Skip to main content Accessibility help

Italian Ryegrass (Lolium multiflorum) Accessions Tolerant to Diclofop

  • Charles E. Stanger (a1) and Arnold P. Appleby (a2)


In 1987, two applications of the methyl ester of diclofop failed to effectively control Italian ryegrass in some growers' fields. As a result of these observations, studies were initiated to determine if the surviving ryegrass is more tolerant to diclofop than previously untreated ryegrass. Growth chamber studies on five accessions of ryegrass demonstrated that collections from two growers' fields were highly tolerant of diclofop. Diclofop GR50 (rate required to reduce shoot weight by 50%) values of accessions A and B and commercial ryegrass, when diclofop was applied to seedlings at the two-leaf stage, were 2.9, 3.4, and 0.0056 kg ai/ha, respectively. Diclofop-tolerant biotypes were not more tolerant to postemergence barban or preemergence-incorporated triallate plus postemergence diuron or metribuzin. These herbicides are possible alternative treatments in fields where diclofop is no longer effective.



Hide All
1. Appleby, A. P., Olson, P. D., and Colbert, D. R. 1976. Winter wheat yield reduction from interference by Italian ryegrass. Agron. J. 68:463466.
2. Brewster, B. D., Appleby, A. P., and Spinney, R. L. 1977. Control of Italian ryegrass and wild oats in winter wheat with HOE 23408. Agron. J. 69:911913.
3. Burrill, L. C. and Appleby, A. P. 1978. Influence of Italian ryegrass density on efficacy of diuron herbicide. Agron. J. 70:505506.
4. Cochran, W. G. 1977. Sampling Techniques. 3rd ed. John Wiley and Sons, New York.
5. Heap, J. and Knight, R. 1982. A population of ryegrass tolerant to the herbicide diclofop methyl. J. Aust. Inst. Agric. Sci. 48:156157.
6. Khodayari, K., Frans, R. E., and Collins, F. C. 1983. Diclofop—a selective herbicide for Italian ryegrass (Lolium multiflorum) control in winter wheat (Triticum aestivum). Weed Sci. 31:436438.
7. LeBaron, H. M. and Gressel, J. 1982. Herbicide resistance in plants. John Wiley and Sons, New York. 401 pp.


Italian Ryegrass (Lolium multiflorum) Accessions Tolerant to Diclofop

  • Charles E. Stanger (a1) and Arnold P. Appleby (a2)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed