CFAES
Give Now
Turfgrass Science

College of Food, Agricultural, and Environmental Sciences

Turfgrass Science
https://buckeyeturf.osu.edu

Rolling After Putting Green Fungicide Application

Introduction

Sometimes you get a hunch to try a different management practice, but might not want to try in fear of negative consequences. That’s where turfgrass researchers come in! In spring of 2021, Gary Deters, former golf course superintendent at St. Cloud Country Club (St. Cloud MN) and current field manager for the University of Minnesota (UMN) turfgrass research program had one of those hunches for quite awhile that he wanted to investigate.

Gary and other Minnesota golf course superintendents wondered what the consequences would be if you rolled a putting green directly after it been sprayed with fungicide. Would the fungicide be removed? Would the fungicide be spread better? Would you end up wasting money and get huge disease breakout? This idea came about due to changes in labor availability that has hit the golf course management industry and the need to sometimes do things differently when the need arises.

Results from the trial at UMN in 2021 indicated that when using Secure Action (Acibenzolar-S-methyl, Fluazinam) @ 0.50 fl. oz. per 1,000 sq. ft. there were no apparent negative consequences if the plots were rolled right after spraying (Figure 1).

Figure 1
Figure 1: Drone picture of 2021 trial at University of Minnesota (UMN).

However, there was little to no disease pressure on these plots in 2021 (besides some brown patch outside of the plot area!). Still we could see the effects of the Acibenzolar-S-methyl on fungicide treated plots whether they were rolled or not – these plots were darker green compared to plots not treated with fungicide (Figure 2).

Figure 2
Figure 2: Plots treated with Secure Action were darker green due to Acibenzolar-S-methyl regardless of being rolled after application.

Data for the normalized difference vegetation index (NDVI) also showed that rolling did not remove the Secure Action from the leaves – leading to darker green turf (Figure 3).

Figure 3
Figure 3: NDVI on plots at UMN treated with Secure Action (@ 0.50 fl. oz. per 1,000 sq. ft.) and rolled after treatment or not rolled after treatment. Higher NDVI indicates darker green turf.

It was good to see that the Acibenzolar-S-methyl still was impacting the turf regardless of being rolled or not, but the lack of disease still made us wonder if this management practice was a good idea. Therefore, we have repeated the trial at the Ohio Turfgrass Foundation (OTF) center to see if we could get more disease on this trial.

 

Materials and Methods

The trial was initiated at the OTF center in Columbus Ohio on May 11th 2022 on a native soil bentgrass surface maintained as a putting green. The plot area was mowed at 0.125″ 4-5 days per week and was brushed daily unless under high stress. In July, plots were not mowed first thing in the morning to keep the dew on the plots longer in order to promote dollar spot disease. Primo (trinexapac-ethyl) was applied on June 8th, June 15th, June 29th, and July 11th @ 6 fl. oz. per acre.

Plots were treated with Secure Action (Acibenzolar-S-methyl, Fluazinam) @ 0.50 fl. oz. per 1,000 sq. ft on approximately every 14 days (May 11th, May 27th, June 10th, June 24th, July 7th, and July 22nd). Rolling treatments were applied to non-fungicide treated plots first, and was then applied to fungicide treated plots directly after Secure Action application.

 

Results and Discussion

There was no significant difference in turfgrass quality prior to treatment initiation on May 11th (Figures 4 and 5).

Figure 4 part 1
Figure 4 part 2
Figure 4 part 3
Figure 4 part 4
Figure 4: Plot appearance prior to treatment initiation.
Figure 5
Figure 5: Turfgrass quality of plots prior to treatment initiation.

As of July 27th 2022 results indicate the rolling after an application of Secure Action does not change fungicide efficacy or alter turfgrass quality. Turfgrass quality was significantly increased with Secure Action application, regardless of rolling (Figure 6), and dollar spot disease was significantly  suppressed with Secure Action application, regardless of rolling (Figure 7).

Figure 6
Figure 6: Turfrgass quality on July 27th 2022.
Figure 7
Figure 7: Number of dollar spot disease infection centers on July 27th 2022.

Not only was dollar spot disease significantly suppressed still if Secure Action treated plots were rolled right after, but the simple application of Secure Action lead to improvements in visual quality – noticeable across all replicates (Figure 8).

Figure 8 part 1
Figure 8 part 2
Figure 8 part 3
Figure 8 part 4
Figure 8: Plot appearance on July 27th 2022.

As of now the results indicate that at least with a contact fungicide (though Acibenzolar-S-methyl is systemic) rolling after application does not reduce the effects of the fungicide. This type of management practice could be useful during panic periods when staff is low and fungicide needs applied ASAP in the morning before more workers comes in. In the future, we will examine this further using different products and standard fungicide roations to see what happens when more than contact fungicides are used.

Tags: