我盟旱地小麦品种,由于多年种植,管理不周,混杂退化程度较为严重,轻的混杂率达10—20%,严重的则高达40—50％。即使是推广年限不长的水地良种,据调查,种籽纯度也只在90％以下。因此良种混杂退化后,对小麦产量和质量部有极大影响。而坚持年年选种的社队,由于品种纯度高,播种质量好,产量能显著提高。如武川县小马莲渠生产队, As a result of years of planting and poor management, the wheat varieties in dryland of our province have a more serious degree of mixed degradation. The light mixture rate is 10-20% and the serious ones are 40-50%. Even the promotion of water is not long-term fine varieties, according to the survey, the purity of the seeds is only 90% or less. Therefore, the deterioration of hybrids after planting, wheat yield and quality of the Department have a tremendous impact. However, the communes and brigades insisting on selecting seeds every year are able to significantly increase their output due to their high purity and good sowing quality. Such as Wuchuan County, Malthus production team,