ABSTRACT

Seed failures and a premature brown coloration to seeds in bolls from fields in South Carolina in 1999 gave rise to reference to "seed rot" by growers as a new malady in the area. Subsequent research has failed to identify any rot organism in the discolored, empty seed. We will now use the phrase "Hollow Seed" to refer to this malady and have attempted to define its developmental symptoms.

Seed from the cultivar "Maxxa" from fields near Florence, SC, were examined in September, 2002. The hollow seed malady was observed to be the result of abnormally slow growth of the embryo within these seed. Fertilization, which results in formation of the embryo and endosperm, appeared normal. Expansion of the endosperm and spongy parenchyma was normal, so that the seed volume at 20 days post-anthesis (DPA) appeared similar to seed with robust embryos. However, in hollow seed the embryos had not attained sufficient size at 20 DPA to fill the cavity, so that upon collapse of the endosperm, which normally takes place at about 20 DPA, an air gap was created around the embryo. With an air gap separating the embryo and the surrounding spongy parenchyma it was no longer possible for the embryo to receive nourishment and no further growth of the embryo was possible. Thus, the seed remained hollow to maturity.

No physical deformity or anatomical anomaly was observed which could explain this abnormally slow growth of the embryos in these seed.