Effects of plant biostimulants on seedling root and shoot growth of three cool-season turfgrass species in a controlled environment

A plant biostimulant is a natural substance or microorganism applied to plants or soil to enhance growth and stress tolerance. The objective of this study was to measure the effect of six commercial plant biostimulants on root and shoot production in seedlings of three cool-season turf species grown in a controlled environment. Lolium perenne L., Agrostis palustris Huds., and Schedonorus arundinaceus Schreb. were seeded into tobacco float trays and, after germination, were installed in a hydroponic system receiving a half-dose Hoagland solution. Fifteen days after seeding, seedlings were treated with six different plant biostimulants applied within each float tray and then grown in a greenhouse for 25 d, following a split-plot design. Photosynthetically active radiation, air temperature, and humidity were monitored for the duration of the study. The experiment was conducted twice. Fresh weight, dry weight, and total nonstructural carbohydrates were measured. The study showed that humic substances and complex organic materials had a positive effect on turfgrass performance, and there are species differences in the responses of turfgrass.