What problems will affect the yield of summer corn?

What problems will affect the yield of summer corn? Please introduce the following factors that affect the yield of summer corn: first, careless seed selection. As the current seed propagation system is not perfect, unqualified maize seeds still account for a large proportion. Some farmers are greedy for bargains and buy so-called improved seeds at low prices from small vendors or informal seed management departments, resulting in a serious reduction in production. Second, the planting density is unreasonable. The high planting density is a prominent problem in the current summer maize production. For example, some farmers plant "Nongda 108", leaving more than 5000 seedlings per 667m2 (1 mu), which is about 1x3 more than the suitable density of this variety. Because the density is too high, the growth and development of single plant is poor, the empty culm rate is high, and the female ear is bald and tipped seriously, resulting in varying degrees of lodging, resulting in reduced yield. Third, fertilization is not scientific. In fertilization, there are widespread phenomena of heavy nitrogen fertilizer, light phosphate fertilizer, ignoring potash fertilizer and micro-fertilizer. Because the crop yield is restricted by the minimum nutrient law. Single excessive application of nitrogen fertilizer can not achieve high yield, on the contrary, it will cause poor lodging resistance, serious diseases and insect pests, resulting in varying degrees of yield reduction. In addition, improper fertilization period and blind application of some effective nutrients (note: the pure content of nitrogen, phosphorus, potassium, medium and trace elements should not be taken into account) too low "corn special fertilizer" will lead to a decrease in yield. Fourth, watering is not timely. The idea of relying on the weather and other rain is serious, often not according to the law of corn water demand to pour "critical water", but in the case of drought to pour "life-saving water", thus seriously affecting the yield. Click to get more corn planting techniques click to get more food crop planting techniques