Study on suitable seed harvest time of Guicao 1.

The condition of seed -filling and abscission of Guicao 1 was studied during 30 d after its flowering from 2003 to 2005. The results showed that the relationship between 1000-seed weight, abscission rate and days after flowering accords with the logistic theoretical curve, the maximum seed dry weight per ear is at 18～24 d after flowering, the seed germination rate during 15～18 d after flowering is up to 64.3%～91.1% and is no significant difference compared with that at 18～30 d after flowering. The optimum seed harvest time is at 18～21 d after flowering because of its quality seedlings germinated from seeds harvested at 18～21 d after flowering.