2011/2012 Turf Screen Winter Independent Evaluation
Posted on July 18, 2013
Impact of Turf Screen on Winter Time Canopy Temperature, Color, Quality and Early Spring Dollar Spot
Turfgrass Disease Solutions, LLC
Steven McDonald, M.S. and Rick Grala
This trial was conducted on a practice green at Gilbertsville Golf Club located in Gilbertsville, PA. Plots were 25 square feet and treatments were replicated four times in a randomized complete block design. Treatments were applied once on 25 November 2011. Weather at the time of application was 55˚F and the canopy was dry. Following application canopy temperatures were taken biweekly throughout the trial period using a hand held infrared temperature gun. The gun was held at a consistent height. The ambient air temperature was also recorded and is shown in the table. Turfgrass quality was rated on a 0-10 scale where 7= acceptable quality and 10= optimal. Turfgrass color was rated on a 0 to 10 scale where 5= color of untreated control plots and any rating above 5 indicates a increase in color. Dollar spot infection centers were observed late in the trial period and were counted per plot. Data were subject to ANOVA using ARM and significantly different means were separated.
Canopy temperatures were taken 13 times throughout the course of this trial. There was no significant differences in canopy temperature observed. On select rating dates, there was small trends to discuss. For example on 23 February 2012; the untreated plots averaged 55.85˚F, plots treated with Turf Screen alone at 1.7 fl oz/M and 3.4 fl oz/M averaged 56.95 and 57.49, respectively. However, the opposite trend was observed 22 March. Canopy temperature can be extremely difficult and inconsistent to quantify due to drastic differences in cloud cover and wind speeds.
Quality was rated 11 times throughout the trial period. Generally all plots that received Turscreen alone or in combination with fungicides had improved quality for 101 days following application. The highest level of quality differences were observed in January with plots treated with Turf Screen tank mixed with Instrata and those plots had the highest quality, which was significantly better than Instrata alone but similar to all other plots treated with Turf Screen.
The color data also indicate that Turf Screen can improve wintertime color when compared to fungicides alone and untreated turf. The color improvements lasted 101 days following application. It is important to note that this green was not mown following the application (November) until the week of 17 March. Therefore, it is likely that the pigment persisted on the unmown tissue for the duration of the improvement. Other unknown physiologically process may have occurred but it is impossible to determine what these were with a basic field trial such as this. Following mowing much of the pigment was likely removed, hence a decrease (similar to untreated plots) in the color rating among Turf Screen treated plots. These data suggest that mixing Turf Screen with late season applications may aid in color retention through winter months. The winter of 2012 was remarkably mild. Future trials should evaluate Turf Screen in more severe winters such as long periods of snow cover. It would also be important to evaluate Turf Screen at spring green up for its potential improvement in spring time quality and color.
Dollar spot formed early in the 2012 spring due to the fact that no fungicide had been applied in the autumn of 2011 leading up to the trial and unseasonably warm weather in mid to late March. No significant differences were observed on 5 March, however by 22 March the untreated plots had higher levels of dollar spot when compared to Instrata applied alone.