氮肥与缩节胺对机采棉生长发育及氮素分布的影响

【目的】研究新疆机采棉田合理的施肥化控配套技术。【方法】采用双因素裂区试验设计，以新陆中88号为材料，设置3个纯氮水平(160、320、480 kg/hm²)及3个缩节胺剂量(189、280.5、372 g/hm²),分析氮肥与缩节胺对机采棉农艺性状、干物质积累与分配、氮素吸收及产量的影响。【结果】随施氮量增多，棉花生育时期滞后，喷施缩节胺可以提前棉花生育时期；随施氮量增多，棉花株高、倒四叶宽、茎粗、株高日增量、干物质总量增加，喷施缩节胺可以降低株高日增量、倒四叶宽及果枝数，增加生殖器官干物质占比。各施氮量下的氮素积累总量差异显著，N₂较N₁提高66.4%、较N₃提高12.3%;氮肥与缩节胺对籽棉产量存在极显著的互作效应，N₂水平下籽棉产量较N₁提高21.6%,较N₃提高14.8%,N₂H₂处理较N₂H₁、N₂

Effects of nitrogen fertilizer and DPC on the growth and nitrogen distribution of machine-picked cotton

【Objective】In order to explore reasonable fertilization and chemical control supporting technologies for Xinjiang mechanically harvested cotton fields.【Methods】This experiment adopted a two-factor split zone test design, using Xinluzhong No. 88 as the material, and setting 3 levels of pure nitrogen (160, 320, 480 kg/hm²) and three doses of DPC (189, 280.5, 372 g/hm²) were used to study the effects of nitrogen fertilizer and DPC on the agronomic characteristics, dry matter accumulation and distribution, nitrogen absorption and yield of machine-harvested cotton.【Results】The test results showed that with the increase of nitrogen application rate, the growth period of cotton lagged behind, and DPC could advance the growth period of cotton; with the increase of nitrogen application rate, cotton plant height, reciprocal fourth leaf width, stem thickness, daily increment of plant height, and total dry matter increased. Spraying DPC could reduce the daily increment of plant height, the width of the reciprocal fourth leaf and the number of fruit branches, and increased the proportion of dry matter in the reproductive organs. The total amount of nitrogen accumulation under each nitrogen application rate was significantly different. N₂ was 66.4% higher than N₁ and 12.3% higher than N₃; nitrogen fertilizer and DPC had a very significant interaction effect on seed cotton yield. Under the N₂ level, the yield of seed cotton increased by 21.6% compared with N₁ and 14.8% compared with N₃. Compared with N₂H₁ and N₂H₃, the number of bolls per plant in N₂H₂ treatment increased by 5.6% and 3.6%, and the single boll weight increased by 5.6% and 11.8%.【Conclusion】In summary, N₂H₂ treatment accounts for the most reasonable proportion of dry matter in reproductive organs, and bud and boll nitrogen absorption occupies a high proportion, so flowers and bolls are high, thus leading the highest yield of cotton seeds, suggesting it is the most suitable combination of nitrogen fertilizer and DPC in southern Xinjiang.