一、块选法块选法又称片选法,是在生长良好、纯度较高、无病虫害的种子田或生产大田,分苗期、抽穗期、成熟期等杂劣最容易区别的时候去杂去劣,将形态上不一致和生长发育不良的植株拔去,留下生长发育良好而且纯一的植株及时收获,混合脱粒,作为大田生产用种。 First, the block selection method Block election method, also known as the chip election method, is growing well, higher purity, no pests or insect pests in the field or field, sub-seedling, heading, maturity and other miscellaneous the easiest time to go Miscellaneous and inferior, the morphological inconsistency and poor growth and development of plant unplug, leaving a good growth and development of plants and a timely harvest, threshing mixed, as the field production of species.