Thomas G. Chastain

Annual ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot] seed crops have been produced on some Oregon farms continuously for decades without rotation of crops or farming practices.  The long-term influences of this continuous cropping of annual ryegrass have not been examined nor have any long-term practices been evaluated in annual ryegrass seed production.

Annual ryegrass seed field in Oregon (TG Chastain photo)

Long-term annual ryegrass cropping systems trials were initiated in the 2005-06 crop year in a project led by former OSU Extension Agent, Mark Mellbye.  His vision was for a 9-year project to study the long-term effects of several cropping practices on annual ryegrass seed production.

While there are several long-term cropping systems practices studies in field crops such as wheat at a variety of locations around the world, no long-term studies in grass seed crops and annual ryegrass in particular, have ever been conducted.  The following six cropping systems practices treatments were employed in the study:

  1. Continuous conventional tillage and planting system
  2. Continuous no-till planting system
  3. No-till/conventional tillage rotation (alternate year tillage)
  4. Volunteer/conventional tillage rotation (alternate year tillage)
  5. Burn and no-till/conventional tillage rotation (alternate year tillage)
  6. Volunteer/no-till/conventional tillage rotation (tillage every 3rd year)

The following were the primary findings of the study:

  • Annual ryegrass seed yield varied with tillage and establishment system, and environment.
  • No-till produced the lowest seed yields.
  • Environment x system interaction effects governed seed production characteristics.
  • Increased tillage frequency and residue removal are required to sustain long-term seed yields.
  • Yield differences among systems were attributable to seed number.

This article was published in Field Crops Research and can be found at the link below:

Chastain, T.G., C.J. Garbacik, and W.C. Young III. 2017. Tillage and establishment system effects on annual ryegrass seed crops. Field Crops Res. 209:144-150.



Our research and extension team has published a Pacific Northwest Extension bulletin on camelina stand establishment.  The work was done across multiple environments in the Pacific Northwest ranging from arid eastern Washington to the wet Willamette Valley.  The effects of planting date and method were examined in relationship to establishment of camelina stands and seed yield.

The article can be accessed at the link below:

Schillinger, W.F., D.J. Wysocki, T.G. Chastain, S.O. Guy, and R.S. Karow.  2014.  Camelina: effects of planting date and method on stand establishment and seed yield.  Pacific Northwest Extension Publication, PNW 661.

A new publicPicture1ation on nutrient management in perennial ryegrass seed crops has just been released by OSU’s grass seed production research and extension team.  The publication (EM 9086) is a product of many years of  field work in grass seed crops by the members of the research and extension team.  The nutrient management guide covers the impacts of application of nutrients on seed yield, seed yield components, crop growth and development, plant growth regulator use, pests, and others.  Extensive use of tables, figures, and appendices supplement this comprehensive work on perennial ryegrass nutrient management.

The publication can be accessed at the link below:

Perennial Ryegrass Grown for Seed (Western Oregon) EM 9086