Application of nanoparticles (NPs) in the management of plant diseases may reduce the use of pesticides and enhance food security. In this study, the effects of TiO₂ NPs in 100 and 200 mg L⁻¹ concentrations were examined against Meloidogyne incognita (Mi), Pectobacterium betavasculorum (Pb) and Rhizoctonia solani (Rs) under in vitro conditions and in a pot experiment. TiO₂ NPs inhibited the growth of Pb and Rs and significantly reduced the hatching and caused mortality of Mi 2nd stage juveniles. As revealed from the scanning electron microscopy (SEM), TiO₂ NPs react directly to the cuticle/cell wall of test pathogens. In pot experiments, TiO₂ NPs were used as a foliar spray and seed priming. Foliar spray of TiO₂ NPs was found to be more efficient than seed priming in enhancing the growth, activities of defense enzymes, photosynthetic performance, and disease resistance in beetroot. Foliar spray of TiO₂ NPs at 200 mg L⁻¹ resulted in the maximum increase in plant growth, activities of defense enzymes and photosynthetic performance of beetroot. Foliar spray of TiO₂ NPs at 200 mg L⁻¹ caused the maximum reduction in disease indices, nematode multiplication, and root galling. As revealed from the inductively coupled plasma mass spectrometry (ICP-MS) analysis, TiO₂ NPs accumulated across the tissues of both infected and un-infected plants irrespective of the method of application. Overall, the findings show that TiO₂ NPs as foliar spray have the potential to be applied for the management of soft rot, root rot and root-knot disease complex of beetroot.

在植物病害管理中应用纳米颗粒 (NPs) 可以减少农药的使用并增强粮食安全。在这项研究中，在体外条件下和盆栽实验中，研究了浓度为100 和 200 mg L ^-1的 TiO ₂ NPs对南方根结线虫(Mi)、β脉管小杆菌(Pb) 和立枯丝核菌(Rs) 的影响。TiO ₂ NPs抑制了Pb和Rs的生长，显着降低了Mi 2期幼鱼的孵化率和死亡率。由扫描电子显微镜 (SEM) 显示，TiO ₂NPs 直接与测试病原体的角质层/细胞壁发生反应。在盆栽实验中，TiO ₂ NPs 被用作叶面喷雾和种子引发剂。发现叶面喷洒 TiO ₂ NPs 在促进甜菜根的生长、防御酶的活性、光合性能和抗病性方面比种子引发更有效。叶面喷洒200 mg L ^-1 TiO ₂ NPs导致植物生长、防御酶活性和甜菜根光合性能的最大增加。叶面喷洒200 mg L ^-1 TiO ₂ NPs导致疾病指数、线虫繁殖和根部磨损的最大减少。正如电感耦合等离子体质谱 (ICP-MS) 分析所揭示的，无论使用何种应用方法，TiO ₂ NPs 都会在感染和未感染植物的组织中积累。总体而言，研究结果表明，作为叶面喷洒的TiO ₂ NPs 有可能用于管理甜菜根的软腐病、根腐病和根结病复合体。