Screening herbal extracts as biostimulant to increase germination, plant growth and secondary metabolite production in wheatgrass

Abstract

Recently it has been recognized that herbal plants contain endogenous molecules with biostimulant properties, capable of inducing morphological and biochemical changes in crop plants. Therefore, the present experiment was conducted to screen herbal samples for their plant growth promoting properties. Twenty-five herbal extracts were tested for their biostimulating activity on wheat crop (Triticum aestivum) through seed priming. Morphological parameters chosen for evaluation include: percent seed germination, length and weight of seedling, wheat grass length and biomass. Biochemical parameters include: total phenolic and flavonoid, enzymatic activity of catalase and phenylalanine ammonium lyase and antioxidant activity. Results indicated an increase in the tested parameters by the extracts, however the biostimulant property varied between the selected herbal samples. Some of the samples, such as Phyllanthus emblica, Plumbago zeylanica, Catharanthus roseus and Baccopa monnieri, were highly effective in inducing plant growth promoting parameters. Principal component analysis was performed and herbal samples were grouped into categories based on their activity.