Nick E. Christians and Luke Dant
The purpose of this study was to evaluate weed control and turf phytotoxicity of Scotts Turf Builder with Plus 2 Weed Control to other competitive granular broadleaf herbicides. The research was conducted at the Iowa State University Turfgrass Research Facility on 'Park' Kentucky bluegrass.
The trial design was a randomized complete block. The plots were 10 ft x 5 ft and each treatment was replicated 3 times. The Scotts Company provided all products and each product was applied per the instructions on the label. The application was made when dandelions were flowering but before they had produced "puff-balls". All treatments were applied on May 14 while there was still dew on the weed foliage. All products were applied using 'shaker dispensers'. The soil on the area is a Nicollett (fine-loamy, mixed, mesic Aquic Hapludoll) with 4.6 % organic matter, 6 ppm P, 169 ppm K, and a pH of 7.05.
Weed phytotoxicity was reported two weeks after application on June 28. This was reported on a percent scale, 0% being no damage and 100% being dead. Dandelion and clover cover was recorded 4 and 8 weeks after application on June 11 and July 9. These data were reported on a percentage basis with 0% meaning there were no weeds present and 100% meaning the entire plot was covered by weeds. Turf Quality was taken 2, 4 and 8 weeks after application on a scale of 9-1 (9 = Excellent, 6 = Acceptable, 1 = Worst).
Data were analyzed using Statistical Analysis System and the Analysis of Variance procedure. Treatments effects were tested using the Least Significant Difference (LSD) test.
Weeds treated by all materials showed some damage two weeks after the application. However, none of the damage was statistically significant between the treatments. All of the herbicides used in the study reduced dandelion populations in comparison with the control. No particular product appeared to have greater activity on dandelions than any other product. As with dandelions, all the treatments reduced clover populations significantly. Preen'n Green Lawns provided the best clover control on June 11, 4 weeks after application By July 9, both Preen'n Green Lawns and S-10218 exhibited the best numerical control of clover but there were no statistically significant differences among herbicide treatments. There was not a large differences in turf quality among the treated plots at any time during the study.
Table 1. 2002 Postemergence broadleaf control trial II treatments.
| Material | Total Active Ingredients | Active Ingredients | |
|---|---|---|---|
| 1 | Untreated control | NA | NA |
| 2 | Scotts Turf Builder with Plus 2 Weed Control S-10219 | 1.81% | 2,4-D (1.21%) MCPP-p (0.6%) |
| 3 | S-10218 | 1.89% | 2,4-D (1.21%) MCPP-p (0.6%) Dicamba (0.08%) |
| 4 | Vigoro Weed & Feed | 0.85% | 2,4-D (1.21%) MCPP (0.27%) Dicamba (0.03%) |
| 5 | Sta-green 200 + Weed & Feed | 0.98% | 2,4-D (0.64%) MCPP (0.31%) Dicamba (0.03%) |
| 6 | Sam's Choice Weed & Feed | 1.14% | 2,4-D (0.56%) MCPP (0.29%) 2,4-DP (0.29%) |
| 7 | Preen'n Green Lawns | 1.93% | Benefin (0.82%) Trifluralin (0.43%) Triclopyr (0.5%) Clopyralid (0.18%) |
| 8 | Lesco Weed & Feed | 1.14% | 2,4-D (0.56%) MCPP (0.29%) 2,4-DP (0.29%) |
Table 2. Quality ratings and broadleaf cover in the 2002 postemergence broadleaf control trial II.
| Rate | Weed Phytotoxicity | % Dandelion Cover | % Clover Cover | Turf Quality | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Material | lb a.i./A | 5/28 | 6/11 | 7/09 | 6/11 | 7/09 | 5/28 | 6/11 | 7/09 | |
| 1 | Untreated control | NA | 0 | 38 | 19 | 38 | 21 | 4 | 4 | 5 |
| 2 | Scotts Turf Builder with Plus 2 Weed Control S-10219 | 2.25 | 12 | 8 | 2 | 25 | 6 | 6 | 6 | 6 |
| 3 | S-10218 | 2.25 | 12 | 8 | 3 | 13 | 1 | 6 | 5 | 6 |
| 4 | Vigoro Weed & Feed | 1.18 | 13 | 12 | 3 | 17 | 7 | 6 | 6 | 6 |
| 5 | Sta-green 200+ Weed & Feed | 1.37 | 12 | 17 | 7 | 23 | 4 | 6 | 7 | 6 |
| 6 | Sam's Choice Weed & Feed | 1.79 | 7 | 17 | 5 | 37 | 6 | 6 | 7 | 6 |
| 7 | Preen'n Green Lawns | 3.03 | 8 | 8 | 2 | 4 | 1 | 6 | 6 | 6 |
| 8 | Lesco Weed & Feed | 1.99 | 10 | 13 | 3 | 25 | 8 | 5 | 6 | 6 |
| LSD 0.05 | NS | 9 | 9 | 17 | 7.2 | NS | 1.2 | NS | ||
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ISU Turfgrass:2003 Turfgrass Report | College of Agriculture |
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