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Nanopriming with green-synthesized nanoparticles (NPs) has the potential to optimize crop performance under different conditions. This work investigated the implications of nanopriming of maize seeds with green-synthesized Cu-based NPs (ascorbic acid/starch, ACu, and green tea extract, GTCu) on the nutritional and morphophysiological traits of maize plants. Seeds Zea mays cv. Balu 787 were treated with different concentrations (14.5, 29, 58, and 116 mg Cu L–1) of both NPs, compared to hydropriming (CONT) and unprimed seeds (TEST). In a laboratory, seeds were germinated under different water conditions, while the long-term effects of seed nanopriming were evaluated in a greenhouse experiment with plants under different water conditions. The ionomic profile and morphophysiological traits of the plants were evaluated. In germination with water, both NPs increased the seedling Cu content by 37%, while in germination with PEG-6000, ACu and GTCu increased germination by 53 and 131%, respectively, compared with TEST and CONT. Without water restriction, hydropriming and ACu provided higher concentrations of many elements in seedling tissues. Under water deficit, only ACu stood out compared to the other treatments. GTCu promoted nutritional imbalance in both germination conditions. Although both NPs improved the water use efficiency of plants, ACu stood out for providing a better root/shoot ratio, helping the plants to be more tolerant to water deficit. GTCu provided greater shoot growth combined with lesser induction of root growth, leading to higher susceptibility to water deficit. In both experimental conditions, the dose of 58 mg Cu L–1 was highlighted, due to the induction of the greatest effects on seedling/plant development. The results suggest differences in the adsorption/absorption of NPs, with ACu triggering more positive effects on maize plants than GTCu. Overall, this study highlights the potential contribution of green nanotechnology in inducing plant growth and tolerance to abiotic stress by seed nanopriming. [ABSTRACT FROM AUTHOR]

This study aimed to assess the effect of different doses and times of application of the growth regulator trinexapac-ethyl on the productive performance of white oat cultivars. The experiment was carried out in Londrina, Paraná State, Brazil, in the 2019 and 2020 seasons using the white oat cultivars IPR Artemis and URS Corona. The experimental design was a randomized block with four replications arranged in a 4 x 3 factorial scheme, conducted separately for each cultivar, with four doses of trinexapac-ethyl (0, 50, 100, and 150 g ha-1) and three times of application (T1, first node noticeable; T2, first node visible and second node noticeable; and T3, second node visible and third node noticeable). The following agronomic characters were evaluated: plant height, panicle length, panicles per square meter, spikelets per panicle, grains per spikelet, grains per panicle, thousand grain weight,lodging percentage, and grain yield. Application of trinexapac-ethyl at doses of 100 or 150 g ha-1 at T2 or T3 reduced panicle length, spikelets per panicle, and grains per panicle in IPR Artemis and URS Corona. However, it also reduced plant height and increased panicles per square meter and yield in both cultivars. These same doses and times of application resulted in a significant reduction in lodging. [ABSTRACT FROM AUTHOR]