在生产饲料作物种子时,植物育种学家在单季收获区设法压缩生育期以扩大生产,从而最大限度地提高产量。这在温带饲料作物生产中已取得辉煌成就。至于蔬菜及特种花卉种子生产,植物育种学家面临一个问题,即不得不连续提供切花并保证盛花期于陈列期的需要,这些导致一个较长的种子生产适宜期。换言之,他们不能选择和培育花期一致的花卉品种。这就意味着农民只得分别手工收获种子。这在劳力较低廉的发展中国家是一种较普遍的现象,然而在劳力昂贵的发达国家只得进行机械收获。在这种情况下,种子穗部熟期的不同及后期种子壳的破裂从而 Plant breeders are trying to squeeze the growing season in single-season harvested areas to produce more of the fodder crop, maximizing production. This has made brilliant achievements in the production of temperate forage crops. As for the production of vegetables and special flower seeds, plant breeders face the problem of having to provide cut flowers in succession and to ensure the full flowering period during the display period, which leads to a longer suitable period for seed production. In other words, they can not choose and cultivate the same flowering species. This means that farmers have to separately harvest the seeds by hand. This is a more common phenomenon in developing countries with lower labor costs, but only in developed countries that are labor-intensive and expensive. In this case, the difference in maturity of the seed panicle and the rupture of the seed shell later