Category Archives: Grass Seed Crops

Spring-Applied Nitrogen and Trinexapac-ethyl Effects on Seed Yield in Perennial Ryegrass and Tall Fescue

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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.

Seed acreage trends: grass seed crops and wheat

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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 →

New OSU Perennial Ryegrass Seed Crop Nutrient Management Publication

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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

Trinexapac-ethyl PGR increases seed yield in perennial ryegrass across diverse lodging environments

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Here’s  a new article from our research group on trinexapac-ethyl plant growth regulator (PGR) effects in perennial ryegrass seed crops that will be published in Field Crops Research.  This PGR is marketed as Palisade, Moddus, and several generic products.  The trials were conducted from 1998 to 2012 at OSU’s Hyslop Farm.

Figure 1. Lodging in ryegrass.
Figure 1. Lodging in ryegrass.

The study reports several important findings:

  • Application of trinexapac-ethyl PGR reduced stem length and controlled lodging in perennial ryegrass across nine diverse lodging environments in the Willamette Valley of Oregon.
  • Trinexapac-ethyl PGR consistently increased seed yield and harvest index in perennial ryegrass regardless of the severity of lodging.
  • Timing trinexapac-ethyl applications between BBCH stages 32 and 51 produced the best seed yield results.
  • Seed yield increases resulting from trinexapac-ethyl application were attributable to a greater number of seeds spikelet-1 (seed number) and improvements in seed set.

 

Click on the citation below to go to the article:

Chastain, T.G., W.C. Young III, T.B. Silberstein, and C.J. Garbacik.  2014.  Performance of trinexapac-ethyl on seed yield of Lolium perenne in diverse lodging environments.  Field Crops Research 157:65-70.

 

Tillers, Rhizomes, and Stolons

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Thomas G. Chastain

Tillers, rhizomes, and stolons are three types of branches produced by grass plants.  All are stems that branch at some point from the crop’s mainstem or from other stems.

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Figure 1. Kentucky bluegrass plant (T.G. Chastain photo).

The tiller is an above-ground branch on a grass plant.  Tillers are an important component of the crop’s shoot system and through carbon capture and partitioning, contribute to seed yield.  As a tiller grows and develops, additional tillers can form in the leaf axils of that tiller.  All grasses produce tillers. Continue reading →

Pollination and Seed Yield in Grass Seed Crops

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Thomas G. Chastain

Grass seed crops are biologically inefficient in the production of seed.  Many flowers are produced by these grasses yet relatively few of the flowers become seed, thus the potential seed yield may be many times greater than the actual seed yield harvested.  Losses due to inadequate pollination and fertilization, abortion during seed development, and seed shattering all contribute to the relative low numbers of seed that are harvested compared to the crop’s yield potential.

Ryegrass floret

Continue reading →