Soybeans, field beans, and other large seeded legumes are especially vulnerable to rough treatment. The seed coat, or testa , of these seeds is very thin and easily cracked. In addition, the plumule and radicle , parts of the seed embryo , are just under the seed coat and can easily be bruised by rough handling. Because they are dicotyledons , these plants can easily be broken in two. Injury to seed from mechanical abuse, harvest, processing, and handling can seriously affect the germination, establishment, and ultimately yield of the subsequent crop.
Special care is taken when harvesting and processing soybeans and field beans used for seed.
The seed is never allowed to fall more than a foot anywhere in the cleaning, packaging, and storage operations. The elevators and buckets used to transport the seeds are covered in rubber and plastics to dampen seed impact against otherwise hard steel surfaces. Once the seed has been sold it is up to the farmer or gardener to make sure that the seeds are treated with care. The following is a demonstration of the hypochlorite soak test used to determine if soybean seed coats have been cracked due to excessive handling. The test is primarily used during harvest to help reduce mechanical damage due to combining and seed handling.