch. Seed quality was subsequently tested.
The results revealed that, seed germination of the large seed size did not differ from medium size and small size. However,
there was a trend that small seeds germinated faster. Seed vigor assessed by accelerated aging test revealed that small seed size
had a lower germination percentage than other seed sizes. Seedlings of large seed had seedling dry weight, seedling height and
number of seminal roots more than those of medium and small seed size. However, large seeds tended to have shorter
rootlength but developed faster as leaves were fully expanded faster than the seedling from medium size and small size.