Author
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Ries, Ronald |
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Submitted to: Journal of Range Management
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/19/1998 Publication Date: N/A Citation: N/A Interpretive Summary: The depth of the grass crown in the soil influences the susceptibility of the crown to environmental and management conditions which can affect grass establishment success and forage and grain yields. A growth chamber experiment was conducted to quantify the effect of planting depth, temperature, and light on the length of oat seedling internodes and the resulting final crown depth. The 1st and 1st leaf internodes increased in length with increased planting depth. The length of the 2nd and 3rd leaf internodes did not develop the same length in relationship to temperature, light, or planting depth. The length of these internodes resulted in the depth and structure of the final oat crown. Since the internodes do not respond the same to environmental conditions, each internode must be identified and observed individually. When all factors resulting in oat crown depth location and structure are considered, one expects the crowns of oat seedling developed under cool temperatures to contain 4 closely located nodes, and crowns developed under warmer temperatures to containing only 3 separated nodes. The most compact crowns developed under reduced light conditions and from shallow planting depths with cool temperatures. These data provide an idea of what crown location and structure can be expected in the field during growing seasons with cool to warm temperatures and low to high light intensities for annual and perennial forage grasses with an oat type seedling morphology when seeded at shallow or deep planting depths. Technical Abstract: The depth of the grass crown nodes in the soil influences the susceptibility of the crown to environmental and management conditions which can affect grass establishment success and forage and grain yields. A growth chamber experiment was conducted to quantify the effect of planting depth (38 and 76 mm), temperature (10 and 25 C), and light (shaded dat 55% full light [500 u moles m-2s-1] and full light [900 u moles m-2s-1] on the elongation of oat seedling internodes and the resulting final crown placement. The mesocotyl and 1st leaf internode increased in length with increased planting depth with no significant interactions. The length of the 2nd leaf internode increased more when developed under 25 C than under 10 C (significant temperature x depth interaction) and elongated more under 55% full light compared to full light (significant light x depth interaction). The 3rd leaf internode length was the same for the 38 and 76 6mm depths when developed at 10 C and under 55% full light. At 10 C-full light and 25 C-55% full light, the deep planting depth resulted in increased 3rd leaf internode length, while, at 25 C-full light, the 3rd leaf internode was longer when developed from 38 mm planting depth (significant temperature x light x depth interaction). The elongation of these internodes resulted in the depth and structure of the final oat crown. Since the internodes do not respond the same to environmental conditions, each internode must be identified and observed individually. These data provide an idea of what crown location and structure can be expected in the field during growing seasons with variable temperature and light conditions for annual and perennial forage grasses with an oat type seedling morphology when seeded at specific planting depths. |
