Ultrasound Prototype for Improving Germination and Seedling Growth in Tomato and Maize Seeds

The optimization of germination rates and seedling performance is of utmost importance in the agricultural practices. Ultrasound treatment have emerged as a promising technique for seed treatment due to their efficiency and eco-friendliness, but improvements and optimizations are still needed to meet the demands of industrial sector. Here, the optimization and performance of a prototype sonicator was tested on four economically important seed species (tomato, turnip, maize, and watermelon) subjected to 19.8 kHz of frequency and a power output of 200 W. The ultrasound effects and the optimal sonication time varied among the seed species, resulting in significant stimulations in tomato, turnip and maize. In tomato and maize, the sonication consistently stimulated the germination and seedling development: increased the germination percentage (43 and 20%, respectively) and reduced the mean germination time (19 and 17%, respectively); increased the seedling emergency percentage (41% in maize) and reduced the mean emergency time (10 and 7%, respectively). Measurement of the seedling vigor index revealed a remarkable stimulation in tomato, turnip, and maize (up to 121%), reflecting a stimulation in both seedling height and biomass gain of turnip (121 and 188%, respectively) and maize (26 and 23%, respectively). Bivariate correlation rank coefficients showed strong positive correlations between different germination and seedling growth parameters for all tested species. The promising results of sonication on seed germination and seedling growth in tomato, maze and turnip emphasizes the technology's immense potential within the seed industry and might lead to the enhancement of agricultural productivity and sustainability in the near future.