种植密度和灌溉定额互作对76 cm等行距机采棉生长发育及产量形成影响

【目的】 研究种植密度和灌溉定额互作对棉生长发育特征及产量形成的影响,建立76 cm等行距机采棉种植技术体系。【方法】 采用裂区试验设计,以种植密度为主区,灌溉定额为副区,设置种植密度13.5×10⁴株/hm²(M₁)、18×10⁴株/hm²(M₂)和22.5×10⁴株/hm²(M₃,CK_d),灌溉定额3 150 m³/hm²(W₁)、4 050 m³/hm²(W₂,CK_i)和4 950 m³/hm²(W₃)。研究种植密度和灌溉定额互作对76 cm等行距机采棉生长发育、产量及其构成因素的影响。【结果】 株高随密度和灌溉定额的增加而升高,单位面积叶片数、果枝数、蕾数、花数以及铃数在不同灌溉定额下均以高密度下数量最大。种植密度和灌溉定额对生殖器官质量与营养器官质量的比例(RVR)、单位面积结铃数和籽棉产量有显著的互作效应。植株干物质总重随密度和灌溉定额的增加呈上升趋势,生殖器官质量与营养器官质量的比例(RVR)均在W₁下最大。棉铃生长率(BGR)与群体生长率(CGR)、棉铃生长率(BGR)和群体生长率(CGR)与单位面积结铃数(Boll number)、单位面积结铃数(Boll number)和单位重(Boll weight)与籽棉产量呈显著正相关,在铃期棉铃生长率(BGR)和群体生长率(CGR)与Boll weight呈显著负相关。籽棉产量上M₃W₁、M₂W₂和M₁W₃处理最高,三者无显著差异。【结论】 76 cm等行距与传统(10+66)cm种植模式M₃灌溉定额相同时,76 cm等行距机采棉种植模式单铃重较M₁、M₂密度显著低;降低种植密度能够提高单铃重;降低密度和灌溉定额有利于增加生殖器官质量与营养器官质量的比例(RVR),增加灌溉定额有利于株高和干物质积累量的增加。优化种植密度和灌溉定额能够促进棉株生长,利于产量提高,当种植密度为22.5×10⁴株/hm²,灌溉定额为3 150 m³/hm²时,采用76 cm等行距机采棉种植有利于产量的提高。

Effects of Planting Density and Irrigation Quota on Growth and Development and Yield Formation of 76 cm Equal Row Spacing Machine-Picked Cotton

【Objective】 In order to explore the influence of planting density and irrigation quota on the growth and development characteristics and yield formation of cotton, 76 cm isometric machine-picking cotton planting technology system will be established.【Methods】 This study adopted a split area test design, with planting density as the main area and irrigation quota as the sub-area. Planting densities of 135,000 plants/hm² (M₁), 180,000 plants/hm² (M₂) and 225.000 plants/hm²(M₃) were set. The irrigation quotas were 3,150 m³/hm² (W₁), 4,050 m³/hm² (W₂) and 4950 m³/hm² (W₃). The interaction of planting density and irrigation quota on the growth and development, yield and its constituent factors of 76 cm equal-row cotton harvested was studied.【Results】 Plant height increased with the increase of density and irrigation quota. The number of leaves, fruit branches, buds, flowers and bolls per unit area were the largest under different irrigation quotas at high density. Planting density and irrigation quota had a significant interaction effect on RVR, boll number per unit area and seed cotton yield. The total plant dry matter weight showed an upward trend with the increase of density and irrigation quota, and the RVR was the largest under W₁. Correlation analysis showed that BGR and CGR, BGR and CGR and boll number, boll number and boll weight were significantly positively correlated with seed cotton yield, and BGR and CGR were significantly negatively correlated with boll weight in the boll stage. M₃W₁, M₂W₂ and M₁W₃ treatments had the highest seed cotton yield, and there was no significant difference among the three.【Conclusion】 When the 76 cm equal row spacing is the same as the traditional (10+66) cm planting mode M₃ irrigation quota, the single boll weight of the 76 cm equal row cotton planting mode is significantly lower than that of the M₁ and M₂ densities; Reducing the planting density can increase the single boll and reducing density and irrigation quota can help increase RVR, and increasing irrigation quota can help increase plant height and dry matter accumulation. Therefore, optimizing the planting density and irrigation quota can promote the growth of cotton plants and increase the yield. When the planting density is 225,000 plants/hm² and the irrigation quota is 3,150 m³/hm², 76 cm equal row spacing planting mode is conducive to the increase of the yield of machine-picked cotton.