洋葱大株留种是指从种子→鳞茎→种子的繁种过程，其间经过了一次无性繁殖过程，本质上不同于小株留种，即直接从种子到成株后收获种子，从而最大限度的保证了作物的种性遗传。其次大株留种过程中养分积累较充分，产量可比小株留种提高３０％左右。根据笔者经验，现将洋葱... Onion large plant species is from seeds → bulbs → seed breeding process, during which after a vegetative reproduction process, essentially different from the small plant species, that is, directly from the seeds to adults after harvest seeds, so the maximum Ensure that the crop’s genetic inheritance. Second, the accumulation of nutrients in the process of large strains accumulate more fully, the yield can be increased by about 30% than that of the small ones. According to my experience, now onion ...