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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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.

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

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.

 

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

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Oregon State University has recently released the 31st annual Seed Production Research Report in both hard copy and an online version.  This publication has long been a forum for reports from a variety of seed production researchers, not only from OSU but also from affiliated institutions and agencies.  For much of the Report’s existence, the publication has been edited and produced by Bill Young – now retired professor and extension agronomist in seed production.  This year’s installment was edited by OSU Extension staff members Andrew Hulting, Nicole Anderson, Darren Walenta, and Michael Flowers.

The report is home to articles on a wide range of topics concerning the production of seed from species found in Oregon.  Topics in this year’s edition include weed, insect and disease management; plant growth regulators; irrigation management; and seed testing.  Here’s a link to the online version of the Seed Production Research Report:

2012 Seed Production Research Report

Articles at the linked site can be accessed by clicking on the title of the article.