Thomas G. Chastain

In order to maximize harvest efficiency and seed yield, using the appropriate timing for harvest is essential. Seed moisture content is the most reliable indicator of seed maturity and harvest timing in grass seed crops.

Since pollination and seed maturation are not uniform processes in grass seed crops, a range of seed maturity can be found in a single field. Harvesting within the correct range of seed moisture contents will maximize seed yield and minimize losses of seed during harvest. Seed moisture content is also an important factor in the storage of harvested seed. High seed moisture content reduces longevity of seed in storage and reduces seed quality. Continue reading

That’s the word from Dr. Anthony Montanaro at Oregon Health & Science University in a story published in the Oregonian:

It’s a miserable time for allergy sufferers in Oregon

There’s no question that the flowering of grasses began earlier this spring season in the Willamette Valley as a result of warm weather conditions and that has led to earlier shedding of pollen in the area’s grass seed fields.  However, there is no evidence at this time to indicate that grass pollen and associated problems for allergy sufferers will be headed to a later ending as the article suggests.  In fact, the dryness of the season and warm temperatures strongly support the notion that the grass pollen season will conclude sooner rather than later this year as the crops are already starting to be harvested now.

The present evidence based on the flowering progress of grass seed crops and conditions in the seed fields suggests an early end to the pollen season, not a later end.

Strong creeping red fescue in flower (T.G. Chastain photo)
Strong creeping red fescue in flower (T.G. Chastain photo)


OSU is presenting two seed production field days in May where the public can visit research farms and learn more about research activities. The field days provide a convenient choice for those located in either the western or eastern parts of the state.

May 19 – Grass Seed Field Day – Various topics focused on grass seed production practices and pests including ergot, powdery mildew and weed control, climate change, and more. Starts at 8:30 AM and ends at noon.

Located at OSU’s Hermiston Agricultural Research and Extension Center, 2121 S. First Street, Hermiston, OR 97838. Phone (541) 567-6337.

May 27 – Hyslop Farm Field Day – Plant growth regulators, nutrient and irrigation management in clover seed crops, weed management in grass seed crops, biological control agents for clover root borer, canola, wheat, barley, and more. Starts at 8:15 AM and ends with lunch provided by the OSU Crops Club.

Located at Hyslop Crop Science Field Research Laboratory just off Highway 20 between Corvallis and Albany at 3455 NE Granger Corvallis, OR 97330. Phone (541) 737-6067. Hyslop Farm location


Here’s a video of a presentation that I made at the Pasture Seed Conference in Tasmania:

Presentation Video

The presentation concentrated on some of the advances that have been made in seed production of cool-season grass seed crops.

The slides from the presentation can be accessed here:

Advances in Pasture Seed Production


Here’s a new article from our seed production research and extension team on the rate and timing of trinexapac-ethyl plant growth regulator (PGR) and its effects on seed yield and yield components in tall fescue (Schedonorus arundinaceus (Shreb.) Dumort.) seed crops.  The field trials were conducted in the Willamette Valley over a 6-year period at Hyslop Farm.

This article will appear in an upcoming issue of Field Crops Research and is a part of our series on PGR tools for use in grass and legume seed production.  The product is marketed around the world as Palisade, Moddus, and several generic products for lodging control in grass seed crops and legume seed crops.

Key findings of the article:


  • Trinexapac-ethyl reduced stem length and controlled lodging in tall fescue across six diverse lodging environments.
  • Trinexapac-ethyl consistently increased seed yield in tall fescue, but rate of application had no effect on yield.
  • Timing of trinexapac-ethyl applications had no effect on seed yield.
  • Seed yield increases resulting from trinexapac-ethyl were attributable to greater seed number and harvest index.


The article can be found at the link below:

Chastain, T.G., W.C. Young III, C.J. Garbacik, and T.B. Silberstein. 2015. Trinexapac-ethyl rate and application timing effects on seed yield and yield components in tall fescue. Field Crops Research 173:8-13.



Thomas G. Chastain

The Tasmanian Pasture Seed Conference was held in November in Launceston, Tasmania. The conference was hosted by the Tasmanian Institute of Agriculture, the University of Tasmania, private seed companies and agricultural suppliers and banking interests in Australia.

Several local and international speakers made presentations at the conference and it was attended not only by residents of Tasmania but also by seed producers and company representatives from mainland Australia. Major international seed companies and suppliers were present as well as their local counterparts. The conference began with one day of presentations and discussions regarding the state of the Tasmanian herbage seed industry in comparison with international seed production regions as well as a look at the current state of knowledge in herbage seed production. That was followed up a day later by a well-organized tour of farm fields and production facilities.

Monthly rainfall and temperatures for Oregon's Willamette Valley and Launceston, Tasmania (Graphic by T.G. Chastain).  Click to enlarge.
Monthly rainfall and temperatures for Oregon’s Willamette Valley and Launceston, Tasmania (Graphic by T.G. Chastain). Click to enlarge.

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