Abstract In order to investigate the effects of different magnesium (Mg) sources of fertilizers like magnesium sulfate (MgSO4), magnesium oxide (MgO), and magnesium oxide nanoparticles (nMgO) on cotton growth and development, a pot culture experiment was carried out at different concentrations viz., 20, 40, 60, 80, and 100 ppm in factorial completely randomized design (FCRD). From the pot culture studies, 60 ppm of nMgO was found as the optimal dose for improvement in SPAD chlorophyll value, boll weight, and seed cotton yield. Consequently, field experiment was carried out in randomized block design (RBD) with optimized dose of 60 ppm (from pot culture study) of Mg fertilizers like MgSO4, MgO, and nMgO to elucidate their effect on growth, physiological, yield, fiber quality parameters, and nutrient element concentrations in cotton. The treatments were foliar sprayed at vegetative and boll formation stages of cotton similar to pot culture studies. It is confirmed that foliar application of 60 ppm of 50 nm of MgO nanoparticles significantly increased the number of opened bolls per plant (20.6), single plant yield (58 g/plant) and seed cotton yield (1729 kg/ha). The increased seed cotton yield of 42.2, 39.9, and 24.8% was recorded by nMgO, MgO, and MgSO4 over control. Besides, fiber quality parameters like fiber length and fiber strength of cotton were improved by MgO nanoparticles than sulfate form of Mg fertilizers. Moreover, significant and positive influence was achieved by foliar nutrition of MgO nanoparticles on macronutrients like nitrogen (N), phosphorus (P), potassium (K), and Mg concentration in cotton plants.

中文翻译：

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叶面喷施氧化镁纳米颗粒对棉花营养元素浓度、生长、生理和产量参数的影响

摘要 为研究硫酸镁（MgSO4）、氧化镁（MgO）和纳米氧化镁（nMgO）等不同镁（Mg）源对棉花生长发育的影响，在不同的浓度，即 20、40、60、80 和 100 ppm 在析因完全随机设计 (FCRD) 中。从盆栽研究中，发现 60 ppm nMgO 是改善 SPAD 叶绿素值、铃重和籽棉产量的最佳剂量。因此，在随机区组设计 (RBD) 中进行了田间试验，其中 MgSO4、MgO 和 nMgO 等镁肥料的优化剂量为 60 ppm（来自盆栽研究），以阐明它们对生长、生理、产量和纤维质量参数的影响, 以及棉花中的营养元素浓度。类似于盆栽研究，在棉花的营养和棉铃形成阶段进行叶面喷洒。经证实，叶面喷施 60 ppm 的 50 nm MgO 纳米颗粒显着增加了每株植物的开铃数 (20.6)、单株产量 (58 g/株) 和籽棉产量 (1729 kg/ha)。与对照相比，nMgO、MgO 和 MgSO4 记录的籽棉产量增加了 42.2%、39.9% 和 24.8%。此外，与硫酸盐形式的镁肥料相比，纳米氧化镁改善了棉花的纤维长度和纤维强度等纤维质量参数。此外，MgO 纳米颗粒的叶面营养对棉花植株的氮 (N)、磷 (P)、钾 (K) 和镁浓度等常量营养素产生了显着的积极影响。