Root Growth Promoting Benefit of Bayer SignatureTM XTRA Stressgard®.

Intensively managed creeping bentgrass (agrostis stolonifera L.) golf course putting greens are prone to various kinds of stress during summer months. Abiotic stress suppresses physiological activities and reduces growth. This in turn, weakens plants and renders them vulnerable to biotic stresses including fungal diseases. While managing both biotic and abiotic stress is crucial for maintaining cool-season turf quality during summer heat, traditional fungicide programs focus on the former. Signature^TM XTRA Stressgard^® is a systemic fungicide that protects and promotes plant health by preventing and supporting recovery from oxidative stress on turfgrasses. While its benefit of improving plant performance during summer heat have been well documented in field trials, this study sought to demonstrate its benefit in promoting root growth under stressful conditions using solution culture to visibly monitor rooting over time. ‘Proclamation’ creeping bentgrass plugs were sampled from a USGA specification putting green at Clayton, NC. Plant material was transplanted into a custom-made solution culture system inside a greenhouse after removing existing roots. Following an acclimation period (32/21°C day/night rootzone temperature), plant materials were treated with Signature^TM XTRA Stressgard^® at rates of 0.61 and 1.22 g/m² (2 and 4 fl oz/1000 ft²) on 7d and 14d intervals, respectively. With canopy heights maintained at putting green height and nutrient solution replaced every 7d, root regrowth was assessed at the end of 7wk. Visual assessment revealed enhanced root length and density in Signature Xtra Stressgard treated plugs compared to nontreated plugs. Total root dry mass confirmed that Signature^TM XTRA Stressgard^® treated plugs at 7d and 14d apart resulted in 33 and 38% more root growth compared to the nontreated control. Our results demonstrate the root growth promoting benefit of Signature^TM XTRA Stressgard^® in a quantitative and visual manner.