Fairway Height Preemergence Herbicide Trial 2002

Nick Christians and Luke Dant

The 2002 fairway height preemergence trial was conducted at the Iowa State University Turfgrass Research Facility on an area of 'Quantum Leap' Kentucky bluegrass maintained as a golf course fairway at 0.5 in. mowing height. The area for the trial was limited and the study was conducted with two replications instead of the standard three replications. The herbicides were applied on May 14 with a CO2 backpack sprayer with #8002 flat fan TeeJet nozzles at 30-40 psi and diluted to a total spray volume of 3 gal per 1000 sq. ft. The second application of treatment 1 was made on July 1 using the same procedure as described above. The soil on the area is a Nicollett (fine-loamy, mixed, mesic Aquic Hapludoll) with 3.3 % organic matter, 7 ppm P, 50 ppm K, and a pH of 6.65.

Data were analyzed using Statistical Analysis System (SAS) software and the Analysis of Variance procedure. Treatment effects were tested using Least Significant Difference (LSD) test.

Crabgrass populations were variable on the site. Treatment 1 (low rate of Dimension Ultra) had higher crabgrass populations than that of the control plots. This is most likely due to great variability of crabgrass populations at the site. However, it was clear that the 0.25 lb ai/A rate of Dimension was not sufficient to control crabgrass on this site, whereas the 0.5 rate was effective. The Barricade at 0.5 lbs ai/A was also effective in this test. No damage from the treatments was observed on the Quantum Leap bluegrass at anytime during the study.

Table 1. Fairway height bluegrass preemergence trial 2002.

		Rate	% Crabgrass Cover
	Material	lb a.i./A	7/23	8/19	9/23
1	Dimension Ultra 40 WP2 (Split Applications)	0.25	6	28	20
2	Dimension Ultra 40 WP2	0.5	1	1	0
3	Barricade 65 WG2	0.5	0	1	1
4	Untreated Control	NA	6	14	11
	LSD 0.05		NS	17	NS

ISU Turfgrass:2003 Turfgrass Report

College of Agriculture

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