1998 Iowa Turfgrass Research Report
Creeping Bentgrass Fertility Trial Results - 1997
James R. Dickson and Nick E. Christians
Introduction
Two liquid products and one granular product from the Ringer Corp. were tested against Plant Marvel (20-5-30) and a control of urea. All treatments were applied at the rate of 4 lbs N per 1000 sq. ft. per year. The applications were made at two-week intervals over a period of 20 weeks (ten applications) between May 26 and September 29, 1997. They were applied on Penncross creeping bentgrass growing on a sand-based golf green which was constructed to USGA specifications.
This report summarizes information on turf visual quality, shoot clipping yield, and root growth. The clipping yield data were collected once per month beginning July 29th. These clippings were collected one week after treatment application. Visual quality data were collected, beginning July 7th, during the weeks when no treatments were applied. Roots samples were collected September 17, 1997.
Methods and Materials
The treatments in this trial were applied in a randomized complete block design with 3 replications on 5 x 5 ft plots (Figure 1). All treatments were diluted in deionized water to yield a volume of 560 ml. They were then applied to the plots through a CO2 pressurized 3-nozzle wand with TeeJet XR 8005 nozzles.
Visual quality ratings were based on turf color and density. A 9 to 1 scale was employed with 9 being the best possible quality and 1 representing dead turf.
A non-motorized, Ransom greens mower was used for obtaining clippings. The clippings were placed in paper sacks and dried at 70š C for at least 48-hours. Their weights were then measured to the nearest 0.01-g.
Six 2 x 15 cm cores were collected from each plot for root weight measurements. These cores were divided into three 5 cm increments and all six cores within a 5 cm depth interval were combined. The roots were washed by hand and collected on a No. 40 U.S.A. standard sieve. They were then dried at 70š C for at least 48 hours. The oven-dry weights were measured to the nearest 0.0001-g prior to ashing at 500š C for at least 24 hours. The ash weights were then measured to the nearest 0.0001-g, and subtracted from the oven-dry weight.
A statistical analysis of the treatment results for visual quality, the shoot weights (by event and cumulative) and root weights (by treatment and depth) was conducted using the Statistical Analysis System (SAS) to determine treatment effects.
Results and Discussion
Significant treatment differences in clipping weight (Table 1) were observed in September data only. There were no treatment differences for the annual average clipping weights.
There were no treatment differences observed in the data from the root samples (Table 2).
There were no apparent visual quality differences between the treatments until late-September (Table 3). At that date, it became apparent that the grass receiving the Ringer "C2" treatment and the urea (control) treatment were producing a darker green color.
Table 1. 1997 mean clipping yields (g)
Treatment
Ringer[C-1]
31.1
32.4
5.22
9.9
19.6
C-1 +Ringer (5-2-10)
37.3
40.7
6.6
14.5
24.8
Ringer[C-2]
35.3
33.6
5.1
11.6
21.4
Plant Marvel (20-5-30)
35.4
32.6
6.5
13.0
21.9
Control (urea)
32.6
33.0
5.0
12.2
20.7
LSD0.05
2.50
Table 2. 1997 mean root yields (g) at three depth intervals
Treatment
Ringer[C-1]
1.112
0.481
0.179
0.591
C-1 +Ringer (5-2-10)
1.125
0.411
0.230
0.588
Ringer[C-2]
1.240
0.401
0.240
0.627
Plant Marvel (20-5-30)
1.152
0.448
0.370
0.657
Control (urea)
1.089
0.218
0.193
0.592
LSD0.05
Table 3. 1997 mean visual quality ratings
|
|
|
|
|||||||
|
Treatment |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Ringer[C-1] |
5.7 |
6.7 |
6.7 |
6.7 |
6.7 |
7.0 |
6.3 |
6.0 |
6.45 |
|
C-1 +Ringer (5-2-10) |
6.0 |
7.0 |
7.0 |
7.3 |
7.0 |
7.3 |
7.0 |
7.0 |
6.96 |
|
Ringer[C-2] |
6.0 |
7.0 |
7.0 |
7.3 |
7.0 |
7.7 |
7.7 |
7.7 |
7.17 |
|
Plant Marvel (20-5-30) |
6.0 |
7.0 |
7.0 |
7.0 |
7.0 |
7.0 |
7.3 |
7.0 |
6.92 |
|
Control (urea) |
6.0 |
7.0 |
7.0 |
7.7 |
7.0 |
7.7 |
8.0 |
8.0 |
7.29 |
|
|
|
|
|
|
|
|
|
|
|
|
LSD0.05 |
|
|
|
|
|
|
0.69 |
0.49 |
0.31 |
 |
ISU Horticulture:Publications:1998 Turfgrass Report | College of Agriculture |