Effect of Bean Ladder Usage on Mechanical Damage During Soybean Seed Conditioning

Post-harvest soybean [Glycine max (L.) Merr.] seed conditioning operations can inflict mechanical damage to the seed. The objectives of this study were to 1) quantify the amount of mechanical damage at each impact point during seed conditioning and 2) evaluate the effect of the bean ladder in minimizing mechanical damage and improving seed quality during conditioning. Soybean seed from a single seed lot of cultivar H6686 were loaded into two storage bins) one with a ladder and the other without a ladder. Seed were sampled at five stages during receiving and nine stages during cleaning and bagging and evaluated for moisture content, germination, and percentage of cracked seed coats (CSC). The seed in the bin filled with the bean ladder had a significantly lower proportion of CSC and significantly higher germination than seed in the bin without a ladder. Seed sampled from the bin without the ladder had a consistently higher percentage of CSC at most drop heights; however, the difference was significant only at the greatest height, 25.1 m. Seed sampled from the bin with the ladder exhibited significantly higher germination than seed from the bin without the ladder at drop heights of 16.8 m or greater. Seed removed from the bin with a ladder had significantly higher germination at the end of the cleaning and bagging phase than the seed from the bin without a ladder. The bean ladder helped reduce mechanical damage during the receiving phase and maintained a higher level of seed quality at the end of the cleaning and bagging phase compared to the bin without a ladder.