Novel intra-boll yield component traits and fiber quality indices have been used by breeders to select suitable Gossypium hirsutum L. lines, but there is little research on how these traits change during cultivation practices, especially fertilizer application. We hypothesized that these novel traits have obvious responses to phosphorus (P) fertilizer, which would explain the variation in yield and fiber quality under different P conditions. To address this hypothesis, a field test was conducted with a low-P sensitive cotton cultivar (Lu 54) and a low-P tolerant cotton cultivar (Yuzaomian 9110) under different P fertilizer rates (0 as control, 100, and 200 kg P₂O₅ ha⁻¹) from 2016 to 2018. The results showed that P fertilizer application (100, and 200 kg P₂O₅ ha⁻¹) increased the lint yield, and bolls per ha contributed most to the increase in lint yield, followed by boll weight and lint percentage. The increased bolls per ha under P fertilizer application was due to the accelerated process of boll forming and the slowing of shedding process. The increased boll weight under P fertilizer application could be explained by the higher seed biomass per boll and fiber biomass per boll, especially the latter. The higher seed biomass per boll was due to the increased seeds per boll, and higher fiber biomass per boll should be attributed to the increased fibers per seed under P fertilizer application. The positive contribution of lint percentage to lint yield formation under P fertilizer application could be attributed to the increased fiber biomass per seed. P fertilizer application decreased fiber micronaire, indicating that fiber thickness was decreased by extra P fertilizer, which might be associated with the negative effects of increased fibers per seed and fiber density. In addition, P fertility application promoted the elongation of fiber cells and fiber length uniformity, and increased fiber strength. The end result was an increase in the comprehensive fiber quality index (Q-score) after P application. Moreover, compared to Yuzaomian 9110, yield traits including lint yield, bolls per ha, seeds per boll, seed index, and SSA, and quality indices including fiber length, fiber strength, and Q-score were more sensitive to P fertilizer application in Lu 54.

育种者已经使用新的铃内产量成分性状和纤维质量指数来选择合适的陆地棉品系，但很少研究这些性状在栽培实践中如何变化，尤其是施肥。我们假设这些新性状对磷（P）肥有明显的反应，这可以解释不同磷条件下产量和纤维质量的变化。为了解决这个假设，在不同的磷肥施用量（0 作为对照、100 和 200 kg P ₂ O ₅公顷^-1) 从 2016 年到 2018 年。 结果表明，施磷肥（100 和 200 kg P ₂ O ₅ ha ^-1) 增加了皮棉产量，每公顷棉铃对皮棉产量的增加贡献最大，其次是棉铃重量和皮棉百分比。施磷肥每公顷棉铃数增加是由于棉铃形成过程加速和脱落过程减慢。施磷肥下的铃重增加可以解释为每铃种子生物量和每铃纤维生物量较高，尤其是后者。每铃较高的种子生物量是由于每铃种子增加，而较高的每铃纤维生物量应归因于施用磷肥时每粒种子的纤维增加。在磷肥施用下，皮棉百分比对皮棉产量形成的积极贡献可归因于每粒种子纤维生物量的增加。施磷肥降低了纤维马克隆值，表明额外的磷肥降低了纤维厚度，这可能与增加每粒种子纤维和纤维密度的负面影响有关。此外，施磷肥促进了纤维细胞的伸长和纤维长度的均匀性，增加了纤维强度。最终结果是施用磷肥后综合纤维质量指数（Q-score）增加。此外，与玉早棉9110相比，鲁省的皮棉产量、每公顷铃数、每铃种子数、种子指数和SSA等产量性状以及纤维长度、纤维强度和Q值等品质指标对磷肥的施用更为敏感。 54. 施磷肥促进了纤维细胞的伸长和纤维长度的均匀性，增加了纤维强度。最终结果是施用磷肥后综合纤维质量指数（Q-score）增加。此外，与玉早棉9110相比，鲁省的皮棉产量、每公顷铃数、每铃种子数、种子指数和SSA等产量性状以及纤维长度、纤维强度和Q值等品质指标对磷肥施用更为敏感。 54. 施磷肥促进了纤维细胞的伸长和纤维长度的均匀性，增加了纤维强度。最终结果是施用磷肥后综合纤维质量指数（Q-score）增加。此外，与玉早棉9110相比，鲁省的皮棉产量、每公顷铃数、每铃种子数、种子指数和SSA等产量性状以及纤维长度、纤维强度和Q值等品质指标对磷肥的施用更为敏感。 54.