Corn, Rice, and Wheat Seed Drying by Two-Stage Concept

Abstract

Corn, rice, and wheat seeds with an initial moisture content (IMC) of 20–25% wb were dried to moisture content below 18% wb at 40–80°C in a fluidized bed dryer (FBD) and spouted bed dryer (SBD) and the seeds with IMC 18% wb were dried to below 14% wb at air temperatures 18–30°C and relative humidity 60–70% by an in-store dryer (ISD). As a result, it appears that a two-stage drying concept is feasible in drying high-moisture-content seeds due to the high germination rate of dried seeds. Nonetheless, the drying temperature must be carefully selected. A drying temperature of 40°C was clearly safe for all samples, whereas more than 90% of wheat seeds still germinated after drying at 60°C in FBD. Furthermore, drying seeds with IMC 18% wb by ISD was safe under specified drying conditions.

Keywords:

• Fluidized bed dryer
• In-store dryer
• Seed drying
• Spouted bed dryer
• Two-stage drying

ACKNOWLEDGMENTS

The authors would like to convey special thanks to the Australian Centre for International Agricultural Research (ACIAR) for the project grant.

Notes

The statistical analysis was done separately for corn, rice, and wheat; so, the superscripts above the mean values of a kind of seed cannot be compared with those of different kinds of seeds.

¹Drying time A = time for drying seed down to ≈18%.

²Drying time B = a value of drying time that is different from drying time A.

The statistical analysis was done separately for corn, rice, and wheat, so the superscripts above the mean values of a kind of seed cannot be compared with those of different kinds of seeds.

N/A = the drying condition could not dry seed to ≤14%.

^a,b Means within a column with the same letter are not significantly different (p < 0.05) by Duncan's Multiple Range Test.