Abstract
Eggplant (Solanum melongena L.) growth has been reported to be sensitive or moderately sensitive undesirable fluctuations in the environmental conditions resulting from climate changes. Consequently, producing strong eggplant transplants for open fields is needed. A nursery study was implemented in 2018 to evaluate the potential beneficial impacts of nano zinc oxide (n-ZnO) in comparison with conventional zinc oxide (c-ZnO) on growth characteristics, physiological parameters, nutrient contents, and antioxidative activities in eggplant transplants. Foliar application of 200 mg l-1 c-ZnO (cZnO200) significantly increased growth characteristics, leaf relative content of water (RWC), membranes stability index contents, components of non-enzymatic antioxidants (soluble sugars, AsA, free proline, and GSH) and osmoprotectant contents, and antioxidative enzymes (CAT, APX, GR, and SOD) activities comparing with control. Application of 25 mg l-1 n-ZnO (n-ZnO25) showed the same results of all investigated parameters obtained from c-ZnO200 application. Foliar spray of 50 mg l-1 n-ZnO (n-ZnO50) significantly increased all abovementioned parameters compared to other treatments including 100 mg l-1 n-ZnO (showed toxic effect) and the control. Foliar application of n-ZnO50 is, therefore, the best treatment, recommended for producing healthy eggplant transplants for open fields.