Effects of Biostimulants on Primary and Secondary Substance Contents in Lettuce Plants

Lettuce (Lactuca sativa L.) is not only easy to grow, but it is also common in diets around the world. This study was conducted to determine the impact of Chinese chive (Allium tuberosum Rottler), soybean (Glycine max L.) leaf, and soybean stem extracts on lettuce plants’ secondary substances, minerals, amino acids, and free sugars. This study was carried out in order to better understand which types of plant extract applications are most effective in increasing lettuce plants’ nutritional value. While not all applications produced an increased nutritional value in the lettuce plants, we found that soybean leaf extract treatments increased the Mg and Ca contents and Chinese chive treatments increased the Fe contents in the lettuce plants. Additionally, glucose and maltose contents in lettuce plants were higher after treatments of Chinese chive and soybean leaf extracts. Finally, all selected extracts increased the total and free amino acid levels in our test plants.