Identifier

etd-04042007-213813

Degree

Master of Science (MS)

Department

Plant Pathology and Crop Physiology

Document Type

Thesis

Abstract

Transplants of Spartina alterniflora Loisel. (smooth cordgrass, Poaceae) are effective in stabilizing and protecting vulnerable coastal wetlands from erosion. However, the expense and labor associated with propagation and transplanting restrict the widespread use of S. alterniflora in coastal restoration and protection projects. As an alternative, seeding of S. alterniflora by aircraft has been proposed as a more useful and economical approach for revegetating denuded marsh sites. However, a period of stalled growth, which lasts for 12 or more weeks, has been observed in smooth cordgrass seedlings, and this increases their susceptibility to being washed away by inundating tides. This stalled growth period must be overcome before aerial seeding can be implemented. As with any plant species, it is reasonable to assume that S. alterniflora has optimal nutritional requirements for seedling and mature plant growth. Previous nutritional research has involved only mature smooth cordgrass plants. These studies showed that applications of nitrogen and phosphorus fertilizers increased plant growth. The objectives of this study were to document the lag phase of seedling growth observed in field and greenhouse conditions; determine the possible role of soil microbes, including seed and seedling pathogens and mycorrhizal fungi, as a cause of delayed seedling growth; and investigate the role of nutrition in seedling growth. This study confirmed the existence of stalled seedling growth in S. alterniflora and concluded that pathogens are not the cause of this lag period. Furthermore, supplemental N and P (240 kg N ha-1, 49.5 kg P ha-1) reduced the lag phase from over 100 days to less than 50 days under ideal greenhouse conditions. However, nutrient additions did not completely overcome stalled seedling growth. Future research possibilities include investigating the effects of plant growth regulators (hormones) and seed preconditioning treatments on seedling growth.

Date

2007

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Raymond W Schneider

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