ITALIAN RYEGRASS CONTROL IN WINTER WHEAT
Dallas E. Peterson, Scott Gordon, Gary Kilgore, and Ken Kelley
Introduction and Procedures
An experiment was conducted near Dearing in southeast Kansas to evaluate fall and spring
postemergence herbicide treatments for Italian ryegrass (Figures 1 and 2) control in “2174” hard red winter
wheat seeded on October 27, 2003. Fall postemergence (FP) treatments were applied to 2-leaf wheat, and
1- to 2 leaf Italian ryegrass on November 21 with 65 F, 42% relative humidity, and clear skies. Spring
postemergence (SP) treatments were applied to tillered wheat and Italian ryegrass on March 19 with 74 F,
56% relative humidity, and mostly cloudy skies. Treatments were applied with a CO 2 back-pack sprayer
delivering 15 gpa at 25 psi through TT110015 Turbo Tee spray tips to the center 6.3 ft of 10- by 25-ft plots.
The experiment was a randomized complete block design with three replications. Wheat injury and ryegrass
control were evaluated June 1. Wheat was harvested on June 18.
Results and Discussion
Fall and spring treatments with Osprey or Olympus plus Osprey, and fall applications of Finesse or
Hoelon gave near complete control of Italian ryegrass (Figures 3-6). Ryegrass control was better with fall
than spring treatments of Finesse, Hoelon, Achieve, Maverick, and Olympus. Several treatments caused
some wheat stunting, which diminished over time. Wheat yields and foreign matter content generally
corresponded to Italian ryegrass control. (Dept. of Agronomy, Kansas State University, Manhattan).
Table. Italian ryegrass control in winter wheat (Peterson, Gordon, Kilgore, and Kelley).
Application
Italian
Wheat
Treatmenta
Rateb
Timec
ryegrass Injury
Yield
(Product/acre)
(% control) (%)
(Bu/Ac)
FM
(%)
Cost
($/Ac)
Finesse +NIS
Finesse +NIS
Hoelon + COC
Hoelon + COC
Hoelon + COC
Maverick + NIS
Maverick + NIS
Olympus + NIS
Olympus + NIS
Osprey + MSO
Osprey + MSO
Olympus + Osprey + NIS
Olympus + Osprey + NIS
Achieve + NIS + AMS
Achieve + NIS + AMS
50
37
47
45
48
46
41
42
43
47
44
50
48
53
46
0.9
2.6
0.8
0.6
0.7
1.0
2.6
1.4
2.1
0.7
0.7
0.5
0.6
0.7
1.7
6.25
6.25
11.50
11.50
17.00
10.00
10.00
10.00
10.00
14.50
14.50
13.00
13.00
13.75
13.75
32
5.9
No Treatment
0.4 oz + 0.25%
0.4 oz + 0.25%
1.33 pt + 1 pt
1.33 pt + 1 pt
2 pt + 1 pt
2/3 oz + 0.5%
2/3 oz + 0.5%
0.9 oz + 0.25%
0.9 oz + 0.25%
4.75 oz + 1.5 pt
4.75 oz + 1.5 pt
0.3oz+3.2oz+0.5%
0.3oz+3.2oz+0.5%
7 oz+0.5%+1%
7 oz+0.5%+1%
FP
SP
FP
SP
SP
FP
SP
FP
SP
FP
SP
FP
SP
FP
SP
98
33
100
89
94
82
57
68
58
97
100
97
100
94
65
6
0
3
3
3
0
0
2
0
2
6
0
4
0
0
LSD (5%)
8
3
8
1.2
a
NIS = Activate Plus nonionic surfactant from Agriliance; COC = Crop Oil Plus from Agriliance;
MSO = Destiny methylated seed oil from Agriliance.
b
% = % v/v.
c
FP = fall postemergence; SP = spring postemergence.
Figure 1. Italian ryegrass in plot area
Figure 2. Italian ryegrass, cheat, and downy brome
Figure 3. Fall applied Finesse
Figure 4. Spring applied Finesse
Figure 5. Fall applied Hoelon
Figure 6. Spring applied Osprey