Erik Ervin, Ph.D., associate professor of turfgrass science at Virginia Tech, has been working on seaplant-based biostimulant formulations for improved bentgrass heat tolerance.
While variations of this technology have been around for approximately 20 years, many superintendents are unaware of the possibilities provided by bio-based nutrition. Ervin provided a little background and an update on what has been taking place in the lab.
“My personal description of bio-based nutrition products are those that contain plant, animal, or microbially-based ingredients that are formulated with macro- and/or micro-nutrients with the intention of improving the health and overall performance of the treated turfgrass system,” he says. “Some of the most common bio-based ingredients are: kelp or seaweed extracts, humic substances (humic, fulvic, and ulmic acids), amino acids, vitamins, sugars/carbohydrates (in many forms), bacteria (and their fermentation extracts) and mycorhizal fungi.”
According to Ervin, the growing popularity of the game - and bentgrass playing surfaces - spurred the interest in bio-based nutritional products.
“The real explosion of these products occurred in the late 80s and early 90s with the expansion of the golf market and the push to have faster and faster greens,” he says. “Mowing bentgrass lower and managing it farther and farther south in the United States put extra stress on greens, prompting a physiological phenomena called ‘summer bentgrass decline.’ Trying to get few more days of survival or performance out of your heat-stressed greens opened up this bio-nutrition market, in my opinion.
“It has also been successful as a consequence of our society's push towards wanting practices to be more ‘sustainable,’” he says.
In Ervin’s current research program, he offered several key points:
• Seaweed extracts contain naturally high levels of growth hormones called cytokinins and auxins that we have shown get into the plant and help maintain photosynthetic activity and root viability during heat and drought stress;
• Mixing seaweed extract with leonardite containing humic and fulvic acids has been shown to provide better stress tolerance than using seaweed alone, perhaps due to humic acid's role in more efficient nutrient uptake;
• Supplementing certain amino acids has provided small improvement in rooting and heat tolerance and
• We are currently investigating whether various bacterial packages can improve heat or drought tolerance of cool-season turf.
Ervin points out that bio-based nutrition is not a magic pill and is not a replacement for traditional methods of maintaining healthy turfgrass.
“These programs are not silver bullet or cure-alls,” he said. “The turf manager must first and foremost take care of business by adapting recommended cultural (mowing, irrigating, standard fertilization, etc.) practices and IPM approaches to produce a quality product. Use of bio-based products should be a secondary consideration to try and achieve turf health and performance above and beyond regular expectations or to help pre-condition the turf to get through intense periods of environmental stress.”
As for which turf benefits most from a bio-based program ... it varies.
“Primarily cool-season recreational surfaces that are consistently mowed below their optimum height,” Ervin says. “Warm-season putting greens most likely fit in here also, along with salt-stressed turf areas.”
Worth noting is that Ervin has never seen or documented any agronomic negatives to a bio-based nutritional program.
What does all this mean to golf course superintendents? Ervin offers up sound advice.
“Do your homework; read reports; attend seminars; ask questions; test these products for yourself against blanks,” he says.
As with any technology that is new to a superintendent, it makes sense to talk with those who have taken on this challenge before, he says. The testimonials are out there and the course down the street may have already assumed the “risk” in trying bio-based nutrition.
