Nick E. Christians and Luke Dant
The purpose of this study was to compare the speed of activity and length of control of Monsanto's QuikPRO and Roundup ProDry. This study was conducted at the Iowa State University Turfgrass Research Facility on 'Ram I' Kentucky bluegrass. The soil on the area is a Nicollett (fine-loamy, mixed, mesic Aquic Hapludoll) with 4.1 % organic matter, 11 ppm P, 96 ppm K, and a pH of 6.75.
The trial design was a randomized complete block. The plots were 5 ft x 5 ft and each treatment was replicated three times. Each treatment was diluted to a total spray volume of 3 gal per 1000 sq ft and applied using a carbon dioxide backpack sprayer with #8002 flat fan TeeJet nozzles at 30-40 psi. All treatments were applied on July 17.
Turfgrass phytotoxicity was monitored at approximately 1, 2, 3, 7, 28, 56, and 84 days after application on a scale ranging from 9-1, with 9 being no damage and 1 being complete death of the turf.
Data were analyzed using Statistical Analysis System (SAS) and the Analysis of Variance procedure. Treatment effects were tested using Least Significant Difference (LSD) test.
The QuikPRO treated plots were showing significant damage on the first day after treatment (Table 1). The Roundup ProDry treated plots did not show damage until the 5th day after treatment. QuikPRO had completely killed the grass by day 7, whereas, it was 14 days following treatment before Roundup ProDry completely killed the turf. None of the treated grass showed any sign of recovery at the end of the season.
Table 1. Comparison of the time required to kill Kentucky bluegrass of QuikPro and Roundup ProDry. (9=no damage and 1=dead turf)
| Rate | Turfgrass Phytotoxicity | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Material | lb ai/A | 7/18 | 7/19 | 7/20 | 7/22 | 7/24 | 7/31 | 8/7 | 8/14 | 8/28 | 9/13 | 10/14 | |
| 1 | Untreated Control | NA | 9 | 9 | 9 | 9 | 9 | 8 | 8 | 9 | 9 | 9 | 9 |
| 2 | QuikPro (66.6% glyphosate) | 6 | 6 | 4 | 4 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| 3 | Roundup ProDry (64.9% glyphosate) | 6 | 9 | 9 | 9 | 7 | 4 | 1 | 1 | 1 | 1 | 1 | 1 |
| LSD 0.05 | 0.8 | 0.8 | 0.8 | 0.8 | 1.2 | 0.8 | 0.8 | 1.0 | 1.0 | 1.0 | 1.0 | ||
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ISU Turfgrass:2003 Turfgrass Report | College of Agriculture |
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