Plant Growth Regulators « Seed Production

Thomas G. Chastain

Here’s a new article from our seed production research and extension team on irrigation and trinexapac-ethyl PGR effects on seed yield and yield components in red clover seed crops. Field trials were conducted in the Willamette Valley over a 3-year period at OSU’s Hyslop Farm. Trinexapac-ethyl is marketed around the world as Palisade, Moddus, and several generic products for lodging control and seed yield enhancement in cool-season grass seed crops and legume seed crops.

Floret bleaching in red clover, a common effect of TE PGR application (TG Chastain photo) — Floret bleaching in red clover, a common effect of trinexapac-ethyl PGR application (TG Chastain photo)

This article appears in the current issue of Agronomy Journal and can be found at the link below:

Anderson, N.P., T.G. Chastain, and C.J. Garbacik. 2016. Irrigation and trinexapac-ethyl effects on seed yield in first- and second-year red clover stands. Agron. J. 108:1116-1123.

Key findings of the article:

Irrigation strategically-timed to coincide with peak flowering consistently increased seed yield in red clover regardless of stand age.
Trinexapac-ethyl PGR increased seed yield in second-year red clover stands but not in first-year stands.
Irrigation and trinexapac-ethyl independently increase the yield of red clover seed crops but there were no interactions between the two.

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 trinexapac-ethyl plant growth regulator (PGR) and its effects on seed yield and yield components in red clover (Trifolium pratense L.) seed crops. The field trials were conducted in the Canterbury region of New Zealand and in seed fields in the Willamette Valley.

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

Key findings of the article:

Trinexapac-ethyl was responsible for seed yield increases in red clover ranging from 9 to 15% in New Zealand and Oregon’s Willamette Valley.
One contributing factor for the increased seed yield with trinexapac-ethyl was that the PGR increased the number of heads formed in the red clover crop. Moreover, the PGR reduced the height of the crop canopy and increased penetration of light into the canopy, possibly leading to the increased head production.
Timing of trinexapac-ethyl applications to coincide with early stem elongation gave the best seed yields although split applications at stem elongation and bud emergence produced yield increases in Oregon.
Seed weight was generally inversely related to yield; trinexapac-ethyl treatments that produced the highest yield also had the lowest seed weight.

The article can be found at the link below:

Anderson, N.P., D.P. Monks, T.G. Chastain, M.P. Rolston, C.J. Garbacik, Chun-hui Ma, and C.W. Bell. 2015. Trinexapac-ethyl effects on red clover seed crops in diverse production environments. Agron. J. 107:951-956.

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.

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)

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.

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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Seed Production

Tag Archives: Plant Growth Regulators

Irrigation and PGR use in red clover seed crops

Advances in Pasture Seed Production

Trinexapac-ethyl effects on red clover seed production

Trinexapac-ethyl rate and timing effects on tall fescue seed production

PGR and burning effects on expression of seed yield components in strong creeping red fescue

Plant growth regulators – lodging control agents for grass seed crops

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