Hard and impermeable seeds in soybean, as in other grain legumes, are of common occurrence. Various workers have studied this trait in soybean and attributed it to both genetical (Woodworth, 1933; Green and Pinnell, 1968; Kilen and Hartwig, 1978; Srinives, 1980; Srinives and Hadley, 1980; Rana et al., 1981; Shahi and Pandey, 1982) and environmental (Archavaleta and Snyder, 1981; Gupta et al., 1981, 1982) factors. Shahi and Pandey (1981) found association of hard seeds with lateness in flowering and maturity.
Rana, N. D.
"Research Notes : India : Retention of impermeability and viability of soybean seeds under water submergence,"
Soybean Genetics Newsletter: Vol. 12
, Article 14.
Available at: http://lib.dr.iastate.edu/soybeangenetics/vol12/iss1/14