6/28/2022 - By John Keeler

There is a high demand for turfgrass perfection on a golf course, especially during the busy summer season. This expectation to maintain peak playing conditions, whatever the weather, takes its toll on golf course superintendents and greenskeepers, especially when summer disease is on the rise.

To support healthy, strong turfgrass that can withstand extreme summer weather, and stand up to the highest standards, you will need to use every tool in your toolbox.

Temperature and Plant Growth Regulators

We can expect high disease pressure over the next two summer months.

However, you may be able to alleviate the situation by making a practical decision to shorten your spray intervals. Tighter applications of fungicides and biostimulants can help suppress diseases and stimulate growth during stressful summertime conditions.

An interesting article was published by Dr. Jeff Beasley and Dr. Bruce Branham (2005a). It showed that Plant Growth Regulator (PGR) breakdown (metabolism) was directly related to air temperature. As air temperature increases, the rate of breakdown also increases. From this research, it is clear that temperature needs to be accounted for when planning out PGR applications. 

We also know grass species and mowing height/frequency impact PGR duration, but those factors don’t change like air temperature. If we assume the same holds true for fungicide metabolism (such as Harrell's ProtectMAX® Title Phyte®), shortening preventative spray intervals during the summer months should be more effective and should lessen disease severity.(d)

However, don’t rely on fungicides alone for disease control. Avoid using turfgrass varieties that are susceptible to common diseases and follow best practices for cultural disease-management to reduce selection pressure on the fungus.

Biostimulants

High summertime temperatures can cause the roots of many grass varieties to shorten and even die during the summer. Fortunately, regrowth does occur at the onset of the cooler autumn weather. Regardless of how it may seem, some steps can be taken to limit and even prevent severe damage. The use of biostimulants can assist in times of stress and will encourage rooting. By using biostimulants as a part of your management program, the turf can become a dense, healthy stand that offers many aesthetic, recreational, and environmental benefits.

Biostimulant Research

(b) Dr. Richard Schmidt, Emeritus Professor of Turfgrass Science at Virginia Tech, is considered the pioneer of research on turfgrass biostimulants. He once wrote that: “Biostimulants are organic materials that, when applied in small quantities, enhance plant growth and development.” The term, “biostimulant,” covers a wide range of products including plant hormones, humic and fulvic acids, seaweed extracts, amino acids and microbial inoculants. 
(c) Dr. Ervin (Univ of Delaware) and Dr. Zhang (Virginia Tech) also showed that combining Humic acid + Seaweed Extract can supply better plant health during stressful conditions than using either one alone. There are many products that are beneficial to plant or soil health and choosing the right material for your specific plant needs is important.
Harrell’s is here to help.

Our Team conducts turf trials throughout the United States to find products and combinations that work and create a Balanced Approach.

Harrell's Balanced Approach is a unique strategy that addresses all aspects of turfgrass health and fertility. There is no one-size-fits-all solution for turfgrass management. However, we can harness proven products and processes to create a tailored agronomic program. If you need help in developing your perfect program or diagnosing your turf, reach out to your local Harrell's representative.

1. https://sportsfieldmanagementonline.com/2019/08/06/update-on-primo/10633/
2. https://sportsfieldmanagementonline.com/2015/06/23/a-perspective-on-biostimulants-and-sportsturf/7193/
3. https://www.biostimulant.com/biostimulants-and-plant-health-products-for-turf-systems/
4. http://www2.ca.uky.edu/agcomm/pubs/PPA/PPA1/PPA1.pdf