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Tag: bug spray

The Effect of Human Insect Repellents on Perennial Ryegrass (Lolium perenne) Growth and Recovery

The Effect of Human Insect Repellents on Perennial Ryegrass (Lolium perenne) Growth and Recovery

(By Jared Hoyle, KSU Turfgrass Research and Extension and Peyton South, KSU Turfgrass Undergraduate Research Assistant)

Summary. Turfgrass damage has been observed from misapplications of human insect repellents. Minimal research has been conducted to determine the cause of the damage. Greenhouse research trials were conducted to survey various human insect repellents on turfgrass growth and recovery. Insect repellents resulted in a wide range of damage. No common trend was observed although research trial shows possible repellents to be utilized around turfgrass that will minimize turfgrass injury.

Rationale. Human insect repellents containing diethyltoluamide (DEET) commonly damage turfgrass due to non-target application. Common visual damage results in two areas of healthy growing turfgrass in the shape of footprints with necrotic and chlorotic turfgrass surrounding. Damage results in unacceptable turfgrass quality and playability. Minimal research has been conducted to explore the influence of human insect repellents on turfgrass injury and recovery.

Damage from bug spray misapplication to turfgrass.

Objectives. Evaluate the influence of human insect repellants on Perennial Ryegrass (Lolium perenne) growth and recovery.

Study Description. Research trials were initiated in November of 2016 at the Throckmorton Plant Sciences Center Greenhouses in Manhattan, KS to determine the influence of human insect repellents on perennial ryegrass (Lolium perenne) growth and recovery. Perennial ryegrass was established in 10 by 10 cm pots at 387 kg ha-1, maintained at 4.4 cm and were irrigated to prevent drought stress. Greenhouse environment was a 12 hr photoperiod at 15.5°C/ 22.2°C (night/day). Insect repellent treatments were applied to perennial ryegrass plants arranged in a randomized complete block design with 4 replications. Treatments included 9 insect repellents and a non-treated control for comparison (Table 1). Five treatments contained the active ingredient DEET. Other commonly used insect repellents were also included for comparison. Collected data included visual percent injury on a 0%- 100% scale, where 10% represented maximum acceptable injury. Data was subjected to ANOVA in SAS and means were separated according to Fisher’s protected LSD at 0.05 significance level.

Results. All treatments except the control resulted in at least 6% turfgrass injury 1 day after application (DAA). Repel Max (40% DEET) and Off Active (15% DEET) resulted in 68% and 30% injury, respectively 21 DAA. At 21 DAA all other treatments resulted in turfgrass injury similar to the non-treated. Insect repellants with the same active ingredient percentage resulted in various perennial ryegrass injury and recovery. Although no different in % DEET, Off Active and Off Family resulted in 30% and 0% injury, 21 DAA, respectively. Results also demonstrate that permanent non-target turfgrass injury could occur if Off Active and Repel Max are applied as a human insect repellent. Further greenhouse and field trials are needed to confirm results as well as determine if other non-labeled ingredients influence turfgrass injury.

Always remember to READ THE LABEL for the correct rate, turfgrass tolerance, and specific instructions before application!!!

***Mention of trade names or commercial products in this article is solely for identification purposes and does not imply recommendation or endorsement, nor is criticism implied of similar products not mentioned by Kansas State University.***

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What have you been up to? – Undergraduate Research Projects

(By Jared Hoyle, KSU Turfgrass Research and Extension)

As the temperatures start getting warmer, friends and neighbors start getting out more.  So when I run into them, the first question I get is “What have you been up to?”.  Many times people think winter is slow because the grass is not growing but actually during the winter is when we try and get a lot of things done that we don’t have time to get to in the warmer parts of the year.  But one thing that we have been up to is undergraduate research projects.

In the fall of 2016 I had three students come to my office interested in conducting an undergraduate research project.  I told them that the purposes of an undergraduate research projects are; 1. Answer a question for an issue that turfgrass managers face, 2. Learn the process to conduct research and, 3. Relate your research to more than just the turfgrass manager but have a social impact.  All three of them agreed then we started brainstorming and came up with three projects.

Undergraduate Research Project #1 – Student – Peyton South

The Effect of Human Insect Repellents on Turfgrass Growth and Recovery

Ever seen this before? https://www.extension.iastate.edu/turfgrass/blog/dr-nick-christians/mosquito-spray-can-kill-grass

That is what bug spray can do to your turf.  Peyton wanted to look into it more and see if there are differences in not only the bug sprays but if there is recovery. He is currently taking data and we will get that information out there once the project is complete.  Here are some pictures of the project.


Undergraduate Research Project #2 – Student – Dani McFadden

Will Turfgrass Colorants Blemish Clothing?

Dani’s research project was inspired by a question I got from in education event this past year. There has been lots of research on turfgrass colorants and how long they last but what will it do to the clothing of the athletes if they fall.  So Dani went out and applied a variety of different turfgrass colorants, pulled clothing across the colorants (after the recommended drying time) and then analyzed how much colorant blemish the clothing. Once her project is complete then we will be able to determine which products to recommend to athletic field managers so they can rest assure they won’t have any phone calls about stained clothing.


Undergraduate Research Project #3 – Student – Gage Knudson

Prediction of baseball on-base percentage due to infield mowing height

Sometimes there is only a spit second at first base between a baseball batter and the throw at shortstop to determine if the runner is out or safe.  One component of that split second is how fast the baseball moves through the infield.  Holding all other factors constant, Gage manipulated mowing height of a simulated baseball infield to determine the speed of a ground ball hit to the shortstop.  Then he can predict the out percentage at first base.  Gage’s interest in this project not only helps field managers with maintenance of the field but shows how important it is for the coach of baseball team to communicate with the grounds manager.  To simulate a constant speed he used a pitching machine that was aimed at the infield.  Believe it or not that one slit second can be influenced just by the mowing height of the infield.