1998 Iowa Turfgrass Research Report
1997 Postemergence Ground Ivy Control Study
Barbara R. Bingaman, Nick E. Christians, and Michael B. Faust
The purpose of this study was to evaluate herbicide formulations for their efficacy on ground ivy in turfgrass. The study was conducted on the Iowa State University campus in 'common' Kentucky bluegrass heavily infested with ground ivy. The soil in this area was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with 5.3% organic matter, a pH of 7.5, 12 ppm P, and 165 ppm K.
The study was designed as a randomized complete block. Individual plot size was 5 x 5 ft with three replications. There were five treatments plus an untreated control (Table 1). Experimental formulations EH1312 and EH1342 were applied at two different rates. EH1312 was applied at 1.0 and 1.2 fl oz product/1000 ft2 and EH1342 at 0.8 and 1.0 fl oz/1000 ft2. Trimec Classic was applied at 1.5 fl oz/1000 ft2.
Applications were made postemergently on June 5 after the ground ivy was well established. The materials were diluted in 189 ml water and applied at 30 psi using a CO2 backpack sprayer equipped with #8006 nozzles. This rate translates to 2 gal/1000 ft2.
Damage to ground ivy plants was evaluated using a 9 to 1 scale: 9 = no damage, 7 = slight curling and discoloration, 5 = moderate curling and discoloration, 3 = severe discoloration & curling, 1 = all plants dead. Ground ivy control was assessed using a 9 to 1 scale: 9 = healthy plants, 3 = most plants dead, 1 = all ground ivy plants dead.
Data were analyzed with the Statistical Analysis System (SAS, version 6.10) and the Analysis of Variance (ANOVA) procedure. Means were compared with Fisher's Least Significant Difference (LSD) test.
There was no bluegrass phytotoxicity. Ground ivy damage data were taken on June 10 and June 19 (Table 1). On June 10, all herbicide treated ground ivy had some damage. On June 19, the most severe damage was on ground ivy treated with EH1312 at 1.0 fl oz product/1000 ft2 and EH1342 at 0.8 fl oz product/1000 ft2. Mean damage for these two dates showed that all herbicides produced significant damage when compared with the untreated control.
By June 26, there was high ground ivy mortality in all treated bluegrass. Most of the treated ground ivy plants were dead by July 2. All treated ground ivy plants treated with EH1342 at 0.8 fl oz product/1000 ft2 were dead on July 2. The plot was monitored through September and there was no regrowth of ground ivy in the treated turf.
Table 1. Ground ivy control with various herbicides used in the 1997 Postemergence Ground Ivy Control Study.
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Untreated control |
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Trimec Classic |
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EH1312 |
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EH1312 |
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EH1342 |
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EH1342 |
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LSD0.05 |
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1Degree of damage was evaluated using a 9 to 1 scale: 9 = no damage, 7 = slight curling and discoloration, 5 = moderate curling and discoloration, 3 = severe discoloration & curling, 1 = all plants dead.
2Ground ivy control was assessed using a 9 to 1 scale: 9 = healthy plants, 3 = most plants dead, 1 = all plants dead.
Materials were applied on June 5, 1997
NS = means are not significantly
different at the 0.05 level.
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ISU Horticulture:Publications:1998 Turfgrass Report | College of Agriculture |