CFAES Give Today
Agronomic Crops Network

Ohio State University Extension


Winterkill of Italian Ryegrass Stands

(Editor's note: John McCormick was also an author on this article) Last week we observed the worst winter injury in Italian and annual ryegrass stands since 2004 when we first began testing this species on an annual basis. We have received several reports of cover crop stands of annual ryegrass that did not survive the winter at all. Do continue to monitor those stands for recovery, as a burndown herbicide may still be needed if there are some surviving tillers.

We planted 32 different varieties of annual and Italian ryegrass on 16 September 2013 at the Western Agricultural Research Center near South Charleston. Of the 32 varieties, only four showed somewhat acceptable spring vigor and stand density, and even those sustained some damage along the west side of the plots (see accompanying images).

The four varieties that had significantly lower winter injury ratings than the rest were Winterhawk (marketed by Oregon seeds), Marshall (marketed by Wax Seed Co.), an experimental variety not on the market, and Fria (marketed by Allied Seed Co). Five to six other varieties had significant damage but may recover some, while 21 varieties appeared to be dead or mostly dead at this point in time. Marshall, which has been our check variety, has greater cold tolerance than most varieties on the market.

All 32 varieties had 100% ground cover going into the winter and we harvested them for forage yield last November (see results at

On Monday the 21stĀ of April, the only real change in the appearance of the plots was that winter annual weeds are becoming more obvious. We observed no substantial differences in recovery of the varieties from 10 days ago when the pictures were taken. We will report results from this trial in this newsletter at the conclusion of the trial and in the 2014 Forage Performance Trials Report.

Crop Observation and Recommendation Network

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.