Soybean is a strictly self-pollinated crop and crossing between two va-rieties is rather difficult due to small size of flowers and low pod setting (Ram et al., 1981). The crossed pods usually have reduced size and, hence, have fewer seeds/pod. The seeds obtained from the crossed pods may include some seeds that might be due to selfing while crossing.
Ram, Hari Har; Verma, V. D.; Singh, Kamendra; and Pushpendra
"Research Notes : Extent of selfing during crossing in soybean,"
Soybean Genetics Newsletter: Vol. 9
, Article 17.
Available at: http://lib.dr.iastate.edu/soybeangenetics/vol9/iss1/17