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山东省潍坊市近年来玉米产量提高较快,1984年全市420万亩夏玉米平均亩产726斤,玉米获得较高产量的基本经验是:在改善肥水条件的基础上,选用良种,实行套种,调整种植规格,进行合理密植,扩大叶面积,增多亩穗数以夺取高产。几年来的玉米生产实践反复证明,一般生产条件下,在亩穗数、穗粒数和粒重这三个产量构成因素中,以亩穗数和亩产量的关系最为密切,产量的增加首先是由于亩穗数增加的结果。而玉米是分蘖性极弱的作物,不能依靠分蘖成穗,亩穗数的增加直接取决于亩株数的增多,要想增加穗数就必须增加株数。因此,根据生产条件、品种特性和管理水平,因地制宜地增加株数,进行合理密植就成为当前提高玉米产量的一个关键措施。在增加密度的情况下,空秆率和小株率显著增加,从而使植株整齐度下降,影响产量的进一步提高。据调查,在相同条件下,不整齐的玉米和整齐的玉米比较亩产量可差250—300斤,并且凡是出苗不整齐
In recent years, Weifang City, Shandong Province, corn production increased rapidly in 1984, the city’s 420 acres of summer maize average yield of 726 pounds, the basic experience of corn to obtain higher yields are: on the basis of improving fertilizer and water conditions, the selection of elite, interplanting, Adjust planting specifications, conduct close planting density, expand leaf area, increase the number of acres of spikes in order to capture high yield. Over the past few years of corn production practice has repeatedly proved that under normal production conditions, the number of acres per spike, grain number and grain weight of the three yield components, the number of acres per mu yield and the most closely related to the increase in production, first of all As a result of the increase in acres of spikes. The corn is extremely weakened crops, can not rely on tillering into ear, the increase in the number of acres directly depends on the number of acres of plants increased, in order to increase the number of spikes must increase the number of plants. Therefore, according to the production conditions, variety characteristics and management level, according to local conditions to increase the number of plants, to conduct close planting density has become a key measure to increase corn production. In the case of increasing density, the empty stalk rate and small plant rate increased significantly, which led to the decline of plant uniformity, affecting the further increase of yield. According to the survey, under the same conditions, less tidy corn and tidy maize than the yield of 250-300 pounds per kilogram, and all the irregular emergence