Duration: 10/01/2008 to 09/30/2013

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

Statement of Issues and Justification

Issues and Justification

USDA Economic Research Service data (2006) show the size of the greenhouse/nursery industry in the US as $16,891,934,000, which was 7.1% of the value for all US commodities. Unfortunately, the data do not distinguish between greenhouse and nursery production. Nevertheless, the 2006 data shows that the greenhouse/nursery industry in the current twelve NE-1017 member states (AK, AZ, CT, GA, KY, ME, NE, NJ, NY, OH, PA, and TX) generated approximately $4,239,580,000 in sales (approximately 25.2% of all sales in greenhouse/nursery nationwide). Three of the twelve member states (AK, NJ, and CT) have greenhouse/nursery sales ranked the highest of all agricultural commodities within that state. It is clear that this segment of the agricultural industry is of significant importance throughout the NE-1017 member states.

Academic support for commercial greenhouse production (also known as controlled environment agriculture) has, through NE-1017, brought together a unique mix of plant scientist and engineers interested in improving the economic viability of this important segment of agricultural production in the US. The challenges faced by individual researchers include limited funding sources, limited availability of (expensive) research facilities, and limited support through individual Experiment Stations. Through collaborating in a Multi-State project, researchers are able to work on subcomponents of larger research questions and later combine their results to provide solutions to the greenhouse industry.

NE-1017 members continue to conduct needs assessment from their stakeholders through several methods, including grower input, observations at grower operations, tracking issues related to grower questions, and presentations and discussions at various state, regional and national meetings. Based on grower inputs, evaluation of skills and interests of project members, and the available facilities, the project members have identified five high priority topics to address over the next 5 years. They are (1) energy conservation and alternative energy sources, (2) water and nutrient solution management, (3) sensors and control systems, (4) environmental effects on plant composition, and (5) natural ventilation design and control. These issues are discussed separately in each of the following paragraphs. The objectives for these topics are all technically feasible based on current knowledge, past work, and available expertise and facilities.

Topic 1: Energy conservation and alternative energy sources

Justification: As oil prices approach $100 per barrel, rising energy costs are clearly a concern for greenhouse growers. Strategies to reduce energy consumption, particularly for heating, include management, maintenance and, where justified, investment for upgrades of facilities and equipment. Potential conservation practices include: (1) management strategies that enable growers to lower air temperature without compromising their crops, (2) maintenance of structures and equipment, (3) mechanization or other measures that increase space utilization within the greenhouse, (4) upgrading control systems and strategies that improve uniformity and reduce unwanted fluctuations in temperature, and (5) insulation of greenhouse structures in areas where light reduction will not impact production, as well as insulating heating pipes in the boiler room and where they transport heat through areas that do not require heating. Continued research and guidance is needed to assist growers in implementing the most appropriate and economical conservation methods.

In addition to energy conservation measures, growers are increasingly interested in the use of alternative fuel sources (biomass, waste, wind, solar, etc.). New technologies and applications are becoming available continuously and new research is needed to evaluate these technologies for commercial greenhouse applications.

Topic 2: Water and nutrient solution management

Justification: Nutrient delivery systems consist of the hardware components that transport nutrient solution (water and soluble fertilizer) from a central location to each individual plant according to predetermined specifications. Irrigation frequency and duration may be based on fixed time intervals determined from past grower experiences, or be more specific to plant demands. Examples of nutrient delivery systems include drip, ebb and flood, overhead, capillary mat, aeroponics, and hydroponics. Optimizing the management of nutrient delivery systems, through control of electrical conductivity, can ensure plants are only provided the fertilizer concentration needed for healthy growth, without risk of nutrient deficiencies or the potential for nutrient toxicities and fertilizer runoff that result from fertilizer over-application.

In all nutrient delivery systems, recycling of the nutrient solution to eliminate contamination of the environment is possible, but such practices require a high level of management of nutrient concentrations and water supply. Closed irrigation systems pose several unique challenges: (1) a large storage container is needed to collect the drain water and to store the solution volume needed for the next irrigation cycle, (2) the system needs to be properly designed to prevent any leaks, (3) the potential exists for disease organisms to spread rapidly throughout the entire solution volume, (4) unwanted residues (e.g., from chemical applications) can accumulate over time, (5) nutrient settling and aeration, and (6) closed systems may be more expensive to install and maintain. Despite these challenges, many growers are highly interested in closed irrigation systems because of the belief that future regulations will restrict the practice of uncontrolled discharge of nutrient solutions to the environment. Growers are asking for systems that will recycle the nutrient solutions without risking the spread of disease while maintaining good nutrition management and avoiding toxicity.

Without continued research on managing water and nutrients, growers are going to be forced into expensive waste water treatment systems, are going to face challenges of growing plants in less than ideal conditions because of limited availability of water, or be forced out of business.

Topic 3: Sensors and control systems

Justification: It is important to accurately measure and interpret the greenhouse environment in order to provide an optimum environment throughout a cropping cycle. Growers use a range of sensors and control systems, from manual control all the way to sophisticated computer control. Sensors and control systems are continuously developing and their installation and use often require a significant investment in time and money. As a result, many growers would benefit from improved sensors and control systems at their operations if they had the appropriate decision tools that help them determine what the best options are for their operations. Such decision tools (e.g., summaries of evaluations and/or trials) can be generated by research projects conducted by NE-1017 members.

It is likely that both consumers and legislators will continue to be interested in sustainable and organic plant production. In greenhouses, sustainability should include efficiently utilizing resources including electricity, fuel for heating systems, water, and nutrient systems. One method to do this is to improve sensor technology and design and improve grower decision making capability with respect to greenhouse heating, lighting, irrigation, and fertilization.

Topic 4: Environmental effects on plant composition

Justification: Research conducted by NE-1017 members has the potential to make contributions to the fields of genetic engineering and human health. By manipulating the plant environment, it may be possible to stimulate specific gene expressions in plants, or increase the production and/or the quality of compounds important for the nutritional value of specific plants. In some cases, research in these areas is more easily fundable, resulting in new collaborations and new knowledge generation. Some NE-1017 members have already collaborated in such research projects and additional projects are in the planning stages. Developments in these research areas have the potential to significantly increase the economic returns for greenhouse operations involved in crop production for plant compound generation.

By manipulating the plant environment, it is possible to increase the production and/or the quality of specific compounds important for the nutritional or industrial value of specific plants. In some cases, research in these emerging areas is more easily fundable, resulting in new collaborations and new knowledge generation. Some NE-1017 members have already collaborated in such research projects and additional projects are in the planning stages. Developments in these research areas have the potential to significantly increase the economic returns for greenhouse operations involved in crop production for plant compound generation.

Controlled environments provide a unique opportunity to modify product quality attributes or more specifically, concentrations of selected phytochemicals in plants. An example of such approach is lycopene in tomato. It has been reported that light quality and intensity (e.g., Alba et al., 2000), air temperature (e.g., Krumbein et al., 2006), nutrient concentration (e.g., Fanasca et al., 2006), and salinity level of nutrient concentration (e.g., Krauss et al., 2006) affected lycopene concentration in fruit. Another example in enhancing secondary metabolites of Hypericum perforatum or St John's wort, a medicinal crop produced worldwide, and the reported factors affecting its active medicinal compounds include light quality and intensity (Briskin and Gawienowski, 2001), air temperature (Couceiro et al., 2006), and others (Murch et al., 2003). In floriculture, it has been observed that flower pigment concentrations were affected by greenhouse environments, but limited amount of research has been conducted for environmental factors on flower color, also driven by altered concentrations of phytochemicals. However, practical information on manipulating various phytochemicals as affected by environmental conditions and cultural system/practices is limited.

Another emerging area relevant to this approach is biopharmaceutical and other high value protein production using plants and other photoautotrophic organisms (algae and bacteria) including transgenic organisms. Specifically, whole plant based production is advantageous over more traditional systems using microbes or mammalian cells (Twyman et al., 2003). However, genetic, cultural and environmental factors to enhance biopharmaceutical production have not been well investigated, although optimization of the production is critical in commercialization of such products. Such effort of optimization must be done in a collaborative format including fundamental and applied researchers consisting of biologists, applied horticulturists, and engineers through strong linkage between academic researchers and industry R&D groups.

The controlled environment agriculture (CEA) is an integrated technology to maximize the productivity of plants and considered as a sustainable platform of producing phytochemicals, biopharmceuticals and other high value products. In CEA, all growth parameters can be controlled and the plants can be kept free of pesticides since most pathogens and diseases can be addressed using integrated pest management techniques in the contained environment. We propose to take advantage of this combined expertise of horticultural sciences, plant biotechnology, and greenhouse engineering to develop a potential foundation for a new industry, and greenhouse design and technology suitable for high quality products and plant high value compound production such as phytochemicals and biopharmaceuticals.

Topic 5: Natural ventilation design and control

Justification: Natural ventilation of greenhouses involves the use of sidewall and/or roof vents to cool the air and reduce humidity. Reducing heat stress and diseases caused by high temperature and humidity have a direct effect on the profitability of the greenhouse operation. The control of the ventilation vents and heating systems has evolved as control technology has evolved. Today, several companies provide computer control systems that will operate natural ventilation and heating systems based on a variety of control strategies, sensor inputs from the plant area as well as weather conditions.

Today's advanced greenhouse industry is developing into sustainable crop production systems with reduced energy consumption, and higher crop yields and quality. Properly designed ventilation systems are essential for the optimal control of air temperature, humidity and maintaining optimum concentrations of gases in greenhouse environment. Thus, photosynthetic and transpiration processes of plants are regulated properly and the quality of crops is improved. The ventilation process is critical for cooling and for reducing humidity levels within the greenhouse. Reducing heat stress and diseases that are caused by high humidity levels has a direct effect on the profitability of a greenhouse operation. Greenhouse cooling is essential for controlling the physiological response of a crop which is directly related to yield and production quality. Due to advantages such as low energy consumption, less operational cost, less maintenance, less noise, there has been a major shift back to the utilization of natural ventilation. However, the physical phenomena involved in natural ventilation and designing a naturally ventilated greenhouse are complex and appropriate control strategies are needed to ensure uniformity, production quality and energy efficiency.

Related, Current and Previous Work

Topic 1: Energy conservation and alternative energy sources


OH and NJ have initiated a joint effort to evaluate the feasibility of capturing exhaust heat from greenhouses during the day for nighttime heating during early spring and late fall seasons. This effort is ongoing.


NJ has developed simulation tools using a spreadsheet approach to evaluate energy use and conservation strategies for greenhouse locations that have access to hourly weather data collected over at least an entire year. So far greenhouse locations in Taiwan, Japan, Canada, NJ, Ohio, and AZ have been evaluated. In addition, heat pumps, fuel cells, and hot water storage systems were included in some of the case-studies examined (Both et al., 2005; Both et al., 2007).


NJ: A 250 kW landfill gas fired microturbine installation is under way at the NJ EcoComplex research greenhouse facility. The system will generate heat and electricity for the 1-acre greenhouse facility. Excess electricity will be sold back to the local utility grid.


In NJ, a multidisciplinary effort was conducted to evaluate the available bioenergy potential and conversion technologies (Brennan et al., 2007).


MI: Funded by the Michigan Floriculture Growers Council, Extension materials were developed addressing energy conservation issues for commercial greenhouse production. These materials as well as other energy related outreach information are available online at: http://www.hrt.msu.edu/Energy/Default.htm. Several of NE-1017 member states have contributed to this effort.


Topic 2: Water and nutrient solution management


Subtopic 1. Develop and evaluate methodologies.


AZ used experimental data and modeling approaches to quantify stomatal resistance, transpiration rate and leaf temperature of tomato in response to environmental conditions and salinity (Ishi et al. 2006; Kubota et al. 2006). The ability of reflectance sensors to detect plant response to electrical conductivity (EC) treatments was evaluated.

In an on-going collaborative research effort, GA and ME determined plant water use of herbaceous perennials when crop were watered based on plant need using capacitance sensors (Nemali et al. 2006, 2007; Scoggins and van Iersel, 2006; van Iersel et al., 2006). Plants irrigated at lower set points had shorter and fewer branches and lower shoot dry weights. However, plants irrigated at set points ranging from 0.25-0.35 m3/m3 were all of acceptable and equivalent quality.


KY characterized evapotranspiration of nutrient film technique grown lettuce in a collaboration with Brazilian colleagues (Zolnier et al. 2003, 2004). Evapotranspiration was found to be strongly influenced by light level and air vapor pressure deficit (VPD) in naturally ventilated greenhouses with moderately warm to hot growing conditions.


TX studied the morphological and physiological responses of four herbaceous perennial species subjected to two subsequent drought cycles (Starman and Lombardini, 2006). In general, substrate water content averaged 0.60 mm3/mm3 for control and 0.15 mm3/mm3 for drought treated plants. Overall, plant growth and development continued even when substrate water content was reduced to 0.13 mm3/mm3. Drought had less effect on net carbon assimilation rate than transpiration rate and stomatal conductance, which caused a general increase in leaf-level water use efficiency.


NY measured crop evapotranspiration in hydroponic production systems so that environmental control faults or problems could be detected (Ferentinos and Albright, 2003; Ferentinos et al., 2003; Mathieu, 2004). Lettuce crops were grown with continuous and batch deep flow hydroponic systems, and evapotranspiration was modeled with the Penman-Monteith equation (Dayan et al., 2005).


OH used load cells to measure and log changes in weight of potted plants with controlled moisture tension in the potting medium. Evapotranspiration was measured and compared to potting medium moisture tension based on weight loss between irrigation events to measure lag time of the sensors (Prenger, 2003; Prenger et al., 2005). Volumetric water content (VWC) targets of 20, 30 and 40% were used. Dry matter increased as the VWC targets increased but water use efficiency decreased.


OH developed and refined the use of remote sensing to evaluate plant stress (Buenrostro-Nava et al., 2005; Kacira et al., 2005; Yang and Ling, 2004).


Subtopic 2. Evaluate the entire fertigation system, including water delivery, plant uptake, and runoff, while accounting for optimization of micronutrient, media pH, and EC levels.


AZ manipulated the environmental factors which affect transpiration, both at the canopy level (potential transpiration), and at the root level (electrical conductivity, EC), to change photoassimilate distribution between source [leaves] and sink [fruits] to steer the plant towards more vegetative or more reproductive growth (Wu. 2006; Wu et al., 2004). A project with hydroponically-grown sweet potato (Ipomoea batatas) by Japanese and AZ researchers monitored concentrations of critical individual chemical species over time in the hydroponic solution to provide for optimal nutrient management (Ono, 2001; Ono et al., 2003).


GA observed physiological responses to different substrate water contents (Burnett et al., 2006). There was little or no effect on leaf photosynthesis and no correlation between plant growth and leaf photosynthesis. Leaf elongation was very sensitive to water availability in the substrate. When plants are exposed to drought, leaf elongation was inhibited, thus reducing the total area of leaves for photosynthesis.


GA studied the effects of high salinity levels (either from NaCl or by using high fertilizer concentrations) on the physiology and morphology of tomato (Montesano and van Iersel, 2007). High salinity levels reduced plant height, dry weight, and leaf elongation. High levels of NaCl (but not high fertilizer concentrations) reduced leaf chlorophyll and photosynthesis and the maximum quantum yield of photosystem II.


KY used selected commercial organic fertilizers to grow bibb lettuce in a pond production system. Water soluble materials derived from algae (Algamin and EcoNutrients) had little value as an organic fertilizer for lettuce in a tank hydroponic system. Water tests showed very low nutrient values in these fertilizer solutions. Dry weight of lettuce grown with a formulated organic fertilizer (Omega) was similar with Red Sails lettuce or significantly lower with Ostinata lettuce than lettuce grown in inorganic fertilizer.


NH developed a model of pH in container growing media based on surveys of physical and chemical qualities of commercial propagation media, quantified lime reactivity and residual (unreacted) lime in container media, micronutrient levels in both fertilizer and contaminant sources (Smith et al., 2004; Wik, 2003). Tissue and media nutrient levels were quantified from the stock plant stage through to propagation for vegetatively-propagated cuttings, as was leaching of nutrients during propagation.


NY measured the relationship between tip burn, which is a marginal necrosis of the rapidly expanding young leaves of lettuce caused by a localized Ca deficiency, as affected by root pressure, and vapor pressure deficit. A modeling approach was used to investigate the relationship between nitrate and carbon as osmoticum for lettuce crops (Linker et al., 2005; Mathieu et al., 2006).


OH observed that nutrient solution of fertilizer protocols affected plant composition in a way that altered biomass partitioning and insect herbivory (Glynn et al., 2003; Hale et al., 2005)


PA varied the placement of osmocote for growth of three species, and pour-through tests determined the amount of salt that could be leached from the media. Initially, the amount of salt leached was least with top placement and greatest with bottom placement. After 5 weeks of growth, all pour-through values were similar. Bottom placement of Osmocote tended to produce smaller plants and higher EC values of the pour-through compared to other placements. The EC of the soluble fertilizer leachate was about twice the value of the Osmocote leachate. PA noted excessive salts were leached from Spent Mushroom Substrate (SMS) (Heinmann et al., 2003; Holcomb et al., 2005).


Subtopic 3. Improve design of water and nutrient recirculation systems.


AZ recovered water from the stream of the exhaust air of the greenhouse equipped with a fan and pad evaporative cooling system. An energy balance model of the condenser was validated by data obtained using a condenser unit placed under a semi-arid greenhouse condition (Sabeh et al., 2006; Sase et al., 2006). Compared to water use by plant canopy transpiration during a pre-monsoon day and monsoon day, respectively, the model simulated that 26.9% / 9.2% and 15.1% / 6.2% of water could be recovered in pre-monsoon day and monsoon day, respectively, when equipped even with the relatively inefficient condenser units. With a condenser efficiency of 50%, the proposed system could recover 100% / 57.6% of irrigation water during pre-monsoon days and 94.3% / 38.4% recovery during monsoon days.

AZ used a slow sand filter (SSF) with 3.3 m2 of surface area to treat nutrient solution drainage from the greenhouse hydroponic system. The primary goal was to improve the performance of the SSF by maintaining the Shmutzdecke layer with mechanical cleaning methods.


CT developed a Partial Saturation Ebb and Flow Watering System (PSEFW) to restrict the uptake of water by limiting the contact time of the solution with the base of the pots. The supply interval could be varied from 2 to 12 minutes. In practice, a minimum of 30% of maximum volumetric water capacity (VWC) and a maximum of about 70% VWC were the limits to adding water with a single watering cycle of the PSEFW system. When crops were watered repeatedly by PSEFW, a difference in VWC was maintained from one watering cycle to the next. Using a long duration intended to saturate the pots VWC was 43 to 46% at the start of watering, and 89 to 94% at the end of watering. In comparison, VWC was 20 to 35% at the start of watering, and 60 to 74% at the end of watering with the short duration intended to partially water the pots.


NY examined the fates and effects on plant nutrition of three chelators, ethylenediaminetetraacetate (EDTA), diethylenetriaminepentaacetate (DTPA), and ethylenediaminedisuccinate (EDDS). The EDDS concentration decreased rapidly within 7 days, most likely due to biodegradation. EDTA and DTPA concentrations stayed steady throughout the experiments despite additions to maintain a constant volume. Loss of chelator may have been due to either plant uptake or photodegradation of the chelator. Low concentrations of EDTA and DTPA were found in both root and shoot tissues, but these did not account for the amount of chelator lost from the system. A comparison of Agrifoam and Oasis growth foams, and Grodan, an expanded rockwool substrate, focused on pop-outs during lettuce seedling development and growth within 10 days from seeding (Montgomery, 2005).


NY examined pond or deep-flow hydroponics for continuous production of salad spinach with nutrient solution that was replenished but not changed out for many crop cycles. Pythium aphanadermatum caused a devastating root disease at warm temperature, but at cool temperature it was prevented (Katzman, 2003). Both UV and filtration mitigated immediate effects of inoculation compared to inoculation with no treatment, but a severe chronic disease process was established eventually. UV treatment led to lack of iron availability in deep flow hydroponics, because daily additions of water and nutrients were small.


Topic 3: Sensors and control systems


CT, NY, NE, OH, AZ, KY, NJ have compared actual plant water use of tomato, salad greens and ornamental plants to evapotranspiration models which require sensors to measure temperature, relative humidity, and other environmental parameters. Researchers have used sensors to measure plant and substrate water status.


OH is improving the accuracy of volumetric water content (VWC = volume of water ÷ volume of substrate) sensor measurements to reduce the effect of sensor placement on measurements. Work also has determined the lag time between the moment water is added to the container at the surface until the sensor detects additional moisture. OH irrigated container grown plants when VWC sensors measured water contents of 20, 30, and 40% plus or minus 5%. Plants irrigated at higher VWC set points had greater stem, root, and leaf dry mass but lower water use efficiency compared to those irrigated at lower VWC set points.


OH has measurement experience with three types of volumetric water content sensors: (1) tensiometers [Irrometer], (2) the WET sensor [Dynamax] and (3) the HydroSense [Campbell Scientific]. A state-of-the-art weather station was recently installed in an outdoor landscape nursery lab that will accurately sense ambient temperature, relative humidity, wind speed and solar energy. These measurements can be used for inputs to evapotranspiration models as an alternative for deciding "when to irrigate." This unit is designed to work in conjunction with a newly installed Argus Nutrient Delivery System.


NY has initiated research to improve the accuracy and sensitivity of lettuce growth models through precise monitoring of the morphological and physiological characteristics of each leaf's growth. The methodology to extract the required information is under development.


NY is improving supplemental lighting system design for greenhouse crop production using a Cornell University developed genetic algorithm technique. The approach uses evolutionary parallel search capabilities of genetic algorithms to design the layout of luminaires, their mounting heights and wattages.


NY has two patents relating to light and carbon dioxide controls in greenhouses:

Albright, L.D. Method for controlling greenhouse light. United States Patent 5,818,734. October 6, 1998.

Albright, L.D., K.P. Ferentinos, I. Seginer, J.W. Ho and D. de Villiers. Systems and methods for providing optimal light-CO2 combinations. United States Patent 7,184,846, February 27, 2007.


ME and GA are working with a capacitance sensor automated irrigation system and various other moisture sensors to improve the efficiency of greenhouse irrigation. GA developed this system which uses capacitance sensors to improve the frequency and accuracy of substrate moisture content measurements. Using this system, herbaceous perennials (Gaura lindhiemeri, Coreopsis verticillata, and Veronica Sunny Border Blue) and annuals (Petunia × hybrida, Catharanthus roseus, and Salvia splendens) were irrigated with as little as 1-2 L of water throughout the entire production cycle. No non-point source pollution from fertilizer leachate is released when plants are irrigated with this irrigation system. In addition, GA determined that the area of the uppermost fully expanded leaf of Petunia × hybrida correlates to substrate volumetric water content. Thus, leaf area may be used to detect early symptoms of drought stress in commercial greenhouse production.


NE has used and developed sensors which measure greenhouse environmental variables including temperature and relative humidity. These sensors may be used to inexpensively monitor greenhouse environment and at NE are also used to teach future agricultural engineers about sensors and greenhouse engineering.


GA tested a variety of VWC sensors including the EC-5 and EC-TE (Decagon Devices), Moisture Clik (Dynamax, Inc.), and the Theta Probe (Delta-T Devices) to determine whether substrate electrical conductivity or temperature affect volumetric water content measurements from these sensors. The EC-5, EC-TE and Moisture Clik are reliable, inexpensive VWC sensors that are appropriate for nearly continuous monitoring and irrigation control. The Theta Probe is a more expensive, hand-held model that could improve growers ability to make irrigation decisions, but this sensor would not be appropriate for irrigation control. GA is developing a system which integrates measurements of electrical conductivity and volumetric water content to automate both irrigation and fertilization. This system will use EC-TE sensors developed by Decagon Devices in Pullman, WA.


Topic 4: Environmental effects on plant composition


AZ demonstrated a technique to increase lycopene concentration in tomato fruit by applying moderate level of osmotic/saline stress to the hycroponic root zone. Fruit quality attributes of tomato monitored for 2 years (total of four cycles each with 6-7 months), as a part of an intervention study on consumption of fresh tomatoes, showed that the high electrical conductivity of the nutrient solution, increased by adding sodium chloride was the primary factor increasing lycopene concentration either in dry or fresh weight basis, regardless of the other environmental variables inside the greenhouse associated with seasonal changes outside the greenhouse. Lycopene was also positively correlated to daytime mean air temperature and daily PAR, respectively (Kroggel et al., 2007). In addition to lycopene, we have also observed a significant increase in carotenes, phenolics and vitamin C concentrations on a fresh weight basis but no significance on dry weight basis. This indicates that these compounds were enhanced as a result of 'concentration effect' due to the limited water flux to the fruit under the high osmotic stress. However, increased lycopene concentration under high EC was considered as an environmental stress driven response as suggested in a separate experiment, testing varied application timings of high EC (Wu and Kubota, 2008).


AZ: As a part of on-going project to develop a novel production and delivery system for edible vaccines and other high value proteins, AZ evaluated the expression of a Y. pestis F1-V antigen fusion protein in a tomato line, developed by Alvarez et al. (2006), as a model system. To evaluate the protein productivity in greenhouse, selected transgenic tomato lines were grown using commercial hydroponic production practices and its expression of f1-v gene and protein content are under quantification.


CT studied use of shade to optimize production of high-quality greenhouse tomato. Some amount of shade may be optimal to produce high quality tomatoes in a greenhouse during summer months in the northeast USA. Simultaneous comparisons were made in three years among greenhouses that were either not shaded, or covered with reflective aluminized shade cloth that attenuated 0, 15%, 30% or 50% of direct sunlight. The shade cloth was applied at the start of warm weather in early June and the houses were shaded for the rest of the summer. Total yield decreased linearly with increasing shade, but there was no difference among shade treatments in yield of marketable fruit in any of three years. Cracked skin was the defect most affected by shade. There was relatively little effect of shade on composition of fruit. The most dramatic effect of shade was on starch in leaf blades, which declined by about 25% under 50% shade. The concentration of other nutrients increased, primarily due to the change in dilution effect of starch on tissue composition.


NY examined various environmental factors to optimize secondary metabolites in Hypericum perforatum or St Johns wort. The effects of light intensity, light integral and light quality on the biomass and secondary metabolites hyperforin, pseudohypericin and hypericin were quantified and a cultivation protocol for maximum metabolite production in controlled environments was developed. Light integral was found to have a greater effect on total concentration of the desired metabolites than light intensity. Ultra-violet supplementation was evaluated a method of increasing metabolite concentration just prior to harvest and an optimal protocol was developed. An examination of plants grown in a field condition and in a controlled environment simultaneously showed a significant increase in chemical production for the plants grown under controlled conditions.


NY will start a new SBIR project involving environmental manipulation to increase production of valuable chemicals from GMO plants, preferably through chloroplast expression. NY is actively exploring GMO opportunities both pharmacological (though no good candidate has been idenfitied yet) and otherwise.


Topic 5: Natural ventilation design and control


During the past years, new research has been conducted to study airflow patterns and predict greenhouse interior climate variables using Computational Fluid Dynamics (CFD) techniques (e.g., Lee et al., 2002; Kacira et al., 2004; Khaoua, 2006; Fatnassi et al., 2006). It became possible to simulate the indoor and outdoor greenhouse environment and also evaluate better designs for vent configurations to improve control strategies.


Brocket and Albright (1987) developed a model for inlet control with natural ventilation based on the concept of neutral pressure level for agricultural buildings. This model is capable of making faster calculations and could be used to establish a real-time control strategy for natural ventilation systems in greenhouses. With the advancement in sensor technology, the pressure sensors are now commercially available and they are inexpensive. Therefore, real time measurements can be made to determine actual pressure coefficients for use in model simulations, and an improved control strategy could be developed as an alternative to existing vent control systems (e.g., LaFrance, 2005; LaFrance and Brugger, 2006).


The microclimate is influenced not only by the macroclimate but also by the physical state of the plants. The most energy efficient systems are those which have the most direct effect on the microclimate in the greenhouse (Bailey, 1985; Boulard, 2004; Kacira et al., 2004). Thus, understanding of interactions between the plants and their microclimate is significant to establish better control strategies in greenhouse plant production. Plant-response-based closed-loop plant production is a concept of using a plant's physiological status as a feedback to adjust environmental and cultural practices to improve plant growth and development.


The efficiency of evaporative cooling systems is higher in hot and dry climate regions, and these systems could also provide reasonable results in more humid environments (Montero and Anton, 1990; Montero and Segal, 1993). However, there has not been an adequate evaluation of the effects of fog cooling combined with natural ventilation on the greenhouse microclimate and dynamic plant responses to the changes in the greenhouse environment. Such research could also provide crucial information on establishment of appropriate climate control strategies for naturally ventilated greenhouses.


NJ has a fully operational and instrumented open-roof greenhouse system. Previous work in this facility (in collaboration with NIRE, Japan) included the development of a simple ventilation model (Sase et al., 2002). The same facility was used for a study of the incorporated floor heating system using numerical analysis techniques (Reiss et al., 2007).

Objectives

1. Evaluate biomass derived fuels for greenhouse heating
   
2. Develop decision support systems for alternative fuel heating systems
   
3. Develop protocols for irrigation that maximize water use efficiency while maintaining crop growth and quality
   
4. Develop irrigation protocols and filtration or sterilization methods for nutrient solution recirculation that minimize the effects of pathogens or toxic metabolites
   
5. Improve volumetric water content sensor efficacy
   
6. Improve sensor control of the greenhouse aerial environment (light, carbon dioxide, temperature, and moisture)
   
7. Develop greenhouse design and management protocols to maintain high nutrition values of vegetable crops grown under various environments
   
8. Develop greenhouse design and management protocols to maximize production of beneficial compounds such as phytochemicals and biopharmaceuticals
   
9. To continue our efforts to use CFD techniques to evaluate greenhouse natural ventilation systems
   
10. Continue efforts to improve the efficiency and effectiveness of greenhouse fog cooling systems
    
11. Improve control strategies as an alternative to existing vent control systems
    

Methods

Topic 1: Energy conservation and alternative energy sources 1. Evaluate biomass derived fuels for greenhouse heating. NE will investigate alternative biomass fuels for heating, as a supplement or replacement of propane and natural gas systems. This effort will utilize collaborator greenhouses equipped with biomass furnaces. It will develop and test anticipative and adaptive environmental control algorithms. NJ will perform cost comparisons between bio-fuels and fossil fuels (fuel oil, natural gas, and propane). These comparisons will include the different system and operational costs. Interdependence and coordination: NE will be the lead station. NJ will provide information pertaining to switchgrass and landfill gas. PA will provide information pertaining to shelled corn. Historic information is available (John Bartok, CT) and a greenhouse energy web site maintained by MI (http://www.hrt.msu.edu/Energy/Notebook.htm). NE will determine the combustible energy contents of various biofuels (supplied by various stations) using the ASTM bomb calorimetry test, and contribute to improvements to burner efficiency through sensors and controls. In addition, NE will maintain a web site on use and availability of biofuels for greenhouse heating, along with webinars on this topic. 2. Develop decision support systems for alternative fuel heating systems. NJ plans to develop a decision-support system for the microturbine installation currently in progress. The decision support system would help a grower manage such a distributed energy generator with the goal of optimizing the economic return from both the energy generation and crop production capabilities. In addition, NJ will include an economic analysis in the proposed development of the decision support system. Interdependence and coordination: NJ will be the lead station. PA will provide information pertaining to waste plastic as an alternative fuel source. CT will provide information about wood as an alternative fuel source. NE will assist in the decision support system development. Topic 2: Water and nutrient solution management 3. Develop protocols for irrigation that maximize water use efficiency while maintaining crop growth and quality. CT (New Haven) will use a short-duration watering refinement of ebb and flow watering of flooded floors to control the volumetric water content taken up in one watering. This technique will be used to determine the effect of water supply or water deficit on growth and quality of various potted ornamental species under commercial conditions. Some of the factors that will be examined are: 1. The amount of water and nutrients taken up in one irrigation cycle, 2. The distribution of water and nutrients in vertical layers of the root medium, 3. The growth and composition of the plant in response to limited uptake of water and nutrients, and 4. Quality of the crop during growth and when placed in a controlled post-production environment. GA will use soil moisture sensors to develop more efficient irrigation techniques for greenhouse crops. Different irrigation strategies, constant substrate water content versus fluctuating water content, will be compared for their effect on plant growth and quality, as well as water use and potential runoff of fertilizer. Real-time sensing of nutrient availability in soilless substrates will be developed using EC sensors or ion specific electrodes. This would allow fine tuning of greenhouse fertilizer applications, resulting in improved plant quality and reduced risk of fertilizer runoff. ME will use soil moisture sensor automated irrigation as a tool. This tool will be used to: a) Develop protocols to help commercial greenhouse growers convert irrigation control to sensor automated irrigation systems, b) Develop crop-by-crop irrigation guidelines for a variety of herbaceous ornamentals, and c) Determine how environmental factors, including light, impact plant water use. NY will determine the sodium, chloride, (bi)carbonates, and total conductivity threshold limits for several of the most common vegetative annuals grown using conventional (overhead) irrigation or sub-irrigation. Plants will be exposed to 5 different salt levels applied via overhead or sub-irrigation and container media and irrigation water will be monitored weekly for pH, electrical conductivity, and concentration of specific salts. Plant tissue will be analyzed for concentration of specific salts. A group of plants exhibiting a variation in salt tolerance will be exposed to the salt treatments in combination with treatments to ameliorate salt damage (such as calcium, potassium, or silicon additions). Plants will be measured for physiological response and additional indicators of salt tolerance (osmolyte production, antioxidative enzyme expression). OH will use an Argus Nutrient Delivery System designed to deliver water and nutrients accurately to research size treatment zones. Potting medium moisture content will be measured with tensiometers or based on evapo-transpiration measurements. The nutrient delivery system will be set up so water and nutrient recipes can be delivered to three different laboratories: (1) outdoor landscape nursery crops, (2) indoor greenhouse crops and (3) indoor hydroponic lettuce and/or herb crops. Crop recipes can be uniquely specified, precisely delivered and continuously monitored. PA will examine capillary water flow in commercial potting media. A simple method will be developed to measure this parameter of water uptake in ebb and flood systems, based on evaporation from a media surface. This method will be used to determine how various media differ in capillary flow rates. Media that vary in this parameter will be tested for performance in ebb and flood watering systems. NJ will analyze the costs of nutrient delivery systems and compare them to the costs of waste water treatment systems. Such an analysis will include the costs related to: " Converting from simple irrigation control to automated irrigation systems. " Larger storage container(s). " Managing system to avoid leaks. " Added disease control. " Nutrient settling and aeration. " Installation and maintenance. " Changes in crop quality. " Additional management costs. Interdependence and coordination: CT will be the lead station. GA will provide information pertaining to the use and effectiveness of volumetric water content (VWC) sensors. ME will provide information pertaining to the use of VWC sensors in automated irrigation systems, and depends on work done in GA. OH will provide information pertaining to single nutrient dosing systems, as well as non-contact plant water status monitoring techniques. 4. Develop irrigation protocols and filtration or sterilization methods for nutrient solution recirculation that minimize the effects of pathogens or toxic metabolites. CT will infest pots of ornamental plants on flooded floors and test various methods to prevent spread of disease from plant to plant due to the use of a common reservoir of recycled nutrient solution for ebb and flow watering. Filtration methods such as ladder filter, cloth filter, and sand filter will be used to clean the solution and thus retard spread of disease. Sterilization methods such as copper ionization, and injection of hydrogen peroxide, or ozone, will be tested as methods to sterilize solutions before use in the next irrigation event. The efficacy of these methods will be determined in two ways. The spread of disease will be documented in terms of the number of plants that develop disease symptoms and the rate at which these symptoms appear. A large volume of nutrient solution will be filtered and the filters cultured on selective growth media to quantify the density of disease organisms in the nutrient solution. CT will grow tomato or lettuce in nutrient solutions that are either used once or recirculated. Plant tissues, as well as nutrient solutions will be analyzed to see which ions build up in solution and affect the composition of the plants due to recirculating nutrients. Throughout these studies, the solutions will be modified and tested as required to prevent unnecessary imbalance of the nutrients required for growth. NY will characterize root exudates (phenolics, organic acids) in sub-irrigation systems and determine toxicity thresholds for affecting plant growth; and test systems such as activated charcoal, slow sand filtration, and beneficial bacteria for their ability to remove toxic compounds in recirculating water systems. Irrigation water samples will be collected periodically and subjected to resin extraction and analysis via GC-MS and LC-MS to identify organic acids, phenolics, and higher molecular weight compounds. Several compounds will be screened for toxicity either singly or in combination through a bioassay. Filtration methods such as activated charcoal, slow sand filtration, or bacterial removal will be tested for their efficacy. OH will construct a hydroponic growing system for lettuce and/or herbs to evaluate dissolved oxygen and nutrient recycling issues and their impact on plant production and plant disease. Interdependence and coordination: CT will be the lead station. NY will provide information pertaining to root exudates. OH will provide information pertaining to the dissolved oxygen concentration of the nutrient solution. NJ will provide information pertaining to its experiences with a recirculating ebb and flood floor irrigation system. Topic 3: Sensors and control systems 5. Improve volumetric water content sensor efficacy. OH has measurement experience with three types of volumetric water content sensors: (1) tensiometers [Irrometer], (2) the WET sensor [Dynamax] and (3) the HydroSense [Campbell Scientific]. All three sensors are available for use. A state-of-the-art weather station was recently installed in an outdoor landscape nursery lab that will accurately sense ambient temperature, relative humidity, wind speed and solar energy. These measurements can be used for inputs to evapotranspiration models as an alternative for deciding when to irrigate. This unit is designed to work in conjunction with a newly installed Argus Nutrient Delivery System. ME: Moisture sensors may be used to automate irrigation or provide growers with more reliable estimates of VWC for manual irrigation. However, sensors vary in their sensitivity to electrical conductivity and temperature as mentioned previously. One goal is to test the accuracy and reliability of moisture and/or sensors for automation of greenhouse irrigation and fertilization. We will potentially develop protocols for growers who wish to build irrigation control systems from inexpensive component parts. Currently, we are able to irrigate plants based on VWC measurements from capacitance sensors. While sensor-automation improves the accuracy of greenhouse irrigation, there are only limited predictive models that integrate environmental control and irrigation based on measurements of temperature, humidity, and light. In order to fully integrate our irrigation system into commercial greenhouses, it is vital to determine how the greenhouse environment (temperature, light, and relative humidity) affects plant water use and develop predictive models. This will overlap with collaborative projects with GA described under Topic 2. Interdependence and coordination: ME will be the lead station and will work closely with GA. OH will provide information pertaining to its experience with different volumetric water content sensors. 6. Improve sensor control of the greenhouse aerial environment (light, carbon dioxide, temperature, and moisture). NY: The objective of work in NY is to add to current daily light integral and CO2 concentration algorithm to include consideration of adding limited air conditioning/dehumidification capacity to a greenhouse to increase the number of hours during which CO2 can be added economically to reduce the need for supplemental light to achieve the same plant growth. This algorithm will consider on/off peak electric rate schedules. NY also plans to develop a control algorithm to do the above considering hourly ("day ahead") electric rate schedules. This is also to be done first in a simulation mode. Finally, NY will program and test the algorithms in a working greenhouse. These three objectives will be met first through simulation using real weather data as input. The next step will be to transfer the code to a control program. Labview is a probable first step to port the code, followed by porting it to a language such as C which permits one to create an executable control program. Close collaboration has been established with a local firm to commercialize the results and they are leading the effort to link to current suppliers of commercial greenhouse environment controllers. NE will investigate leaf surface moisture control that is needed for reducing crop disease potential. The overall goal is to advance and assist greenhouse and nursery production by improving utilization of energy and environment moisture control, ultimately leading to higher profitability. Interdependence and coordination: NY will be the lead station. AZ and NJ will provide information pertaining to greenhouse cooling. NE will provide information pertaining to greenhouse moisture control through the evaluation of non-contact infrared temperature sensors to monitor dew point temperatures on interior surfaces of the glazing, floor, and plant canopy. Topic 4: Environmental effects on plant composition 7. Develop greenhouse design and management protocols to maintain high nutrition values of vegetable crops grown under various environments. AZ will optimize high value protein production using controlled environment agriculture technologies in greenhouses and also indoor production facilities. CT will examine how the composition of a nutrient solution changes as it is continuously recirculated to the crop, in comparison to solutions that are used to water plants only once. These changes in nutrient solution due to recirculation will be correlated with changes in plant tissue composition. The results of such studies could be used to modify nutrient solution protocols and recipes to improve production and dietary quality of vegetable crops grown with recirculated nutrient solutions. A tomato crop grown in rock wool is used in long-term experiments. The root medium is watered with a slight excess volume of solution, which is collected in a reservoir. This drained solution is either recycled to the plants or discarded. A complete analysis of the composition of the solution is done at two-week intervals. Plant growth, fruit yield, quality and tissue composition are measured and related to changes in nutrient solution composition brought about by recycling the waste solution. CT will study the effect of season or environment and nutrient solution composition on plant metabolites in hydroponically grown lettuce. The results of this study will be used to modify nutrient solution protocols and recipes to improve production and maintain a more constant dietary quality of vegetable crops grown in hydroponics. Successive plantings will be grown throughout the year, and the nutrient solution will altered over the season to balance the nutrient uptake of the root with the carbon assimilation of the shoot. Plant tissue will be harvested at the end of the day and night, to examine metabolite concentrations and their diurnal variation. Interdependence and coordination: AZ will be the lead station. CT will provide information pertaining to the changes in nutrient solution composition during continuous recirculation. In addition, CT will provide information pertaining to seasonal, environmental, and nutrient solution composition effects on plant metabolites. 8. Develop greenhouse design and management protocols to maximize production of beneficial compounds such as phytochemicals and biopharmaceuticals. NY will start a new SBIR project involving environmental manipulation to increase production of valuable chemicals from GMO plants, preferably through chloroplast expression. We are actively exploring GMO opportunities both pharmacological (though we do not have a good candidate for this yet) and otherwise. The above-mentioned SBIR project will quantify transgenic protein as a percent of total protein using cellulase in tobacco as a model system. The committee also propose to develop communication and information exchange platform within NE-1017, in order to identify multi-state collaborative areas and extramural funding sources for enhancing phytochemicals, biopharmaceuticals and other high value proteins in plants. We observed that several biotechnology industries expanded their capability in controlled environments based on their awareness of its significance in product development and commercialization. We will invite such industries in our communication platform for future collaboration and interactions between industry and academia. This platform will be the foundation to develop bioscience based technologies important for human wellness, which will enhance further development of this emerging bioscience area and related industries. Interdependence and coordination: NY will be the lead station. NJ and AZ will provide information pertaining to their efforts to improve the quantity of antioxidants in fruits and vegetables. Topic 5: Natural ventilation design and control 9. To continue our efforts to use CFD techniques to evaluate greenhouse natural ventilation systems. AZ has considerable expertise in this area and will continue to use Computational Fluid Dynamics (CFD) techniques to evaluate whole greenhouse ventilation rates as well as ventilation rates in selected plant canopy zones. This approach will enable us to analyze the effect of various ventilation designs and cropping configurations especially in the canopy zone. Simulating the presence of plants in greenhouses using the porous media approach as well as the use of comprehensive solar radiation models for the CFD analysis of natural ventilation are relatively novel approaches that will be further studied. Simulations and experiments to validate CFD models that combine natural ventilation and fog cooling will be performed. AZ will also have a very active role in co-chairing the establishment of a new working group on Computational Fluid Dynamics use in Controlled Environment Agriculture Systems of the International Society for Horticultural Sciences. NJ has experience using CFD techniques to simulate heat dissipation in greenhouse floor heating systems. NJ will contribute to the efforts proposed by AZ. Interdependence and coordination: AZ will be the lead station. NJ will provide information pertaining to its experience with CFD techniques for greenhouse floor heating. 10. Continue efforts to improve the efficiency and effectiveness of greenhouse fog cooling systems. The goal of this work will be to develop and validate high-performance control strategies (using neural networks) for fogging systems that will enable or improve year-round cultivation in naturally ventilated greenhouses equipped with fog cooling systems. Sap flow measurements will be made to fine-tune the selected transpiration models that will be used in the control strategy. The dynamic responses of plants to fog cooling (transpiration, leaf temperature, stomatal conductance, etc.), the effect of fogging on plant microclimate, plant status, yield and quality will be determined. The result will be improved control strategies for fog cooling systems used in greenhouses. AZ and NJ will each conduct research in this area, share information and provide recommendations to the greenhouse industry. In addition, NJ will analyze and compare the costs of fan-forced versus natural ventilation systems. Such an analysis will include (but is not limited to): " The reduced cost of lower energy consumption, lower operating costs, and lower maintenance costs. " The returns resulting from higher crop yields and higher quality plants because of reduced heat and disease stress. Interdependence and coordination: AZ will be the lead station. NJ will provide information pertaining to fog cooling systems for orchid production. 11. Improve control strategies as an alternative to existing vent control systems. This effort aims to develop a control strategy for the inlet control in a natural ventilation system based on the concept of the neutral pressure plane for naturally ventilated greenhouses. The approach aims to facilitate faster calculations and to establish a real-time control strategy for natural ventilation systems. However, this approach has not been used in real-life greenhouse settings because of the need for accurate pressure coefficient data that require careful measurement. We propose to implement this approach in real-life greenhouse settings because of the advancements in sensor technology: the pressure sensors are commercially available and are relatively inexpensive. Therefore, real-time measurements can be made to determine actual pressure coefficients for use in model simulations, and improved control strategies can be developed as alternatives to existing vent control systems (e.g., LaFrance, 2006; LaFrance and Brugger, 2006). Other alternatives will also be evaluated such as the use of wind direction, wind speed and outside air temperature measurements to estimate the magnitude of localized pressure coefficients. In support of this effort, the use of neural network (NN) and neuro-fuzzy (NF) models and control systems will also be evaluated. For mechanical ventilation systems, NY has developed a system of using pressure differences between the inside and outside of the greenhouse environment to control the speed of the air entering the greenhouse by adjusting the position of the ventilation window. NY's experience will support the efforts described under this objective. Interdependence and coordination: AZ will be the lead station. NY will provide information pertaining to its efforts using pressure differences to control ventilation inlet openings.

Measurement of Progress and Results

Outputs

• Decision support system for the combined heat and power output of a landfill-gas fired microturbine system.
• Procedures for just-in-time irrigation for crops grown on flooded floors.
• Procedures for using soil (media) moisture sensors to optimize crop irrigation.
• Threshold limits for sodium, chloride, (bi)carbonates, and total conductivity for vegetative annuals grown using conventional (overhead) and sub-irrigation systems.
• Method to determine the capillary waterflow in commercial crop mixes.
• Method(s) to prevent the spread of disease in irrigation systems that recycle water.
• Report on ion buildup and uptake in reciculating nutrient solutions.
• Characterization of root exudates in sub-irrigation systems.
• Report on the potential of limited air conditioning as an improvement to greenhouse environmental control.
• Methods to reduce energy consumption in commercial greenhouse production.
• Evaluation of environmental control methads that enhance the nutritional values of certain greenhouse vegetable crops.
• Evalaution of phytochemical and biopharmaceutical compounds in certain greenhouse crops.
• CFD models of greenhouse natural ventilation and fog cooling.
• Feasibility study of various energy conservation measures and alternative energy sources.
• Feasibility study on the costs and returns of improved nutrient delivery systems.
• Feasibility study on using natural ventilation systems.

Outcomes or Projected Impacts

• Evaluation of biomass as a replacement fuel for propoane and natural gas.
• Optimized Argus Nutrient Delivery System.
• Improved measurement and control techniques for using soil moisture sensors for crop irrigation.
• Improved nutrient delivery systems that effectively incorporate recycling of nutrient solutions while maintaining optimum plant health and quality.
• Improved grower investment advice for energy efficient use of heating fuels, including alternative fuels.
• Improved understanding of greenhouse water use to allow for a reduction in water use as an input to crop production, including in semi-arid regions.
• Improved natural ventilation models using CFD techniques, resulting in real-time control of natural ventilation of greenhouses.
• Improved collaboration and information exchange with commercial greenhouse manufacturers represented by the NGMA (National Greenhouse Manufacturers' Association).
• Commercial growers will have economic data on which to base decisions regarding: Switching to various energy conservation measures and alternative energy sources, adopting improved nutrient deliver systems, and using natural ventilation systems.

Milestones

(2009): <ul><li>Work in progress on alternative energy sources, and energy savings and management strategies (NE, NY, NJ, OH, KY, AZ, and MI). <li>Work in progress on crop irrigation techniques, including sensor technology and optimized control (AZ, NY, CT, OH, NE, PA, KY, ME, and GA). <li>Sharing of results with Extension outreach audiences, and scientific and industry communities (All).</ul>

(2010): <ul><li>Development of CFD models for natural ventilation as well as crop irrigation strategies (AZ, NY, NJ, CT, OH, NE, PA, KY, ME, and GA). <li>Work in progress on disease prevention and nutrient fate in recirculating irrigation systems (CT, ME, GA, NY, OH, and PA). <li>Sharing of results with Extension outreach audiences, and scientific and industry communities (All).</ul>

(2011): <ul><li>Work in progress on root exudates in sub-irrigation systems (CT, NY). <li>Work in progress on phytochemical and bio-pharmaceutical compounds in certain greenhouse crops (NY, AZ). <li>Sharing of results with Extension outreach audiences, and scientific and industry communities (All). <li>Report on economic feasibility of using natural ventilation systems.</ul>

(2012): <ul><li>Report on suitable alternative energy sources. <li>Report on energy savings and management strategies. <li>Report on crop irrigation techniques, including sensor technology and optimized control. <li>Work in progress on improved working relationship with industry organizations (e.g., NGMA). <li>Sharing of results with Extension outreach audiences, and scientific and industry communities. <li>Report on economic feasibility of various energy conservation measures and alternative energy sources.</ul>

(2013): <ul><li>Report on disease prevention and nutrient fate in recirculating irrigation systems. <li>Report on root exudates released in sub-irrigation systems. <li>Report on phytochemical and bio-pharmaceutical compounds in certain greenhouse crops. <li>Sharing of results with Extension outreach audiences, and scientific and industry communities. <li>Report on economic feasibility of the costs and returns of improved nutrient delivery systems.</ul>

Projected Participation

View Appendix E: Participation

Outreach Plan

Our committee has a long history of transferring technology to the commercial greenhouse industry. For example, the air-inflated double-layer polyethylene greenhouse covering system (now an ASABE Historic Landmark), greenhouse energy curtains, greenhouse floor heating, seedling transplanting mechanism, hydroponic production systems, and supplemental light control to a daily light integral. All these developments are currently used across the industry.


The several committee members have (partial) Extension appointments and are well-aware of the issues facing the greenhouse industry and have excellent opportunities to inform the industry of the discoveries made through the research proposed. We will use the following methods for communicating results: Extension meetings, workshops, publications including news letters, fact sheets, bulletins, conference proceedings and journal articles, web sites, as well as presentations at regional and national meetings. The Extension community already implemented a system of identifying deliverables and measuring impacts (Extension Evaluation and Outcome Reporting), and that system will also be used to evaluate the value of the activities proposed under the various objectives.


We are aware of eXtension's Communities of Practice, but have not investigated its particular value to the research efforts described in this proposal. If it turns out there are significant advantages, we will certainly investigate how best to incorporate this opportunity in the work proposed.

Organization/Governance

The NE-1017 committee (and its predecessors) has organized itself by annually appointing an incoming secretary, who then serves as the secretary for the following year (including the next annual meeting). After completing a term (one year) as secretary, the individual served as the committee chair the following year. We did not have the position of vice chair (chair elect). Therefore, officers served for two-year terms. This limited the time commitment requested from incoming officers and since the committee was small and informal, sufficient institutional memory could be tapped in case procedural questions came up. This organizational model has worked well for many years, and we plan to continue with it if our proposal is approved for continued funding.
Annual meetings were organized on a rotating basis after the membership was polled for availability and interest. The model has work well also, and we plan to continue it as well. Many of the participating members meet each other at other scientific meetings throughout the year, ensuring sufficient opportunity for interaction in addition to the annual project meetings.

Literature Cited

Topic 1: Energy conservation and alternative energy sources


References related to this topic (excluding those listed on the MI web site)


Both, A.J., D.R. Mears, T.O. Manning, E. Reiss, P.P. Ling. 2007. Evaluating energy savings strategies using heat pumps and energy storage for greenhouses. ASABE paper No. 07-4011. ASABE, 2950 Niles Road, St. Joseph, MI 49085-9659, USA. 16 pp.


Both, A.J., E. Reiss, D.R. Mears, and W. Fang. 2005. Designing environmental control for greenhouses: Orchid production as example. Acta Horticulturae 691(2):807-813.


Brennan, M., D. Specca, B. Schilling, D. Tulloch, S. Paul, K. Sullivan, Z. Helsel, P. Hayes, J. Melillo, B. Simkins, C. Phillipuk, A.J. Both, D. Fennell, S. Bonos, M. Westendorf, and R. Brekke. 2007. Assessment of biomass energy potential in New Jersey. New Jersey Agricultural Experiment Station Publication No. 2007-1. Rutgers, the State University of New Jersey, New Brunswick, NJ.


Topic 2: Water and nutrient solution management


References related to this topic


Buenrostro-Nava, M.T., P.P. Ling, and J.J. Finer. 2005. Development of an automated image acquisition system for monitoring gene expression and tissue growth. Transactions of the ASAE 48(2):841-847.


Burnett, S.E., M.W. van Iersel, and P.A. Thomas. 2006. Medium-incorporated PEG-8000 affects elongation, growth, and whole-canopy carbon dioxide exchange of Tagetes patula. HortScience 41:124-130.


Dayan, E., E. Presnov and L.D. Albright. 2005. Methods to estimate and calculate lettuce growth. Acta Horticulturae 674:305-312.


Ferentinos, K.P. and L.D. Albright. 2003. Fault detection and diagnosis in deep-trough hydroponics using intelligent computational tools. Biosystems Engineering 84(1): 13-30.


Ferentinos, K.P., L.D. Albright and B. Selman. 2003. Neural network-based detection of mechanical, sensor and biological faults in deep-trough hydroponics. Computers and Electronics in Agriculture. 40:65-85.


Giacomelli, G.A., 2003. Engineering Design of Plant Nutrient Delivery Systems. ACTA Horticulturae 648:71-82. ISHS South Pacific Soilless Culture Conference, Palmerston North, New Zealand. February 10-13.


Glynn, C., D.A. Herms, M. Egawa, R.C. Hansen, and W.J. Mattson. 2003. Effects of nutrient availability on biomass allocation as well as constitutive and induced herbivore resistance in poplar. Oikos 101: 385-397.


Hale, B.K., D.A. Herms, R.C. Hansen, T.P. Clausen and D. Arnold. 2005. Effects of drought stress and nutrient availability on dry matter allocation, phenolic glycosides, and rapid induced resistance of poplar to two lymantriid defoliators. Journal of Chemical Ecology 31(11): 2601-2620.


Heinemann, P.H., G. Preti, C.J. Wysocki, R.E. Graves, S.P. Walker, D.M. Beyeer, E.J. Holcomb, C.W. Heuser, and F.C. Miller. 2003. In-Vessel Processing of Spent Mushroom Substrate for Odor Control. Applied Engineering in Agriculture 19(4): 461-471.


Holcomb, E.J., Charles Heuser, Paul Heinemann and Fred Miller. 2005. Nutrient changes in spent mushroom substrate during composting. Mushroom News 53(10):6-11.


Ishii, M., S. Sase, H. Moriyama, C. Kubota, K. Kurata, M. Hayashi, A. Ikeguchi, N. Sabeh. P. Romero, and G.A. Giacomelli. 2006. The effect of evaporative fog cooling in a naturally ventilated greenhouse on air and leaf temperature, relative humidity, and water use in a semiarid climate. Acta Horticulturae 719:491-498.


Kacira, M., S. Sase, L. Okushima, and P.P. Ling. 2005. Plant response-based sensing for control strategies in sustainable greenhouse production. J. Agric. Meteorology 61(1):15-22.


Katzman, L.S. 2003. Influence of plant age, inoculum dosage, and nutrient solution temperature on the development of Pythium aphanidermatum in hydroponic spinach. Ph.D. Dissertation, Cornell University.


Kubota, C., M. Hayashi, Y. Fukuda, S. Yokoi, and S. Sase. 2006. Using ventilation-evaporation-temperature-humidity (VETH) chart software for developing a strategy for evaporative cooling of semiarid greenhouses. Acta Horticulturae 719:483-490.


Linker, R., J. Mathieu and L.D. Albright. 2005. A user-friendly, Internet-based, version of the NICOLET simulation model for lettuce. Acta Horticulturae 675:337-342.


Mathieu, J., R. Linker, L. Levine, L. Albright, A.J. Both, R. Spanswick, R. Wheeler, E. Wheeler, D. deVilliers, R. Langhans. 2006. Evaluation of the NiCoLet model for simulation of short-term hydroponic lettuce growth and nitrate uptake. Biosystems Engineering 95(3):323-337.


Mathieu, J.J. 2004. Lettuce crop evapotranspiration, nitrate uptake, and growth mechanistic simulation modeling: For use in fault detection in hydroponic production systems. Ph.D. dissertation. Cornell University Libraries. 246 pp.


Montesano, F., and M.W. van Iersel. 2007. Calcium can prevent toxic effects of Na+ on tomato leaf photosynthesis, but does not restore growth. Journal of the American Society for Horticultural Science 132: In press.


Montgomery, J. 2005. Evaluation of solid artificial media for lettuce seedling growth and anchorage. M.S. Thesis, Cornell University Libraries, Ithaca, NY. 77 pp.


Nemali, K.S. and M.W. van Iersel. 2006. An automated system for controlling drought stress and irrigation in potted plants. Scientia Horticulturae 110:292 297.


Nemali, K.S., F. Montesano, S.K. Dove, M.W. van Iersel. 2007. Calibration and performance of moisture sensors in soilless substrates: ECH2O and Theta probes. Scientia Horticulturae 112:227-334.


Ono, E. 2001. Monitoring of Nutrient Solution for Hydroponically Grown Sweetpotato (Ipomoea batatas). Ph.D. Dissertation, The University of Arizona.


Ono, E., K. Jordan and J.L. Cuello. 2003. Monitoring the Temporal Variations of Nitrate, Potassium and Manganese in Sweetpotato Hydroponic Solutions for Space Life Support Application. Proceedings of the 33rd International Conference on Environmental Systems. SAE: Engineering Society for Advanced Mobility in Land, Sea, Air and Space. 03ICES-191.


Prenger, J.J. 2003. Development of a Plant Response Feedback Irrigation Control System Based on Crop Water Stress Index and Evapotranspiration Modeling. M.S. Thesis, The Ohio State University.


Prenger, J.J., P.P. Ling, R.C. Hansen and H.M. Keener. 2005. Plant response-based irrigation control system in a greenhouse: system evaluation. Transactions of the ASAE 48(3): 1175-1183.


Sabeh, N.C., G.A. Giacomelli, and C. Kubota. 2006. Water use for pad and fan evaporative cooling of a greenhouse in semi-arid climate. Acta Horticulturae 719:409-416.


Sase, S., M. Ishii, H. Moriyama, C. Kubota, K. Kurata, M. Hayashi, N.C. Sabeh, P. Romero, G.A. Giacomelli. 2006. Effect of natural ventilation rate on relative humidity and water use for fog cooling in a semiarid greenhouse. Acta Horticulturae. 719:385-392.


Scoggins, H.L. and M.W. van Iersel. 2006. In situ probes for measurement of EC of soilless substrates: effects of temperature and substrate moisture content. HortScience 41:210-214.


Smith, B.R., P.R. Fisher, and W.R. Argo. 2004. Water-soluble Fertilizer Concentration and pH of a Peat-based Medium Affect Growth, Nutrient Uptake, and Chlorosis of Container-grown Seed Geraniums (Pelargonium x hortorum L.H.Bail). J. of Plant Nutrition. 27(3): 497-524.


Son, J-E. M-M. Oh, Y-J. Lu, K-S. Kim, and GA. Giacomelli. 2006. Nutrient-Flow Wick Culture System for Potted Plant Production: System Characteristics and Plant Growth. Scientia Horticulturae 107: 392-398.


Starman, T.W. and L. Lombardini. 2006. Growth, gas exchange, and chlorophyll fluorescence of four ornamental herbaceous perennials during water deficit conditions. J. Amer. Soc. Hort. Sci. 131(4):469-475.


van Iersel, M.W., S.E. Burnett, and S. Dove. 2006. Increasing irrigation efficiency: Water requirements of petunia and salvia. Proceedings of the Southern Nursery Association Research Conference, Atlanta, Georgia. 51:640-643.


Wik, R.M. (Advisor: Fisher, P.R.) 2003. The effect of iron form, substrate-pH, and iron efficiency on plant nutritional status. M.S. Dissertation, University of New Hampshire.


Zolnier, S., G.B. Lyra and R.S. Gates. 2004. Evapotranspiration estimates for greenhouse lettuce using an intermittent nutrient film technique. Transactions of the ASAE, 47(1):271-282.


Zolnier, S., R.S. Gates, R.L. Geneve and J.W. Buxton. 2003. Evapotranspiration-based mist control for poinsettia propagation. Transactions of the ASAE 46(1):135-145.


Topic 3: Sensors and control systems


References related to this topic


Albright, L.D. Method for controlling greenhouse light. United States Patent 5,818,734. October 6, 1998.


Albright, L.D., K.P. Ferentinos, I. Seginer, J.W. Ho and D. de Villiers. Systems and methods for providing optimal light-CO2 combinations. United States Patent 7,184,846, February 27, 2007.


Burnett, S.E. and M.W. van Iersel. 2008a. Water use efficiency and morphology of Gaura lindhiemeri Siskiyou Pink grown in capacitance sensor controlled irrigation. HortScience (In Press). MAFES Publication #2977.


Burnett, S.E. and M.W. van Iersel. 2008b. Watering, Irrigation Systems, and Control. In: K. Williams (ed.). Water and Nutrient Management for Floriculture Crops, 2nd ed. Ball Publishing, West Chicago, Ill. (In Press).


van Iersel, M.W., S.E. Burnett, and S. Dove. 2006. Increasing irrigation efficiency: Water requirements of petunia and salvia. Proc. Southern Nurs. Assn. Res. Conf. 51:640-643.


van Iersel, M.W., J.G. Kang, and S. Burnett. 2007. Making greenhouse irrigation more efficient: Effects of substrate water content on the growth & physiology of vinca (Catharanthus roseus). Proc. Southern Nurs. Assn. Res. Conf. (In Press).


Topic 4: Environmental effects on plant composition


References related to this topic


Alba, R., Cordonnier-Pratt, M.M., Pratt, L.H., 2000. Fruit-localized phytochromes regulate lycopene accumulation independently of ethylene production in tomato. Plant Physiol. 123: 363-370.


Alvarez, M.L, Pinyerd, H., Rigano, M. M., Pinkhasov, J., Walmsley, A.M., Mason, H. S., Cardineau, G. A. 2006. Plant-made subunit vaccine against pneumonic and bubonic plague is orally immunogenic in mice. Vaccine 24: 2477- 2490.


Briskin, D.P. and Gawienowski M.C. 2001. Differential effects of light and nitrogen on production of hypericins and leaf glands in Hypericum perforatum. Plant Physiol Biochem. 39:1075-1081.


Couceiro, M.A., F. Afreen, S.M.A. Zobayed, and T. Kozai 2006. Variation in concentrations of major bioactive compounds of St. John's Wort: Effect of harvesting time, temperature, and germplasm. Plant Sci. 170:128-134.


Fanasca, S., Colla, G., Rouphael, Y., Saccardo, F., Maiani, G., Venneria, E., Azzini E. 2006. Evolution of nutrient value of two tomato genotypes grown in soilless culture as affected by macrocation proportions. HortScience 41:1584-1588.


Krauss, S., Schnitzler, W.H., Grassmann, J. Woitke, M. 2006. The influence of different electrical conductivity values in a simplified recirculating soilless system on inner and outer fruit quality characteristics of tomato. J. Agric. Food Chem. 54: 441-448.


Kroggel, M., Katherine, D., Kubota, C., Thomson, C. 2007. Changes in concentrations of lycopene and total soluble solids of hydroponic tomato fruit as affected by greenhouse environmental conditions. HortScience 42: 923. (abstract)


Krumbein, A., Schwarz, D., Kläring, H.-P. 2006. Effects of environmental factors on carotenoid content in tomato (Lycopersicon esculentum (L.) Mill.) grown in a greenhouse. J. Appl. Bot. Food Quality 80: 160-164.


Murch SJ, Haq Kamran, Vasantha Rupasinghe HP, Saxena PK. 2003. Nickel contamination affects growth and secondary metabolite composition of St. John's wort (Hypericum perforatum L.). Env Exp Bot 49: 251-257.


Twyman, R.M., Stoger, E., Schillberg, S., Christou, P., Fischer, R. 2003. Molecular farming in plants: host systems and expression technology. Trends Biotech. 21: 570-578.


Wu, M., Kubota, C. 2008. Effects of high electrical conductivity of nutrient solution and its application timing on lycopene, chlorophyll and sugar concentrations of hydroponic tomatoes during ripening. Scientia Horticulturae (in press).


Topic 5: Natural ventilation design and control


References related to this topic


Bailey, B.J. 1985. Microclimate, physical processes and greenhouse technology. Acta Hortic. 174: 35-42.


Boulard, T. 2004. Modeling the distributed greenhouse climate at crop and leaf level. In Proc. of International Workshop on Environmental Control and Structural Design for Protected Cultivation, June 14-16, Suwon, Korea, pp 44-53.


Brockett, B. L. and L. D. Albright. 1987. Natural Ventilation in Single Airspace Buildings. Journal of Agricultural Engineering Research 37: 141-154.


Fatnassi, H., T. Boulard, C. Poncet and M. Chave. 2006. Optimisation of Greenhouse Insect Screening with Computational Fluid Dynamics. Biosystems Engineering 93 (3): 301-312.


Kacira, M. and S. Sase. 2004. Optimization of vent configuration by evaluating greenhouse and plant canopy ventilation rates under wind induced ventilation. Transactions of the ASAE 47(6): 2059-2067.


Kacira, M., S. Sase, L. Okushima and P. P. Ling. 2005. Plant response based sensing and control strategies in sustainable greenhouse production. Journal of Agricultural Meteorology of Japan 61(1): 15-22.


LaFrance, T. and M. Brugger. 2006. Determining pressure coefficients for natural ventilation purposes by computational fluid dynamics modeling. An ASAE Meeting Presentation, Paper No: 064093, St. Joseph, MI.


LaFrance, T. 2005. Determining pressure coefficients for natural ventilation purposes by computational fluid dynamics modeling. M.S. Thesis. The Ohio State University, Department of Food, Agricultural and Biological Engineering.


Lee, I., T. H. Short, S. Sase, L. Okushima, and G. Y. Qiu. 2000. Evaluation of structural characteristics of naturally ventilated multispan greenhouses using computer simulation. Japanese Agric. Res. Quarterly 34(4): 245-255.


Montero, J.I. and A. Anton. 1990. Greenhouse cooling during warm period. Acta Horticulture 245: 49-60.


Montero, J.I. and I. Segal. 1993. Evaporative cooling of greenhouses by fogging combined with natural ventilation and shading. In: Proceedings of the International Workshop on Cooling Systems for Greenhouses Agritech, Tel Aviv, Israel, May 2-6, 1993.


Ould Khaoua, S. A., P.E. Bournet, C. Migeon, T. Boulard, and G. Chassériaux. 2006. Analysis of Greenhouse Ventilation Efficiency based on Computational Fluid Dynamics. Biosystems Engineering, 95(1), 83-98.


Reiss, E., D.R. Mears, T.O. Manning, G.J. Wulster, and A.J. Both. 2007. Numerical modeling of greenhouse floor heating. Transactions of the ASABE 50(1): 275-284.


Sase, S., E. Reiss, A.J. Both, and W.J. Roberts. 2002. A natural ventilation model for open-roof greenhouses. ASAE paper No. 02-4010. ASAE, 2950 Niles Road, St. Joseph, MI 49085-9659, USA. 9 pp.

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