This evaluation was conducted on mixed annual bluegrass and creeping bentgrass at Mount Washington Resort Golf Club (Bretton Woods, NH) and Val Halla Golf & Recreation Center (Cumberland, ME):
- Bretton Woods, NH - 25% annual bluegrass / 75% creeping bentgrass
- Val Halla, ME - 20% annual bluegrass / 80% creeping bentgrass
Fairways were maintained at a 0.5-inch mowing height. Individual plots measured 3 ft × 6 ft and were arranged in a randomized complete block design with three replications. Fungicides/products were applied based on labeled or suggested rates. Individual treatments were applied at a nozzle pressure of 40 p.s.i using a CO2 pressurized boom sprayer equipped with two XR Teejet 8004 VS nozzles. All products were agitated by hand and applied in the equivalent of 2 gallons of water per 1,000 ft2. Product treatments were put down on either an early application date of 3 November (ME) or 4 November (NH), and a late application date of 9 November (both sites), 2022. Snow mold severity (caused by T. incarnata, T. ishikariensis, M. nivale) was visually assessed as percent snow mold symptoms per plot and turfgrass quality was assessed on a 1-9 scale with 6 being acceptable on March 30, 2023 (ME) and 17 April (NH). Data was subject to an analysis of variance and means were separated using Tukey’s HSD.
At the NH site, snow cover persisted on the experimental plots from November 16, 2022 to April 10, 2023 without complete melt, and high disease severity (68.3%) was observed within untreated plots. The majority of the snow mold damage was caused by Microdochium patch and 10-20% of the damage was caused by T. incarnata and T. ishikariensis. At the ME site, snow cover persisted on the experimental plots from 17to 21 December, 2022 and from 6 January, 2023 until 23 March, 2023 and high disease severity (80.0%) was observed within untreated plots, with the majority of the snow mold damage caused by Microdochium nivale.
Table 1. Snow molds and spring turf quality ratings at Mountain Washington Resort Golf Club, NH (rated on April 17, 2023) and Val Halla Golf & Recreation Center, ME (rated on March 30, 2023) for the 2022-2023 snow mold season.
| Trt# | Treatment and rate per 1,000 ft2 | Application Timingz | Mountain Washington Resort Golf Club, NH | Val Halla Golf & Recreation Center, ME | ||||||
| Snow Moldy | Turf Qualityx | Snow Moldy | Turf Qualityx | |||||||
|
1 |
Untreated |
68.3 |
abw |
3.0 |
c |
80.0 |
abw |
2.0 |
cd |
|
|
2 |
Extreme Green 20 6.0 oz |
Early + Late |
30.0 |
a-c |
4.0 |
a-c |
58.3 |
a-d |
3.0 |
b-d |
|
3 |
Sulfur DF 5.0 oz |
Early + Late |
35.0 |
a-c |
4.0 |
a-c |
75.0 |
ab |
2.7 |
cd |
|
4 |
Duraphite 12 6.0 fl oz |
Early + Late |
40.0 |
a-c |
4.0 |
a-c |
66.7 |
a-d |
3.0 |
b-d |
|
5 |
Duraphite 12 6.0 fl oz + Sulfur DF 5.0 oz |
Early + Late |
55.7 |
a-c |
3.0 |
c |
81.7 |
a-b |
2.0 |
cd |
|
6 |
Potassium bicarbonate 0.8 lbs K20 |
Early + Late |
30.0 |
a-c |
4.3 |
a-c |
90.0 |
ab |
1.3 |
d |
|
7 |
Protone SG 1.35 oz |
Early + Late |
25.3 |
bc |
5.0 |
a-c |
85.0 |
ab |
2.3 |
cd |
|
8 |
ReTain 0.27 oz |
Early + Late |
46.7 |
a-c |
3.7 |
b-c |
78.3 |
ab |
2.3 |
cd |
|
9 |
Zio 6.0 oz |
Early + Late |
30.3 |
a-c |
4.7 |
a-c |
68.3 |
a-c |
2.7 |
cd |
|
10 |
Rhapsody 10.0 fl oz |
Early + Late |
45.3 |
a-c |
4.3 |
a-c |
95.0 |
a |
1.0 |
d |
|
11 |
Civitas pre-mixed 8.5 fl oz |
Early |
31.7 |
a-c |
5.3 |
a-c |
55.0 |
a-e |
3.3 |
b-d |
|
Civitas pre-mixed 34.0 fl oz |
Late |
|||||||||
|
12 |
Primo MAXX 1.0 fl oz |
Early + Late |
70.0 |
ab |
3.0 |
c |
93.3 |
a |
1.3 |
d |
|
13 |
Anuew 0.735 fl oz |
Early + Late |
88.3 |
a |
2.7 |
c |
91.7 |
a |
1.7 |
d |
|
14 |
Enclave 8.0 fl oz |
Late |
31.0 |
a-c |
5.3 |
a-c |
17.3 |
c-e |
6.0 |
a-c |
|
15 |
Enclave 6.0 fl oz |
Late |
2.3 |
c |
6.7 |
ab |
35.0 |
b-e |
4.0 |
b-d |
|
16 |
Enclave 6.0 fl oz + Active 1.5 fl oz |
Late |
2.0 |
c |
7.3 |
a |
12.7 |
de |
6.0 |
a-c |
|
17 |
ProtectMax Tebuconazole 1.0 fl oz + ProtectMax Propiconazole 2.0 fl oz + ProtectMax Chlorothalonil 6L 3.0 fl oz + PAR SG 0.37 fl oz |
Late |
11.0 |
bc |
6.0 |
a-c |
0.3 |
e |
9.0 |
a |
|
18 |
ProtectMax Tebuconazole 1.0 fl oz + ProtectMax Propiconazole 2.0 fl oz + Turfcide 400 4.0 fl oz + PAR SG 0.37 fl oz |
Late |
2.3 |
c |
6.0 |
a-c |
0.7 |
e |
8.7 |
a |
|
19 |
Provision PT 1.0 fl oz + Chlorothalonil 6L 3.0 fl oz + PAR SG 0.37 fl oz |
Late |
9.3 |
bc |
5.7 |
a-c |
0.3 |
e |
8.7 |
a |
|
20 |
ProtectMax Tebuconazole 2.0 fl oz + ProtectMax Chlorothalonil 6L 3.0 fl oz + PAR SG 0.37 fl oz |
Late |
13.7 |
bc |
5.7 |
a-c |
0.0 |
e |
9.0 |
a |
|
21 |
ProtectMax Propiconazole 2.0 fl oz + ProtectMax Chlorothalonil 6L 3.0 fl oz + PAR SG 0.37 fl oz |
Late |
23.7 |
bc |
5.3 |
a-c |
11.7 |
de |
7.0 |
ab |
|
z Days of early and late fungicide application on Nov. 4 and Nov. 9, 2022 on Mountain Washington Resort Golf Club and on Nov. 3 and Nov. 9, 2022 at Val Halla Golf & Recreation Center. y Percentage of plot area exhibiting snow mold symptoms (blighted patches of turfgrass) was reported as the mean of 3 replications. x Turf quality was rated using a 1 to 9 scale (9=best, 6=acceptable) based on color and uniformity and was reported as a mean of 3 replications. W Means followed by the same letter are not significantly different according to Tukey HSD test (α= 0.05). |
||||||||||
In summary, more than two active ingredients are required for acceptable control of multiple snow mold species and on high disease pressure sites.
Submitted by: Dr. Geunhwa Jung and Soonhong Min, Graduate Student, Jung Lab
