2007 Annual Report 1a.Objectives (from AD-416) 1) Develop new and improved methods for evaluating the efficiency of soilless and/or hydroponic production practices and evaluate soilless media components such as water-holding gels, composts, wetting agents, and biocontrol agents for utility and quality. . 2)Develop new and/or improved methods for controlling pests, pathogens and/or abiotic stresses in ornamental and vegetable crops grown in soil-less culture in greenhouses. The effects of temperature-different day and night temperatures will be tested to improve the use of greenhouse environmental computer controls that will result in improved cultural methods and to broaden the knowledge of injury to floricultural crops due to micronutrient stress, other abiotic stresses, pathogens or insects encountered during soilless media culture. 1b.Approach (from AD-416) Soilless media components such as peat, hydrogels, wetting agents, composts and bio-control agents that represent the range of classes of substrates will be acquired and physical parameters, including but not limited to pH, water holding capacity, structure, and charge will be measured individually as mixtures of media before, during and after production. Plants grown in these mixtures will be evaluated both non-destructively and destructively in terms of growth rates and flower longevity including post-harvest performance in different environments and pot types. Plant growth and development will be evaluated non-destructively with digital cameras and infrared transducters in a range of environments. Research will also evaluate existing sensor technologies including spectroradiometers, digital cameras, and perhaps infrared transducers for macroelements, and explore molecular approaches to identify both broad and specific micro-nutrient stresses. The use of non-essential, beneficial elements such as silica, and essential elements such as potassium and nitrogen will be evaluated for their role in predisposing plants to biotic stress or prevention of biotic and abiotic stress in a wide range of bedding plants in different stages of growth. Plant growth and development will be evaluated at destructive harvests using digital imaging. Uptake and distribution of nutrients will be evaluated with destructive harvests, ICP plant tissue analysis, scanning electron microscopy, and energy dispersive X-ray analysis. 3.Progress Report Hydroponic studies were continued to identify the range of ornamental species that could be demonstrated to take up and accumulate silicon. SEM-EDXA was used to identify localized silicon “deposits” and to quantify amounts of silicon in the plant tissues. Studies are on-going to elucidate the interaction between silicon nutrition and foliar disease development in zinnia and phlox. Evaluation of non-destructive sensor measurements of plant tissues to develop correlations with plant health has demonstrated the relationship of leaf temperature with root disease. The expanded version of “Virtual Grower” (Beta. 2)has been developed and is currently being evaluated by cooperators and selected stakeholders in order to refine the version prior to general release. Commercial sources of water-holding polymers and planting media have been tested for the presence of “free” acrylamide using a liquid chromatography mass-spec – mass-spec methodology developed for this project. Results to date have shown that detectable levels of the carcinogen acrylamide can be released. Phosphorous stress in geraniums has been demonstrated to cause sudden, large pH declines in solid root substrates as well as hydroponically grown crops. A similar decline was shown to be caused by high temperature. Nutritional studies were conducted with cyclamen to determine the sensitivity of this crop to both major and minor nutrients. Symptoms were critically described and documented and tissues analyzed to better define sensitivities. Protein expression to boron stress was completed in geranium as a follow-up to previous studies with Arabidopsis. Photosynthetic function at two light levels was tested under boron deficiency conditions and confirmed that photosynthesis is an early target of boron stress. Boron stress can be delayed with higher light levels suggesting that carbohydrate status within a plant might help to mitigate boron stress symptoms. Work has begun on cloning most of the individual genes in two related geranium viruses, Pelargonium flower break and Pelargonium line pattern, with the hope of studying the interaction of the two viruses in Arabidopsis. Research has also been initiated to examine the potential effects of silicon nutrition on virus infection in geranium. 4.Accomplishments Completion of “Virtual Grower” version Beta 2. Greenhouse managers would be greatly benefited in decision making by a tool which would provide the user with the ability to “reconstruct” his growing facility within the model and then evaluate the impact of various modifications. The “Virtual Grower” software model was expanded by the addition of more weather site inputs, conservation potentials for energy curtains, and plant growth models. A Beta 2 version was distributed on CD for evaluation to numerous cooperators and end users. This information should enable decision-making to be done which will lead to enhanced profitability and competitiveness for the greenhouse production segment of agriculture. This accomplishment addresses the NP-305 components “Integrated Production Systems” and “Agroengineering, Agrochemical, and Related Technology.” 5.Significant Activities that Support Special Target Populations Greenhouse producers and farm market operators for ornamental and vegetable crops have been included in Liaison Committee activities which provide assistance in understanding grower needs, provide a mechanism for technology transfer, and give credibility to the research mission. 6.Technology Transfer Number of non-peer reviewed presentations and proceedings 6 Number of newspaper articles and other presentations for non-science audiences 3 Review Publications Frantz, J., Locke, J.C., Pitchay, D. 2007. Improving Growth of Calibrachoa x Hybrida (Cerv.) in Hanging Pouches. HortTechnology. 17:151-272. Pitchay, D., Frantz, J., Locke, J.C., Krause, C.R., Fernandez, G. 2007. Impact of Applied Nitrogen Concentration on Growth of Elatior Begonia and New Guinea Impatiens, and Susceptibility of Begonia to Botrytis cinerea. Journal of the American Society for Horticultural Science. 132:193-201.