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Analysis Of The Effects Of Hypogeal And Epigeal Emergence On Seedling Competition In Legumes, Keith E. King

McCabe Thesis Collection

Seedling emergence is either hypogeal or epigeal. In hypogeal emergence the cotyledons remain below the soil surface during seedling development, while in epigeal emergence the cotyledons extend above the soil surface due to elongation of the hypocotyl. Here we examine the effect of seed size, and emergence type, on seedling growth. Six legumes with variation in seed size and either epigeal or hypogeal emergence were grown under dark and light conditions. A competition study was also conducted where a hypogeal and epigeal legume were grown in combination with wheat and ryegrass. Legumes expressing epigeal emergence were cowpea (Vigna unguiculata), mung …

Physiological And Biochemical Aspects Of Agrobacterium-Wheat (Triticum Aestivum L.) Interactions, David L. Parrott Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Agrobacterium tumefaciens and A. rhizogenes are the causal agents of gall or hairy root disease, but normally the bacteria do not cause disease in wheat. However, both bacteria grew without inhibition when exposed to intact or wounded wheat roots or embryos, and they colonized wheat root surfaces to levels similar to dicotyledonous plants. A. tumefaciens and A. rhizogenes induced 23% cell death after a 1-h exposure to wheat embryo cells grown in 7.4 mM O₂, while the extent of cell death at 2.1 mM O₂ was 8%. Contact with A. tumefaciens or A. rhizogenes caused cultured wheat …

Use Of Ground-Based Canopy Reflectance To Determine Radiation Capture, Nitrogen And Water Status, And Final Yield In Wheat, Glen L. Ritchie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ground-based spectral imaging devices offer an important supplement to satellite imagery. Hand-held, ground-based sensors allow rapid, inexpensive measurements that are not affected by the earth’s atmosphere. They also provide a basis for high altitude spectral indices.

We quantified the spectral reflectance characteristics of hard red spring wheat (Triticum aestivum cv. Westbred 936) in research plots subjected to either nitrogen or water stress in a two year study. Both types of stress reduced ground cover, which was evaluated by digital photography and compared with ten spectral reflectance indices. On plots with a similar soil background, simple indices such as the …