Project Number: 3607-21000-015-00
Project Type: Appropriated

Start Date: Dec 10, 2008
End Date: Dec 09, 2013

Objective:
Objective 1: Evaluate plant nutritional requirements to optimize production and enhance quality. Sub-objective 1a: Elucidate the optimal tissue concentration of P and B in different light environments for major production species and how their susceptibility to foliar and root pathogens are influenced by nutrient status and light. Sub-objective 1b: Determine the uptake, accumulation, and potential benefit of silicon in ornamental crops and explore the potential for its use as a buffer to Cu toxicity and an alternative approach to pathogen control. Objective 2: Develop new and/or improved methods to detect, quantify, and manage biotic and abiotic stresses in ornamental crops grown in soilless and/or hydroponic greenhouse culture. Sub-objective 2a: Evaluate the use of existing non-destructive sensor technology and develop new molecular probes to measure and predict the impact of biotic and abiotic stresses on ornamental crops. Sub-objective 2b: Improve the Virtual Grower software model to enable growers to optimize their production systems by making more informed economic decisions about energy use, plant growth, pest management, and other production inputs. Objective 3: Evaluate existing and alternative growth medium amendments to determine the potential to deliver Si and buffer pH without negatively impacting beneficial microorganisms or crop growth.

Approach:
Impatiens, geranium, vinca, and zinnia will be grown in media amended with different concentrations of phosphorus and boron under different light environments to determine optimum supply and tissue concentrations of these nutrients. Plants containing different amounts of these nutrients will then be inoculated with Pythium, Phytophthora, Botrytis, and powdery mildew to determine host susceptibility. These same plant species will also be grown with supplemental silicon in the fertilizer solution or incorporated into the substrate as rice hulls or Si-containing slags, and inoculated with the same pathogens or expose them to elevated Cu concentrations in the rootzone to determine if Si plays a role in a plant¿s ability to withstand pathogen attack and Cu toxicity. Plants grown in different amounts of light and exposed to the aforementioned pathogens will be monitored with various sensors (e.g. digital cameras, infrared temperature probes, fluorometers, chlorophyll meters) and molecular tools to detect initial onset of stress symptoms. Finally, the production methods developed within these tests can be incorporated into the existing computer decision support software Virtual Grower to help growers make decisions in crop management.