Impact of sonication time in nanoparticle synthesis on the nutrition and growth of wheat (<i> Triticum</i> aestivum L.) plant

Nanotechnology in agricultural applications is promising in improving plant nutrition and yield, pest control, and gene delivery. However, the method to synthesize nanoparticles or nanocomposites (NCs) can play a crucial role in determining the characteristics of NCs, such as size and morphology, which may be critical factors affecting plant nutrition and NCs` potential toxicity. This study elucidates the effect of sonication time in synthesizing NCs on its characteristics and plant use efficiency. For this purpose, a hard/soft nanocomposite (NC) (CoFe 2 O 4 /Ni 0.8 Cu 0.1 Zn 0.1 Fe 2 O 4 ) was sonochemically synthesized at different sonication times (20 and 60 minutes) and comprehensively characterized. They were hydroponically applied to wheat seedlings (50, 100, 200, 400, and 800 mg/L). The physiological, morphological, and nutritional status of the seedlings were determined. The results showed that an increase in sonication time decreased the mean NC size: 26.7 nm (20 minutes) and 17.4 nm (60 minutes). Photosynthetic parameters, growth, and biomass were gradually reduced with the increasing NC concentrations, revealing their toxic effect. However, treating NCs at 60 min significantly improved the average root length, suggesting its beneficial role for plant growth at the germination stage. The content of elements in the composition of the NCs (Fe, Zn, Co, Ni, and Cu) was remarkably higher in the NCtreated roots compared to the untreated controls. In addition, 60 minutes of preparation showed better plant uptake than 20 minutes. This is the first study to evaluate the effect of sonication time in the preparation of NC on plant nutrition and their fate in plants.