Thomas G. Chastain

Several scales have been constructed for use in assigning developmental stages to crop plants.   The BBCH (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie) scale is used to ascertain the developmental stages of crops and is based on the Zadoks scale for cereals but has been standardized and extended to many other crops including dicots.

The uniform nature of the BBCH scale has encouraged the wide-spread use of this system by agronomists and by agricultural practitioners alike.  One advantage of the BBCH scale is the simplicity of staging of crop plants because only one scale (with minor modification) is needed for multiple species.

Ten principal stages form the basis for the scale in each crop.  Below is a table showing the adaptation of the scale for grass seed crops.

Stage Description – BBCH scale
0-9 Seed germination/bud development
10-19 Leaf development
20-29 Tiller development
30-39 Stem elongation
40-49 Booting
50-59 Inflorescence emergence/development
60-69 Flowering/pollination
70-79 Seed development
80-89 Seed maturation and harvest
90-99 Senescence

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A new nutrient management guide for tall fescue seed crops has been published by OSU’s seed production research and extension team.  The 42-page publication (EM 9099) is a product of many years of  field work in tall fescue seed crops by the members of the research and extension team.

Tall fescue cover

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 guide to tall fescue seed crop nutrient management.

The publication can be accessed at the link below:

Tall Fescue Grown for Seed: A Nutrient Management Guide for Western Oregon, EM 9099

Thomas G. Chastain

Our work on grass seed crop residue management suggests that the answer to this question depends on the grass crop species.  On-farm trials over 60 site-years and in 6 seed crops species across Oregon were used to compare baling straw with and without flailing of the crop stubble.  In several of our grass seed crops including perennial ryegrass, tall fescue, orchardgrass and Chewings fescue, the differences in seed yield for baling and post-bale flail chopping of a field were negligible and were not statistically significant.  Thus, there was no requirement for flailing of these crops after baling of the straw in order to harvest good seed yields.

Stack of straw bales in grass seed field (T.G. Chastain photo)
Stack of straw bales in grass seed field (T.G. Chastain photo)

Continue reading

Grass seed harvest continues to progress here in the Willamette Valley and thoughts will soon turn to residue management. Fig. 1.  Smoke plume from open-field burning in Oregon's Willamette Valley.

Smoke plume from open-field burning in Oregon’s Willamette Valley in the 1990s.  (T.G. Chastain photo)

 

 

 

I’m reminded each year at this time of the challenges of grass seed crop residue management in the 1990s and the transition from a burning-based system to one that involves management of the straw and stubble by using non-thermal techniques.  This topic was addressed in a 1998 Oregon’s Agricultural Progress article linked below:

Splendor in the Mass

Thomas G. Chastain

Grass seed harvest has begun here in the Willamette Valley.  In order to maximize harvest efficiency and seed yield, using the appropriate timing for harvest is essential.  Seed moisture content has been found to be 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

Here’s a new article from our seed production research and extension team on trinexapac-ethyl plant growth regulator (PGR) and field burning effects on the expression of yield components in strong creeping red fescue (Festuca rubra L. subsp. rubra) seed crops.  The field trials were conducted in the Willamette Valley over a 4-year period at Hyslop Farm.

This article will appear in the next issue of Agronomy Journal and is a part of our series on PGR tools for use 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.

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

Key findings of the article:

  • Fall applications of the PGR had no effect on seed yield components.
  • Culm length was reduced and lodging was lessened by spring applications of PGR in strong creeping red fescue.
  • Spring applications of PGR increased the number of florets produced.
  • A combination of burning and spring PGR applications increased seed number and seed weight, thus contributing to higher seed yields in strong creeping red fescue.

The article can be found at the link below:

Zapiola, M.L., T.G. Chastain, C.J. Garbacik, and W.C. Young III.  2014.  Trinexapac-ethyl and burning effects on seed yield components in strong creeping red fescue.  Agron J. 106:1371-1378.