Isaac Mertz1, Nick E. Christians1 and Marcus Jones2, (1)Iowa State University, Ames, IA (2)Stoller USA Inc., Ankeny, IA
Root production of turfgrass is often used as an indicator of overall plant health as well as a predictor of how the plant will stand up to drought and heat stress. Plants that exhibit a higher amount of rooting are able to tolerate more stress and require fewer resources to maintain. The objective of this research was to evaluate root production of ‘Tyee’ creeping bentgrass (Agrostis stolonifera L.) treated with Root Mass 20/20, a biostimulant and Stimulate, a plant growth promoter. Creeping bentgrass plugs were transplanted into custom made root tubes and allowed to re-establish in a greenhouse before being treated. Treatments included Root Mass 20/20 at 1.18 and 2.32 L ha-1, Stimulate at 0.29 to 0.57 L ha-1, and Root Mass 20/20 plus Stimulate at 0.29 to 0.57 L ha-1. After 56 days of establishment plant parts were harvested, dried, and ashed in a muffle furnace to evaluate rooting production. At 2.32 L ha-1, Root Mass 20/20 increased rooting production 16.3% compared to the untreated control. Plants treated with Stimulate at 0.57 L ha-1 exhibited a 9.1% increase of rooting compared to the untreated control. A combination rate of 0.29 L ha-1 each of Root Mass 20/20 and Stimulate resulted in 11.3% more root production than the untreated control. All other combination rates however resulted in a decrease in rooting production from the untreated control, indicating an inhibitory effect. Creeping bentgrass treated with Root Mass 20/20 and Stimulate can result in increased root production, but the response is rate dependent.