Thomas G. Chastain

Why is lodging important in grass seed crops?

Under certain conditions, the tiller cannot support the weight of the developing inflorescence and seed. The tiller lodges or falls to the ground, especially when there are high levels of nitrogen fertilizer and soil moisture present (Fig. 1). Both conditions are common in Oregon’s commercial grass seed production fields in the spring.

Figure 1. Lodging in ryegrass. (T.G Chastain photo)

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Bill Young, OSU professor emeritus and extension agronomist in seed production, has recently updated Oregon’s grass and forage legume seed crop production statistics for the 2013 crop year. This report provides a wealth of useful information about quantity of seed produced, crop yields, and economic value of these seed crops in Oregon.

Here is a summary of the findings from Dr. Young:

In brief, the combined value for all grass and legume seed crops in the 2012-13 crop year ($461,693,000) increased 13.6% over the value of production in 2011-12. Oregon growers harvested 415,916 acres of grass seed crops in 2013, an increase of just 7,916 acres (+1.9%) over last year. However, the estimated value of all grass seed species increased by 12.7% due to the improved prices received by grower.  Legume seed crop acreage declined slightly (-1.6%) from the 2011-12 crop year, but the $44,067,000 value marked a new high for this industry.  Further details are examined in Dr. Young’s “Narrative Discussion” and its accompanying tables.

Here is a link to the report on OSU’s Seed Crops page:

2013 Grass and Legume Seed Crop Estimates

You can follow the links on the Seed Crops page to find information about this past year’s seed crops and comparisons to previous crop years. Historical reports are also archived at this page.

Here’s a new article from our research group on the impacts of spring applied nitrogen and trinexapac-ethyl plant growth regulator (PGR) effects in perennial ryegrass and tall fescue seed crops.  This article is in the current issue of Agronomy Journal and is a part of our series on PGR in grass and legume seed production.  The product is marketed as Palisade, Moddus, and several generic products for lodging control in grass seed crops and legume seed crops.

Effect of spring-applied N (160 lbs/acre - left) and no spring-applied N (right) on lodging and canopy structure in perennial ryegrass seed crops (T.G. Chastain photo).
Effect of spring-applied N (160 lbs/acre – left) and no spring-applied N (right) on lodging and canopy structure in perennial ryegrass seed crops (T.G. Chastain photo).

Key findings of the article:

  • Identifies an interaction of spring-applied N and PGR application on seed yield and other seed production characteristics in perennial ryegrass and tall fescue.
  • Is the first peer-reviewed publication to document the effect of trinexapac-ethyl PGR on increasing seed yield in tall fescue.
  • Seed yield was only increased in perennial ryegrass and tall fescue by the PGR when recommended rates of applied rates of spring N were made.
  • Although seed weight was increased by spring N, most of the effect of the combination of spring-applied N and PGR on increasing seed yield was attributable to increases in seed number.

The article can be found at the link below:

Chastain, T.G., C.J. Garbacik, and W.C. Young III.  2014.  Spring-applied nitrogen and trinexapac-ethyl effects on seed yield in perennial ryegrass and tall fescue.  Agron J. 106:628-633.

Thomas G. Chastain

Grass seed crop acreages in Oregon’s Willamette Valley have varied over time.  One interesting aspect of the rise and fall of grass seed crop acreages in the region is their relationship with wheat acreages in the Willamette Valley.  A rise in grass seed crop acreage is mirrored by a simultaneous fall in wheat acreage and vice versa, and these trends are evident in the graphic below.

Grass seed and wheat trends Continue reading

Thomas G. Chastain

The media is reporting that 2013 was a very dry year unlike any in the recent past.  The graphic below shows the long-term annual precipitation for Corvallis since the late 1880s.  Also on the graph is the long-term average (dashed line), a 5-year running mean, and the individual orange triangle symbols show the yearly annual precipitation.  The precipitation for 2013 is indicated by the round black symbol.

Annual precipitation at Corvallis Oregon.
Annual precipitation at Corvallis Oregon.

The graphic shows that while 2013 was very dry, there have been other years that have also been similarly dry or drier than the present.  Examination of the trends in the 5-year running mean show that there are cyclical wet and dry periods that are evident in the precipitation record over time with the driest period in the 1930s.  The region is currently in a dry period that began in the early 2000s.

What does this mean for the region’s seed crops?  It is too early to know at this point but we do know this, seed yield is rarely affected by annual precipitation.  Seasonal precipitation such as in spring is much more important for high seed yields in crops such as grass seed crops than annual precipitation.  Even though the year might be dry overall, yields still can be good if spring rainfall is near normal.

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