Can essential oils be allelopathic to Lolium multiforum without harming Solanum lycopersicum?

As global demand of agricultural crops for food and fuel increases, the need for exploring eco-friendly biological methods to control weeds and enhance food crop yield is rising. Essential oils can be a safe bio-herbicide with positive effects on food crops. The objective of this experiment was to study the effects of three essential oils on seed germination and radicle length of both a weed, Lolium multiforum (ryegrass), and a common crop, Solanum lycopersicum (tomato). Both plants were exposed to turmeric, ginger, and eucalyptus oils at two different concentrations, and seed germination rate and radicle length were measured on the seventh and tenth days, respectively. We found that treatment with turmeric oil had phytotoxic potential, leading to a reduction in both seed germination and radicle length of ryegrass without a negative impact on the tomato seedlings. Ginger oil possessed allelopathic properties towards ryegrass and tomato, inhibiting seed germination in both. The study highlights that essential oils can be used as eco-friendly bio-herbicides to increase crop yields.