Thomas G. Chastain

In order to maximize harvest efficiency and seed yield, using the appropriate timing for harvest is essential. Seed moisture content is 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

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)

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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

Thomas G. Chastain

Research conducted at Hyslop Farm has shown that spring irrigation in tall fescue and perennial ryegrass can increase seed yield.  The soil at Hyslop Farm is a medium textured soil (Woodburn silt loam) that is typical of many places in the valley where tall fescue and perennial ryegrass seed crops are grown.  This soil is deep and has good water holding capacity.

Tall fescue seed yield responses to spring irrigation varied among the cultivars tested.  Increased number of seed in tall fescue was most responsible for the seed yield improvement observed with spring irrigation.   Strategic timing of spring irrigation to support seed filling was more important for increasing seed yield than season-long irrigation.  Spring irrigation increased seed yield up to 39%.  First years stands of stands of tall fescue averaged 28% increase in seed yield with spring irrigation while second year stands averaged 11% increased yield. Continue reading

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.